310S不锈钢管 2520不锈钢管 耐热耐高温不锈钢管-浙江至德钢业有限公司 http://fuxinfengshuo.top/ S31008不锈钢管 为什么310s不锈钢材料很难车床加工 http://fuxinfengshuo.top/post/128.html <p>&nbsp; 一般钢材在切削温度的作用下,切屑切离部位的金属强度和硬度,将随着温度的升高而明显下降,使切屑比较容易切离。而<strong>310s不锈钢</strong>的特性之一就是高温强度高、硬度高。例如奥普通<a href="http://fuxinfengshuo.top" target="_blank" title="310s不锈钢"><strong>310s不锈钢</strong></a>在温度高达1000℃时仍不降低其机械性能,所以切屑就不易被切离,刀具就容易被磨损。因此,在常温下即使机械性能各项指标完全相同的情况下,切去一定体积的310s不锈钢切屑要比切去相同体积的普通碳素钢切屑所消耗的能量多得多,而且刀具也容易被磨损。</p><p><br/></p><p>&nbsp;310s不锈钢材料韧性大,对其它金属材料的亲和性强。因此,和其它金属材料相接触,在一定压力的作用下,就会产生粘附现象。粘附现象的强弱,除决定于不锈钢材料本身的特性以外,还与相接触材料的性质、硬度、表面光洁度、环境温度、接触压力、相对运动速度和接触表面之间的润滑条件等因素有关。 完全相同的不锈钢材料接触,粘附现象最为严重。例如用奥氏体310s不锈钢制造螺栓和螺母,或者同时用2Cr13马氏体不锈钢制造螺栓和螺母,拧合后很容易产生“咬死”现象。为了避免产生这种“咬死”现象,螺栓和螺母必须采用不同型号的不锈钢。例如螺栓用310s不锈钢制造,螺母就应该采用2Cr13不锈钢制造;反之,螺栓用2Cr13不锈钢制造,螺母就应该采用310s不锈钢制造。<br/></p><p><br/></p><p>&nbsp; &nbsp; 扩大相接触零件的硬度差别,提高接触表面光洁度,在相接触的表面之间添加合适的润滑剂,可以减弱310s不锈钢的粘附作用。增加接触压力,提高相对运动速度和增高接触部位的温度,会大大增强310s不锈钢的粘附作用。在高温作用下的粘附现象,实际上还包括金属的熔着现象,所以往往通称为粘附、熔着现象fuxinfengshuo.top</p><p><br/></p> Thu, 14 Mar 2019 10:00:07 +0800 310L不锈钢化学成及耐蚀性能特点 http://fuxinfengshuo.top/post/127.html <p>310L不锈钢是在310S不锈钢基础上发展起来的超低碳奥氏体不锈钢,改善了0Cr25Ni20的耐晶间腐蚀能力,此钢主要用于耐强氧化性酸性环境腐蚀的设备、装置和部件,解决了焊后耐蚀性劣化问题。 310L不锈钢具有良好的耐点蚀性能,其点蚀电位远高于304L,同时310S不锈钢的耐应力腐蚀性能同样优于304L不锈钢。<br/></p><p><br/></p><p>310L不锈钢工艺性能</p><p><br/></p><p>&nbsp; &nbsp;1.热加工&nbsp; &nbsp;适宜的热加工温度为900~1150℃</p><p><br/></p><p>&nbsp; &nbsp;2.冷加工&nbsp; 此钢适用于各种冷加工操作,冷加工的中间热处理温度以1000~1150℃为宜,其冷成型性能类似于18-8型不锈钢。</p><p><br/></p><p>&nbsp; &nbsp;3.热处理&nbsp; &nbsp;固溶处理温度为1000~1150℃。消除应力退火温度为850~950℃,保温10~15min后空冷。</p><p>&nbsp;</p><p>&nbsp; &nbsp;4.焊接&nbsp; &nbsp;310L不锈钢焊接性能良好,可采取TIG,MIG和手工电弧焊等方法进行焊接,在通常情况下,不需要焊前预热,在各种焊接方法中,手工电弧焊更为合适。焊件厚度≤6mm时,选用直径2.5mm焊条,焊件厚度超过6mm时,则宜选直径≤3.2mm焊条。</p><p><br/></p><p>&nbsp; &nbsp; 在强氧化性的腐蚀环境中,304L的耐蚀性不能满足要求的情况下,可以选用310L不锈钢,如硝酸生产厂的尾气预热器、加热器,冷却器和冷凝器等;硝酸铵厂的硝酸预热器;三氯氰胺厂的反应热蛇形管;丙稀酸纤维厂的硝酸冷凝器、硝酸在沸器;已二酸工厂的再沸器;氧化铀生产中的硝酸设备fuxinfengshuo.top</p><p><br/></p> Thu, 14 Mar 2019 09:51:56 +0800 高温时效处理对310S不锈钢焊接接口性能的影响 http://fuxinfengshuo.top/post/126.html <p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">研究了高温时效前后的</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">焊接样品在燃煤气氛下的碳硫影响。利用金相、扫描电镜</span>/<span style="font-family:宋体">能谱、</span><span style="font-family:Calibri">X</span><span style="font-family:宋体">射线衍射及力学性能测试等分析其形貌、成分结构及性能。结果表明,经不同温度、不同时间在燃煤气氛下时效处理的</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">比未时效处理者腐蚀严重,</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在高于</span>700<span style="font-family:宋体">℃时效后在晶界大量析出σ相,使晶界附近贫</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">,降低了其抗腐蚀性能,同时晶粒长大,冲击韧性明显降低,而且断裂方式也由微孔聚合型断裂转变为典型的解理断裂。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢由于具有优良的耐腐蚀性能,广泛用于船舶、车辆、汽车、宇航、桥梁、建筑、压力容器、贮罐、建筑机械、管线及家用电器等行业。</span>310<span style="font-family:宋体">不锈钢具有优良的高温力学性能及抗高温氧化性能,作为结构材料广泛运用于石化工业[</span><span style="font-family:Calibri">1-3</span><span style="font-family:宋体">],在不锈钢加工工艺中,焊接是最主要的加工技术。特别是石化行业对焊接工艺和质量的要求更高[</span><span style="font-family:Calibri">4-5</span><span style="font-family:宋体">]。过去对</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的高温碳、硫腐蚀作过一些研究,碳易产生晶间腐蚀,硫增加导致热脆性[</span>6-9<span style="font-family:宋体">]。但都局限于原始状态,对于此种材料长时间高温时效处理对其焊接性能有何影响很少报道。本文对普通燃煤中长时间高温时效后的</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的焊接行为进行研究,为石化工业结构材料在高温腐蚀环境中长期使用提供参考。</span>1<span style="font-family:宋体">实验材料及方法将化学成分如表</span><span style="font-family:Calibri">1</span><span style="font-family:宋体">所示的</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">板</span>80mm<span style="font-family:宋体">×</span><span style="font-family:Calibri">20mm</span><span style="font-family:宋体">×</span><span style="font-family:Calibri">5mm</span><span style="font-family:宋体">的试样若干,采用不锈钢焊条氩弧焊对焊成尺寸为</span><span style="font-family:Calibri">160mm</span><span style="font-family:宋体">×</span><span style="font-family:Calibri">20mm</span><span style="font-family:宋体">×</span><span style="font-family:Calibri">5mm</span><span style="font-family:宋体">的试样若干(焊接接口在中间)。与普通燃煤一起装入密封罐体内,在马弗炉中分</span><span style="font-family:Calibri">3</span><span style="font-family:宋体">个温度,</span><span style="font-family:Calibri">3</span><span style="font-family:宋体">个保温时间以表</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">的工艺进行高温时效处理,以便研究煤中的碳、硫对焊缝的影响(因为</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">常用在煤转换化工中)。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">将不同温度、不同时间处理的试样采用</span>10%<span style="font-family:宋体">的氯化铁腐蚀溶液腐蚀,在</span><span style="font-family:Calibri">XJL-03</span><span style="font-family:宋体">型金相显微镜下观察。拉伸试验在</span><span style="font-family:Calibri">AG-250KNIS</span><span style="font-family:宋体">型拉伸试验机上进行,试样尺寸</span><span style="font-family:Calibri">160mm</span><span style="font-family:宋体">×</span><span style="font-family:Calibri">10mm</span><span style="font-family:宋体">×</span><span style="font-family:Calibri">5mm</span><span style="font-family:宋体">。在摆锤冲击试验机上按照国标</span><span style="font-family:Calibri">GB2106</span><span style="font-family:宋体">-</span><span style="font-family:Calibri">1980</span><span style="font-family:宋体">作“</span><span style="font-family:Calibri">V</span><span style="font-family:宋体">”型冲击韧性实验,试样尺寸为</span><span style="font-family:Calibri">80mm</span><span style="font-family:宋体">×</span><span style="font-family:Calibri">20mm</span><span style="font-family:宋体">×</span><span style="font-family:Calibri">5mm</span><span style="font-family:宋体">(焊缝在沿试样长度方向的中间)。对断口使用</span><span style="font-family:Calibri">JSM-6700F</span><span style="font-family:宋体">型扫描电子显微镜(</span><span style="font-family:Calibri">SEM</span><span style="font-family:宋体">)结合能谱分析(</span><span style="font-family:Calibri">EDS</span><span style="font-family:宋体">)。采用</span><span style="font-family:Calibri">XRD-7000</span><span style="font-family:宋体">型</span><span style="font-family:Calibri">X</span><span style="font-family:宋体">射线衍射仪对其组织结构进行分析,用铜靶</span><span style="font-family:Calibri">K</span><span style="font-family:宋体">α线(λ</span><span style="font-family:Calibri">=0.15406nm</span><span style="font-family:宋体">),扫描速度</span><span style="font-family:Calibri">4</span><span style="font-family:宋体">°</span><span style="font-family:Calibri">/min</span><span style="font-family:宋体">,扫描范围</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">θ取</span><span style="font-family:Calibri">20</span><span style="font-family:宋体">~</span><span style="font-family:Calibri">80</span><span style="font-family:宋体">°。并对高温处理前后材料的化学成分采用能谱和光谱进行定量分析。</span></span></p><p><span style=";font-family:宋体;font-size:14px">2<span style="font-family:宋体">实验结果与分析</span></span></p><p><span style=";font-family:宋体;font-size:14px">2.1</span><span style=";font-family:宋体;font-size:14px">&nbsp;</span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在不同温度下处理的显微组织</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">图</span>1<span style="font-family:宋体">是</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在不同温度下长时间停留后的组织,可以看出,未经过处理的原始试样的显微组织主要是奥氏体和碳化物,晶粒较大,焊缝清晰;经</span>650<span style="font-family:宋体">、</span><span style="font-family:Calibri">720</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃高温时效处理后,晶界明显,有析出物产生,</span><span style="font-family:Calibri">650</span><span style="font-family:宋体">℃与</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃时晶粒基本一致,而在</span><span style="font-family:Calibri">720</span><span style="font-family:宋体">℃时,晶粒长大较为明显,这是不锈钢在</span><span style="font-family:Calibri">700</span><span style="font-family:宋体">℃附近比较敏感,保温时间延长对显微组织影响不大,但能看到在焊缝处有一些黑色点状的物质析出,这是与煤长时间接触,碳的扩散导致一些碳化物的形成,由图</span><span style="font-family:Calibri">2XRD</span><span style="font-family:宋体">中看到明显的碳化物</span><span style="font-family:Calibri">K</span><span style="font-family:宋体">峰。</span></span></p><p><span style=";font-family:宋体;font-size:14px">2.2</span><span style=";font-family:宋体;font-size:14px">&nbsp;</span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">性能测试结果</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">表</span>3<span style="font-family:宋体">是</span></span><a href="http://fuxinfengshuo.top/" target="_self"><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span></a><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在不同温度下长时间停留后性能测试结果。可以看出,</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">经</span>A<span style="font-family:宋体">、</span><span style="font-family:Calibri">B</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">C3</span><span style="font-family:宋体">个工艺处理后对屈服强度和抗拉强度影响不大,只是在</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃处理时有点降低,但对冲击值的影响较大,且随处理温度的升高,冲击值下降越明显。这一方面说明冲击韧性表征温度和缺口的敏感特性,另一方面正如前述显微组织在高温下焊缝处有碳化物相的析出导致其值大大降低。这说明焊缝受温度和时间的影响较大。再者,无论那个工艺,屈服强度在没有焊缝堆积时其值均大于有焊缝堆积的状况,估计在焊缝处造成了一定的应力集中。抗拉强度也有类似的结果,但在</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃时情况则相反,说明高温下晶粒长大后与常温性能不一致。断裂位置在较低温度一般在母材处断裂,而在较高温度</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃下则在焊缝区断裂,说明高温使用对焊缝的影响较大。</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;</span></p><p><span style=";font-family:宋体;font-size:14px">2.3</span><span style=";font-family:宋体;font-size:14px">&nbsp;</span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在不同工艺下处理的</span>XRD</span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">图</span>2<span style="font-family:宋体">是</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在燃煤环境下于</span>800<span style="font-family:宋体">℃保温</span><span style="font-family:Calibri">100h</span><span style="font-family:宋体">后母材和焊缝变化前后的</span><span style="font-family:Calibri">XRD</span><span style="font-family:宋体">图谱。可以看出,不管是母材还是焊缝,原始试样是杂波信号较多的“多相”,经高温处理后变成杂波信号非常少的“均一相”。组织结构没有变化(试验时已进行应力消除)。也说明母材和焊缝,在含碳环境(与煤充分接触)和高温共同作用下没有组织转变。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">碳属间隙型固溶元素,可促使</span>γ相扩大,即碳对奥氏体有稳定化的作用,但是,奥氏体不锈钢的晶间腐蚀倾向通常随碳含量的增高而趋严重。这是因为碳含量越高,晶间沉淀的<span style="font-family:Calibri">Cr23C6</span><span style="font-family:宋体">碳化物越多,晶间贫铬区铬贫乏的程度越严重,对于长时间在燃煤环境下,材料表面有增碳,杂质元素磷和硫易在晶界偏析,导致不锈钢具有晶间腐蚀倾向。对于晶间腐蚀机理,理论研究较多,</span><span style="font-family:Calibri">20</span><span style="font-family:宋体">世纪</span><span style="font-family:Calibri">60</span><span style="font-family:宋体">年代中期以来,贫铬理论被广泛地接受和应用。贫铬理论[</span><span style="font-family:Calibri">10</span><span style="font-family:宋体">]认为,不锈钢发生晶间腐蚀是由晶界贫铬而引起的。碳在高温奥氏体中的溶解度比较大。在高温下溶解碳的奥氏体不锈钢迅速冷却到室温时,碳就会以过饱和的形式固溶。若再将其加热到适当温度并保温足够的时间,过饱和的碳就会以碳化物的形式沉淀出来,导致不锈钢晶界附近贫铬。</span><span style="font-family:Calibri">Cr23C6</span><span style="font-family:宋体">是最主要的碳化物,其沉淀温度为</span><span style="font-family:Calibri">400</span><span style="font-family:宋体">~</span><span style="font-family:Calibri">950</span><span style="font-family:宋体">℃。在较低热处理温度下(</span><span style="font-family:Calibri">650</span><span style="font-family:宋体">℃),在晶界上会有明显的析出物,而在较高的热处理温度下(</span><span style="font-family:Calibri">925</span><span style="font-family:宋体">℃以上),晶界则不会有明显的析出物。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">长时间高温时效处理使</span>310<span style="font-family:宋体">不锈钢晶界上大量析出σ相,造成晶界附近贫</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">,降低了晶界区抗硫腐蚀性能,使硫沿着晶界快速扩散,在合金晶界区处形成腐蚀沟,最终形成腐蚀裂纹。这一点在</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃左右的断口形貌中有所体现(见图</span><span style="font-family:Calibri">5</span><span style="font-family:宋体">和图</span><span style="font-family:Calibri">6</span><span style="font-family:宋体">)。</span></span></p><p><span style=";font-family:宋体;font-size:14px">2.4<span style="font-family:宋体">断口形貌与成分变化</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">图</span>3<span style="font-family:宋体">~图</span><span style="font-family:Calibri">4</span><span style="font-family:宋体">为</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在不同工艺下的冲击和拉伸断口形貌。可以看出,原始试样的拉伸与冲击断口形貌差异较小,均为典型的韧窝特征,说明是韧性断裂,而随处理温度的提高,有撕裂棱出现,发展到</span>800<span style="font-family:宋体">℃时,产生明显的沿晶脆性断裂,这也是在高温下其冲击韧性较低的原因。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">表</span>4<span style="font-family:宋体">为</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在不同工艺下表面和心部合金元素变化,可以看出,经长时间高温时效,所有试样表面的</span>C<span style="font-family:宋体">、</span><span style="font-family:Calibri">S</span><span style="font-family:宋体">较心部的高,但较低温度时他们的差别较大,而较高温度</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃时,表面和心部的差别减小,这可能是较高温度表面的积碳燃烧的结果,使得表面留存较少的碳。对照化学分析认为经过一定温度的加热,材料中的</span><span style="font-family:Calibri">C</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">S</span><span style="font-family:宋体">有一定的增加,但增加很小,不足</span><span style="font-family:Calibri">5%</span><span style="font-family:宋体">,而且温度、时间对其影响很小。</span></span></p><p><span style=";font-family:宋体;font-size:14px">3<span style="font-family:宋体">结论</span></span></p><p><span style=";font-family:宋体;font-size:14px">1<span style="font-family:宋体">)</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在燃煤环境下长时间高温时效处理,组织结构变化不大,只是在</span>720<span style="font-family:宋体">℃时晶粒长大明显,且碳、硫元素的增长不明显;</span></span></p><p><span style=";font-family:宋体;font-size:14px">2<span style="font-family:宋体">)</span></span><span style=";font-family:宋体;font-size:14px">310S<span style="font-family:宋体">不锈钢</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">焊接件经高温时效处理后,屈服强度和抗拉强度随温度提高或时间的延长变化较小,而冲击韧性则随温度的提高下降明显,下降幅度达到</span>80%<span style="font-family:宋体">以上。断裂机制则由原始试样的韧性断裂转变为沿晶解理的脆性断裂。</span></span></p> Sat, 15 Dec 2018 20:15:25 +0800 不锈钢管线焊接在模块化天然气处理厂项目中的应用 http://fuxinfengshuo.top/post/125.html <p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">奥氏体不锈钢管线因其具有强度高、塑韧性好、防腐性能好,所以在工艺管线中得到广泛应用。澳大利亚液化天然气处理厂项目,位于澳大利亚西北部的巴罗岛,属</span>A<span style="font-family:宋体">级自然保护区,因此采取模块化方式进行建造。奥氏体不锈钢是该天然气处理厂项目工艺管线重要组成部分,本文将对其焊接性能及焊接方法等进行简要分析。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">澳大利亚液化天然气处理厂项目同时在中国、泰国、韩国、印度尼西亚、马来西亚</span>5<span style="font-family:宋体">个国家进行模块化建造,海洋石油工程(青岛)有限公司承建该项目中</span><span style="font-family:Calibri">172</span><span style="font-family:宋体">个模块,自身总质量约</span><span style="font-family:Calibri">4</span><span style="font-family:宋体">万</span><span style="font-family:Calibri">t</span><span style="font-family:宋体">,管线长约</span><span style="font-family:Calibri">150km</span><span style="font-family:宋体">,其中不锈钢工艺管线长约</span><span style="font-family:Calibri">40km</span><span style="font-family:宋体">,主要为管廊结构。整个工程项目的设计、建造和质量控制都按国际先进标准执行,如焊接设计、配管施工需要执行</span><span style="font-family:Calibri">ASME</span><span style="font-family:宋体">Ⅸ和</span><span style="font-family:Calibri">ASMEB31.3</span><span style="font-family:宋体">标准。</span></span></p><p><span style=";font-family:宋体;font-size:14px">1<span style="font-family:宋体">奥氏体不锈钢性能与应用</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">奥氏体不锈钢具有与低碳钢相当的强度,其塑韧性明显优于低碳钢。特别是在低温条件下,奥氏体不锈钢的塑韧性更为突出,基本不存在脆性转变,仅随温度的降低,冲击吸收功稍有降低,如</span>18-8<span style="font-family:宋体">型不锈钢在</span><span style="font-family:Calibri">-196</span><span style="font-family:宋体">℃时的冲击吸收功可达</span><span style="font-family:Calibri">392J</span><span style="font-family:宋体">。</span><span style="font-family:Calibri">304</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">316</span><span style="font-family:宋体">均为奥氏体不锈钢,它们的力学性能见表</span><span style="font-family:Calibri">1</span><span style="font-family:宋体">。</span><span style="font-family:Calibri">304</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">316</span><span style="font-family:宋体">是奥氏体不锈钢系列中最典型、最常用的钢种,不但强度高,而且低温冲击韧性好,可用于低温工作环境。这</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">种钢具有多数奥氏体不锈钢所具有的性能,在大多数环境中具有良好的耐腐蚀性及加工工艺性。</span><span style="font-family:Calibri">304/304L</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">316/316L</span><span style="font-family:宋体">不锈钢在澳大利亚液化天然气处理厂项目中用于模块底层和中层的超低温</span><span style="font-family:Calibri">LNG</span><span style="font-family:宋体">输送工艺管线,其模块典型图如图</span><span style="font-family:Calibri">1</span><span style="font-family:宋体">所示。</span></span></p><p><span style=";font-family:宋体;font-size:14px">2<span style="font-family:宋体">焊接性分析</span></span></p><p><span style=";font-family:宋体;font-size:14px">304/304L<span style="font-family:宋体">和</span><span style="font-family:Calibri">316/316L</span><span style="font-family:宋体">不锈钢与所有奥氏体不锈钢一样,与其他类型不锈钢相比,其焊接性较好,但是由于奥氏体不锈钢自身的一些特殊性能,如合金元素含量较高,导致在焊接时仍然会出现如下问题:</span></span></p><p><span style="font-family:宋体;font-size:14px">(1)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">焊接时,热裂纹倾向较大。</span></span></p><p><span style="font-family:宋体;font-size:14px">(2)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">焊接接头抗腐蚀性能降低,如果焊接材料选择不当,会造成焊缝的集中腐蚀。</span></span></p><p><span style="font-family:宋体;font-size:14px">(3)</span><span style=";font-family:宋体;font-size:14px">304<span style="font-family:宋体">和</span><span style="font-family:Calibri">316</span><span style="font-family:宋体">奥氏体不锈钢焊接时,焊缝中往往含有少量的铁素体,奥氏体不锈钢焊缝中的少量铁素体将使接头的低温韧性恶化,使接头发生低温脆化现象,而单一的奥氏体焊缝可以避免接头的低温脆化,同时奥氏体不锈钢焊缝中如果含有较多的铁素体化元素时,将发生显著的高温脆化现象。</span></span></p><p><span style=";font-family:宋体;font-size:14px">3<span style="font-family:宋体">焊接方法和焊接工艺</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">针对上述奥氏体不锈钢焊接时易出现的问题,主要从焊接材料的选择、焊接工艺方法选择方面予以预防和解决。笔者根据等合金含量原则选用焊接材料,经过查询相关技术资料和美国焊接学会标准</span>AWSA5.9<span style="font-family:宋体">和</span><span style="font-family:Calibri">AWSA5.22</span><span style="font-family:宋体">选择与</span><span style="font-family:Calibri">304</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">316</span><span style="font-family:宋体">不锈钢相应的焊接材料。</span><span style="font-family:Calibri">GORGON</span><span style="font-family:宋体">项目中不锈钢焊丝基本采用</span><span style="font-family:Calibri">GTS-308L</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">GFS-316L</span><span style="font-family:宋体">的氩弧焊丝,这</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">种焊丝直径为均</span><span style="font-family:Calibri">2.0mm</span><span style="font-family:宋体">,二氧化碳焊时采用</span><span style="font-family:Calibri">GFS-308L</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">TGS-316L</span><span style="font-family:宋体">的二氧化碳焊焊丝,这</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">种焊丝直径均为</span><span style="font-family:Calibri">1.2mm</span><span style="font-family:宋体">。焊接工艺参数见表</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">。</span></span></p><p><span style=";font-family:宋体;font-size:14px">3.1<span style="font-family:宋体">焊接方法</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">一般来说,</span>304<span style="font-family:宋体">和</span><span style="font-family:Calibri">316</span><span style="font-family:宋体">这样的奥氏体不锈钢几乎所有的熔化焊方法都可以采用,如焊条电弧焊、埋弧焊、钨极氩弧焊和药芯焊丝气体保护焊。对于大型结构件和管线焊接,熔化焊是可行且效益较高的焊接方法。但是,由于</span><span style="font-family:Calibri">304</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">316</span><span style="font-family:宋体">这</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">种奥氏体不锈钢的线膨胀系数较大,易使焊接变形较大,并且含有较多合金元素,有些合金元素很容易烧损。因此,在选择焊接方法时,要求其保护性好,焊接能量比较集中。传统焊接方法常选用钨极氩弧焊,其原因是钨极氩弧焊具有以下特点:</span></span></p><p><span style="font-family:宋体;font-size:14px">(1)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">惰性气体不与母材及焊材金属发生任何反应。</span></span></p><p><span style="font-family:宋体;font-size:14px">(2)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">焊接工艺性能好,明弧,便于观察电弧及熔池,填充焊丝是通过电弧间接加热,焊接过程无飞溅,焊缝成形美观,且焊接热输入小,特别适合薄板和薄壁管件的焊接。</span></span></p><p><span style="font-family:宋体;font-size:14px">(3)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">能进行全位置焊接,是实现单面焊双面成形的理想焊接方法,并能进行脉冲焊接,容易调节和控制焊接热输入,适合于薄板或对热敏感材料的焊接。但是,由于钨极氩弧焊熔深较浅,焊接速度慢,焊接生产率较低,惰性气体价格较高,使生产成本较高。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">为克服钨极氩弧焊的上述缺点,进一步提高生产效率,澳大利亚液化天然气处理厂项目不锈钢管线焊接通常采用钨极氩弧焊打底,焊条电弧焊和药芯焊丝气体保护焊进行填充、盖面的组合焊接方法,不但可以提高生产效率,而且可以提供很好的保护效果。</span></span></p><p><span style=";font-family:宋体;font-size:14px">3.2<span style="font-family:宋体">焊接工艺</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">奥氏体不锈钢焊接时需要注意的问题:</span></span></p><p><span style="font-family:宋体;font-size:14px">(1)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在奥氏体不锈钢焊接时,应尽可能地采用短弧焊接,这是由于:一方面其可现金麻将以减少或防止</span>Ti<span style="font-family:宋体">,</span><span style="font-family:Calibri">Nb</span><span style="font-family:宋体">,</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">,</span><span style="font-family:Calibri">Al</span><span style="font-family:宋体">等合金元素的烧损,另一方面还可以减少或防止飞溅。</span></span></p><p><span style="font-family:宋体;font-size:14px">(2)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">奥氏体不锈钢焊接时应尽可能地减少电弧的摆动,最好不要横向摆动,采用直通焊,焊接速度尽可能快些。</span></span></p><p><span style="font-family:宋体;font-size:14px">(3)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">奥氏体不锈钢焊接时不可随意引弧,特别要注意不可在焊件表面引弧,引弧时要有引弧板,熄弧时要有熄弧板。</span></span></p><p><span style="font-family:宋体;font-size:14px">(4)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">奥氏体不锈钢焊接时要仔细地清理坡口,保持表面光洁,每层焊缝清渣要彻底,清渣时不能用小铁锤乱敲乱打,要用小木锤或橡皮锤,用铜丝刷清渣,不可用钢丝刷清渣。</span></span></p><p><span style="font-family:宋体;font-size:14px">(5)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">必要时要采取强迫冷却措施,例如水冷方式,采用铜垫板等以降低道间温度。</span></span></p><p><span style="font-family:宋体;font-size:14px">(6)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">最后一道焊缝要尽可能安排在与腐蚀介质相接触的一面施焊。</span></span></p><p><span style="font-family:宋体;font-size:14px">(7)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">奥氏体<a href="http://fuxinfengshuo.top/" target="_self">不锈钢</a>焊接时,焊前不需要预热,因为奥氏体不锈钢的冷裂纹倾向极小,而且为防止晶粒粗化,要求提高冷却速度。</span></span></p><p><span style=";font-family:宋体;font-size:14px">4<span style="font-family:宋体">总结</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">正是因为奥氏体不锈钢具有强度高、塑韧性好、耐腐蚀性和较好的加工工艺性等显著优点,故在</span>GORGON<span style="font-family:宋体">项目中,较多地采用了这种材质作为工艺管线。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">针对奥氏体不锈钢的产生热裂纹等缺点,在澳大利亚液化天然气处理厂项目管线施工过程中常采用氩弧焊打底、焊条电弧焊和药芯焊丝气体保护焊填充、盖面的组合焊接方法,既可以满足项目对焊接质量等方面的施工需求,又大大提高了生产效率,该焊接方法在澳大利亚液化天然气处理厂项目施工中得到了很好的应用。</span></span></p> Wed, 12 Dec 2018 23:54:16 +0800 耐热不锈钢310S的高温氧化性能 http://fuxinfengshuo.top/post/124.html <p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">利用增重法研究了耐热不锈钢310S在空气中800、900、1000</span>℃下的高温氧化行为,绘制了氧化动力学曲线。利用SEM、XRD、EDS对氧化膜的结构及分布进行了表征。结果表明:800、900、1000℃下的氧化动力学曲线符合抛物线规律,具有优异的抗氧化性。氧化膜由致密的MnCr2O4、Cr2O3和内层SiO2组成,3层氧化膜是其抗氧化性能优异的主要原因。</span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">高温抗氧化性能作为耐热钢的一个重要性能指标,已经被众多研究者关注。钢中特殊合金元素是改善和提高合金抗氧化性能的重要原因,在保证基本性能的前提,合适地加入合金元素是改善和提高合金抗氧化性能的重要原因,在保证基本性能的前提下,合适地加入合金元素能在钢表面形成不同的致密氧化膜,从而提高其高温抗氧化性。耐热不锈钢310S是高铬高镍奥氏体不锈钢,其不仅具有优良的耐蚀、力学性能,同时也具有优异的高温耐氧化性、抗蠕变性。因此,被广泛应用在各种高温炉、特殊环境的高温部件等。关于<a href="http://fuxinfengshuo.top/" target="_self">耐热不锈钢310S</a>的高温氧化机制,目前已经有了研究。杨照明等作了氧化动力学分析和表面生成物的研究,但对表面氧化膜的构成、分布及形成机制没有深入探讨。本文通过研究310S在空气中的高温氧化试验来评定其高温氧化性能,在分析氧化动力学增重曲线的基础上,研究其氧化膜的形貌、分布、结构,并对其形成机制进行了解释。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">1试验</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">试验样品取自太钢奥氏体耐热不锈钢310S热板,化学成分见表1。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">样品切割成30mm</span>×15mm×4mm,每个试验点使用3个平行样,对试样进行研磨,经水砂纸打磨除去表面氧化皮及线切割加工痕迹,然后用乙醇清洗吹干。准备与试样相同数量的坩埚,对坩埚进行编号,用电阻加热炉对其进行烘烤,使坩锅中的残留物质充分挥发,质量恒定。将高温氧化的试样直接置于坩埚中,一同放在箱式电阻炉中进行高温氧化。试验气氛为空气,氧化温度分别为800、900、1000℃;每个试样处理时间分别为20、40、60、80、100、120、140h。氧化完成后称重并记录,称重仪器为电子分析天平。高温氧化试验结束后,用X射线衍射仪对氧化产物进行物相分析,用扫描电子显微镜(SEM)、能谱仪(EDS)分析氧化膜的表面形貌。</span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">2结果与分析</span></span></p><p><span style="font-family:宋体;font-size:14px">2.</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">1氧化动力学</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">图1是试样在800、900、1000</span>℃空气中氧化的动力学曲线及Δm2与时间t的关系曲线。由图1(a)可知,氧化增重随温度的升高而增加,当温度为800℃时,氧化增重最小,其平均增重为0.12mg/(cm2·h);在900和1000℃时,增重增加随着温度增加,平均增重分别达到了0.44和0.68mg/(cm2·h);各温度下随着时间的延长,均有不同程度氧化增重的趋势,但随着时间延长氧化趋势减缓。对数据作Δm2与t的关系曲线如图1(b)所示,两者基本呈现直线关系,可以判断该合金氧化曲线遵循抛物线规律。</span></p><p><span style="font-family:宋体;font-size:14px">2.</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">2氧化膜的表面形貌</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">图2是耐热不锈钢310S不同温度氧化不同时间后的表面SEM图片。可以看出,800</span>℃氧化140h后,表面覆盖一层致密的氧化物,氧化物由多数未长大的尖晶石颗粒和很少量的片状结构构成。能谱分析表明,尖晶石颗粒主要由元素铬、氧、锰组成,片状结构由铬、氧组成,说明尖晶石颗粒可能为铬、锰的氧化物,片状结构为铬的氧化物。当温度升高到900℃时,氧化20h,表面也出现两种形貌,与800℃形貌相似。随着时间的延长,当氧化到140h时,表面全部为尖晶石结构,其晶粒尺寸随时间延长而增大。随着温度升高到1000℃,部分尖晶石结构长大,出现如图2(d)的形貌。</span></p><p><span style="font-family:宋体;font-size:14px">2.</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">3氧化膜的结构</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">图3是耐热不锈钢310S在800、900、1000</span>℃下高温氧化140h后的XRD图谱。根据衍射峰的位置可以判断出,在3个温度下生成的氧化膜主要成分都为Cr2O3和MnCr2O4。这与样品表面氧化膜的能谱分析一致,说明片状结构为Cr2O3,尖晶石颗粒为MnCr2O4。同时,从图上可以看出,随着温度的升高,基体的峰变弱,说明氧化膜厚度随着温度增加而增加,但基体的峰位未消失,说明氧化膜还比较薄,这主要是因为高温下表面生成了致密的Cr2O3和MnCr2O4膜,阻碍了氧和金属离子的相互扩散,使得抗氧化性能提高。相反,MnCr2O4的峰随着温度的升高变强,说明在高温下产生了更多的尖晶石结构MnCr2O4。</span></p><p><span style="font-family:宋体;font-size:14px">2.</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">4氧化膜横截面元素分布</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">为了确认氧化物在氧化层的分布情况,对其断面进行了能谱面扫描。从图4上可以看出,氧化层分为3层,锰、铬、氧分布在最外层,结合XRD数据结果,最外层是锰的尖晶石结构MnCr2O4;中间层是铬和氧及少量的锰,所以中间层为Cr2O3和Mn-Cr2O4;最里面一层分布着连续的硅,所以里面是一层硅的氧化物。</span></span></p><p><span style="font-family:宋体;font-size:14px">2.</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">5分析</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">根据埃林厄姆-理查森图,从热力学上优先生成SiO2,其次为MnO、Cr2O3、铁和镍的氧化物。但是氧化的过程不仅要考虑热力学,还要考虑动力学。由于基体铬元素质量分数很高,当样品置于高温环境下时,刚开始反应主要是表面的铬吸附空气中的氧反应,所以这一阶段反应速度很快,表面快速氧化形成了一层Cr2O3。随着反应的进行,铬优先通过晶界的扩散(晶界能高,是快速扩散的最佳通道)到达表面,在表面持续形成片状Cr2O3的薄膜。随着反应的进一步进行,由于铬从内向外扩散,导致了内层的贫铬,当铬的浓度达到临界值时,锰开始通过晶界向外扩散,与氧发生反应形成MnO或者Mn2O3,锰的氧化物与铬的氧化物复合,在外面形成了尖晶石颗粒MnCr2O4。这一过程是由扩散控制,其氧化动力学符合抛物线规律。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">而硅的氧化物主要是由于内层氧化引起的。硅的氧化物自由能相对于氧化铁更低,且在低氧压下更容易形成。氧通过扩散进入薄膜内,在金属和氧化物界面处与硅反应发生内层氧化,在氧化薄膜内层生成了一层连续的氧化硅层。硅的氧化物之所以在XRD及表面能谱上反映不出来,可能是由于硅的氧化物质量分数少,且在氧化物最里层,信号采集不到导致的。3层致密的结构加上氧化物本身的良好抗氧化性能,从而使耐热不锈钢310S整体表现出很好的抗高温氧化性。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">3结论</span></span></p><p><span style="font-family:宋体;font-size:14px">(1)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">耐热不锈钢310S在800、900、1000</span>℃下表现出很好的抗氧化性。各温度下随着时间的延长,均有不同程度氧化增重的趋势,但随着时间延长氧化趋势减缓。同时随着温度的升高,氧化速率增快。</span></p><p><span style="font-family:宋体;font-size:14px">(2)</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">氧化膜由外层致密的尖晶石MnCr2O4、Cr2O3和内层的SiO2组成,随温度升高,MnCr2O4衍射峰增强,生成物增多。3层致密的氧化物使其具有优异的抗高温氧化性能。</span></span></p> Wed, 10 Oct 2018 20:48:56 +0800 不锈钢管对国民经济和人类生活的重要意义 http://fuxinfengshuo.top/post/123.html <p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">工业的发展开始于自行车制造业的兴起。十九世纪初期石油的开发,两次世界大战期间舰船、锅炉和飞机的制造,第二次世界大战后火电锅炉的制造,化学工业的发展以及石油、天然气的钻采和输送等,部有力地推动将</span></span><a href="http://fuxinfengshuo.top/" target="_self"><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span></a><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">工业在品种、质量和产量上的发展。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不仅能用于输送流体和粉状固体、交换热能、制造机器零件和容器,它还是一种能节约金属的经济钢材,用</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">制作建筑结构和机械支架,可以节省金属,减轻重量,用</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">代替槽钢可以节省钢材</span></span><span style=";font-family:宋体;font-size:14px">60%</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">左右。例如,建造一幢</span></span><span style=";font-family:宋体;font-size:14px">50000m3</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的楼房,用</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">结构只需</span></span><span style=";font-family:宋体;font-size:14px">200</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">吨,而用型钢则不少于</span></span><span style=";font-family:宋体;font-size:14px">350-400</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">吨。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">与人类生活关系的密切胜于其它轧制钢材,从自行车、日用家俱、供水供气设备,到各种工农机具的制造,地下资源的开发,国防和航天技术所用导弹、火箭等等,都离不开</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">由于</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">对国民经济和人类生活关系甚大,所以</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">生产不仅发展迅速,而且在钢铁工业中的地位也日益提高。全世界</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">产量在钢材总产量中所占比重正在不断增加。</span></span></p> Sat, 22 Sep 2018 21:33:59 +0800 2520不锈钢管冷却技术的发展概况 http://fuxinfengshuo.top/post/122.html <p><span style=";font-family:宋体;font-size:14px">&nbsp; &nbsp;<span style="font-family:宋体">控制轧制与控制冷却是</span>20<span style="font-family:宋体">世纪</span><span style="font-family:Calibri">50</span><span style="font-family:宋体">年代在欧洲为生产高韧性造船用钢板而诞生的轧制技术。目前,板带材生产中控制冷却技术的应用十分广泛,在高强度钢的生产过程中,产品碳当量、合金元素含量降低,韧性、焊接性能提高,凸显了控制冷却技术在钢材生产中的重要性。近年来,加强型冷却装置</span><span style="font-family:Calibri">(ILC</span><span style="font-family:宋体">,</span><span style="font-family:Calibri">IntensiveLaminar Cooling)</span><span style="font-family:宋体">或超快速冷却装置</span><span style="font-family:Calibri">(UFC</span><span style="font-family:宋体">,</span><span style="font-family:Calibri">Ultra Fast Cooling)</span><span style="font-family:宋体">与传统冷却方式的配合使用,为超细晶粒钢、双相钢、相变诱导塑性钢</span><span style="font-family:Calibri">(TRIP</span><span style="font-family:宋体">钢</span><span style="font-family:Calibri">)</span><span style="font-family:宋体">、铁素体区热轧无间隙原子钢等高附加值产品的生产提供了更有效的途径。</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-family:宋体">在</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">生产领域中,由于热轧</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">生产机组的复杂性和多样性,产品外形特点和其尺寸规格的多样性,以及热轧</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">生产过程中的变形温度、变形量、冷却温度及冷却速度等参数对</span></span><a href="http://fuxinfengshuo.top/" target="_self"><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span></a><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">组织性能变化规律的影响的研究还比较缺乏,目前热轧</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的控制轧制控制冷却工艺的应用与板带材及棒线材相比还很少。现将当前</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">领域中的控制冷却技术的研究和发展状况简单的归纳如下</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">。</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;(1)<span style="font-family:宋体">控轧控冷技术已较广泛的应用于板带材产品中,而</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">及型钢类产品由于其产品形状复杂,品种规格多样,很少被应用。热轧板、带材断面形状简单、冷却装置设计较方便,冷却理论和技术发展较成熟,现在层流和水幕冷却在此类热轧控冷生产中应用的十分广泛。特别是薄板带材产品厚度尺寸小,冷却技术比较完善,产品整体可实现整体超快冷却,并可较精确控制其冷却过程中的温度和卷曲温度,已成为提高产品质量的重要手段,另外运用不同的冷却策略,可以生产多种类型的高附加值产品。这些都将是</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">控制冷却技术发展中重要的借鉴和参考资料;</span> </span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;(2)<span style="font-family:宋体">现有</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">生产多采用空冷或空冷加冷床上风冷的冷却方式,产品以低中档为主,且此类产品市场逐渐趋于饱和,而高质量产品市场需求较大,进口量较多;</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;(3)<span style="font-family:宋体">.高档次</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">类产品生产,大都需要进行后续热处理,而传统的离线热处理工艺复杂,能量消耗大,生产周期长。为降低成本,提高生产效率,在线热处理技术逐渐开始运用,并在不断重视和发展;</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;(4)</span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的在线热处理工艺技术逐渐得到重视,主要表现如下:目前石油管等生产中较多应用了在线常化工艺技术,日本和歌山制铁所已成功将在线淬火工艺应用于该厂</span>90%<span style="font-family:宋体">的适用热处理工艺的产品,天津钢管集团</span><span style="font-family:Calibri">ASSEL</span><span style="font-family:宋体">轧管生产线设计并投入了一套在线加速冷却系统,</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">企业正在不断努力提高自身热处理工艺水平和生产效率;</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;</span><span style=";font-family:宋体;font-size:14px">&nbsp;</span><span style=";font-family:宋体;font-size:14px">&nbsp;(5)</span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">生产的自动化水平不断提高,控制冷却系统的高效自动化控制已是现代</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">生产中冷却技术发展的必然选择</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">。</span></span></p> Thu, 20 Sep 2018 22:41:07 +0800 2520不锈钢管中合金元素的作用 http://fuxinfengshuo.top/post/121.html <p><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">中的主要元素有</span>Cr<span style="font-family:宋体">、</span><span style="font-family:Calibri">Ni</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">Mn</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">Si</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">C</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">等,各元素的主要作用阐述如下,由于</span><span style="font-family:Calibri">Nb</span><span style="font-family:宋体">元素在</span><span style="font-family:Calibri">310S</span><span style="font-family:宋体">钢中的作用是本文主要研究对象,因此单独对其阐述。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">(</span>1<span style="font-family:宋体">)</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">元素</span></span></p><p><span style=";font-family:宋体;font-size:14px">Cr<span style="font-family:宋体">元素是</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的主要合金元素,为了提高</span></span><a href="http://fuxinfengshuo.top/" target="_self"><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span></a><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在高温应用下的抗氧化性,其</span>Cr<span style="font-family:宋体">含量一般控制在</span><span style="font-family:Calibri">25%</span><span style="font-family:宋体">左右。</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">是铁素体形成元素,过多的</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">元素会导致铸造、焊接过程中生成δ</span><span style="font-family:Calibri">-</span><span style="font-family:宋体">铁素体,无法得到全奥氏体组织。同时,</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">会促进</span><span style="font-family:Calibri">M23C6</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">Cr2N</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">Z</span><span style="font-family:宋体">相的析出,</span><span style="font-family:Calibri">M23C6</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">Cr2N</span><span style="font-family:宋体">会在晶界形成膜状结构,不但降低合金的韧脆性,而且会导致晶界贫</span><span style="font-family:Calibri">Cr</span><span style="font-family:宋体">,从而增大不锈钢的晶间腐蚀的敏感性</span><span style="font-family:Calibri">[22]</span><span style="font-family:宋体">。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">(</span>2<span style="font-family:宋体">)</span><span style="font-family:Calibri">Ni</span><span style="font-family:宋体">元素</span></span></p><p><span style=";font-family:宋体;font-size:14px">Ni<span style="font-family:宋体">元素是奥氏体稳定化元素,为了得到全奥氏体组织,一般加入</span><span style="font-family:Calibri">20%</span><span style="font-family:宋体">左右的</span><span style="font-family:Calibri">Ni</span><span style="font-family:宋体">元素。</span><span style="font-family:Calibri">Ni</span><span style="font-family:宋体">还可以提高不锈钢表面膜的稳定性,进而提高不锈钢的抗腐蚀性能。有研究表明,在</span><span style="font-family:Calibri">20-25Cr</span><span style="font-family:宋体">钢中加入</span><span style="font-family:Calibri">20wt.%</span><span style="font-family:宋体">的</span><span style="font-family:Calibri">Ni</span><span style="font-family:宋体">最为合适。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">(</span>3<span style="font-family:宋体">)</span><span style="font-family:Calibri">Mn</span><span style="font-family:宋体">元素</span></span></p><p><span style=";font-family:宋体;font-size:14px">Mn<span style="font-family:宋体">元素也是奥氏体稳定化元素,</span><span style="font-family:Calibri">Ni</span><span style="font-family:宋体">元素价格较高,为了降低生产成本,现在很多钢种通过加入</span><span style="font-family:Calibri">Mn</span><span style="font-family:宋体">来代替</span><span style="font-family:Calibri">Ni</span><span style="font-family:宋体">元素。此外,</span><span style="font-family:Calibri">Mn</span><span style="font-family:宋体">可以提高</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">在奥氏体中的固溶度。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">(</span>4<span style="font-family:宋体">)</span><span style="font-family:Calibri">C</span><span style="font-family:宋体">元素</span></span></p><p><span style=";font-family:宋体;font-size:14px">C<span style="font-family:宋体">是间隙型原子,其固溶强化效果仅次于</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">元素,并且适量的</span><span style="font-family:Calibri">C</span><span style="font-family:宋体">能与</span><span style="font-family:Calibri">Nb</span><span style="font-family:宋体">和</span><span style="font-family:Calibri">V</span><span style="font-family:宋体">等元素形成</span><span style="font-family:Calibri">MC</span><span style="font-family:宋体">型碳化物,这些碳化物弥散分布在基体上,对晶粒起钉扎作用,能够抑制晶粒长大</span><span style="font-family:Calibri">[24]</span><span style="font-family:宋体">,但是加入过量的</span><span style="font-family:Calibri">C</span><span style="font-family:宋体">会导致大尺寸的</span><span style="font-family:Calibri">MC</span><span style="font-family:宋体">从液相中析出(一次</span><span style="font-family:Calibri">MC</span><span style="font-family:宋体">相),这些一次</span><span style="font-family:Calibri">MC</span><span style="font-family:宋体">一般在晶界处析出,降低了合金的韧塑性;同时大量</span><span style="font-family:Calibri">C</span><span style="font-family:宋体">元素的加入会促进</span><span style="font-family:Calibri">M23C6</span><span style="font-family:宋体">的大量析出,导致材料抗腐蚀性能和韧性下降。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">(</span>5<span style="font-family:宋体">)</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">元素</span></span></p><p><span style=";font-family:宋体;font-size:14px">N<span style="font-family:宋体">元素是奥氏体化元素,其间隙固溶强化作用最强。</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在长时间时效后有</span>sigma<span style="font-family:宋体">相生成,</span><span style="font-family:Calibri">Rolf Sandstr?m </span><span style="font-family:宋体">等人通过对不同</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">含量的</span></span><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的金相的观察及热力学计算发现</span>N<span style="font-family:宋体">能够抑制</span><span style="font-family:Calibri">sigma</span><span style="font-family:宋体">相的生成。</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">能够促进</span><span style="font-family:Calibri">Z</span><span style="font-family:宋体">相的生成,在长时间时效下,例如</span><span style="font-family:Calibri">HR3C</span><span style="font-family:宋体">在</span><span style="font-family:Calibri">750</span><span style="font-family:宋体">℃时效</span><span style="font-family:Calibri">500h</span><span style="font-family:宋体">后会析出</span><span style="font-family:Calibri">Z</span><span style="font-family:宋体">相。在</span><span style="font-family:Calibri">9-12Cr%</span><span style="font-family:宋体">钢中,</span><span style="font-family:Calibri">Z</span><span style="font-family:宋体">相会降低材料的高温(</span><span style="font-family:Calibri">700</span><span style="font-family:宋体">℃)韧性,目前</span><span style="font-family:Calibri">Z</span><span style="font-family:宋体">相对奥氏体不锈钢作用还不明确。高</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">不锈钢在焊接中会产生氮化物,降低焊接性能。</span></span></p><p><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">(</span>6<span style="font-family:宋体">)</span><span style="font-family:Calibri">V</span><span style="font-family:宋体">元素</span></span></p><p><span style=";font-family:宋体;font-size:14px">2520<span style="font-family:宋体">不锈钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">中不含</span>V<span style="font-family:宋体">元素,但微合金钢中常常使用</span><span style="font-family:Calibri">V</span><span style="font-family:宋体">作为微合金化主要元素</span><span style="font-family:宋体">,与其它微合金相比,</span><span style="font-family:Calibri">V</span><span style="font-family:宋体">元素在</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃以上时有较高的固溶度</span><span style="font-family:Calibri">[29]</span><span style="font-family:宋体">,因此含</span><span style="font-family:Calibri">V</span><span style="font-family:宋体">的析出相主要在</span><span style="font-family:Calibri">800</span><span style="font-family:宋体">℃以下起强化作用。</span><span style="font-family:Calibri">VN</span><span style="font-family:宋体">在奥氏体和铁素体中固溶都比</span><span style="font-family:Calibri">VC</span><span style="font-family:宋体">低很多,热力学计算和实验都表明</span><span style="font-family:Calibri">VN</span><span style="font-family:宋体">先于</span><span style="font-family:Calibri">VC</span><span style="font-family:宋体">析出。</span><span style="font-family:Calibri">V(C,N)</span><span style="font-family:宋体">析出物一般会在</span><span style="font-family:Calibri">700</span><span style="font-family:宋体">℃左右的温度区间析出。细小弥散的</span><span style="font-family:Calibri">V(C,N)</span><span style="font-family:宋体">会钉扎在晶界和晶内,提高材料强度。此外,</span><span style="font-family:Calibri">V</span><span style="font-family:宋体">会固定</span><span style="font-family:Calibri">N</span><span style="font-family:宋体">元素,改善焊接性能。</span></span></p> Mon, 17 Sep 2018 17:14:33 +0800 不锈耐热钢管的生产 http://fuxinfengshuo.top/post/120.html <p><span style=";font-family:宋体;font-size:14px">&nbsp; &nbsp;&nbsp;<span style="font-family:宋体">在空气、水、碱、酸以及其他介质中具有抗腐蚀能力的钢称为不锈钢,而专门用于抗酸浸蚀的钢则称为耐酸钢,在高温下具有足够的机械性能而且也有抗腐蚀能力的钢称为耐热钢。</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-family:宋体">要把不锈</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">、</span></span><a href="http://fuxinfengshuo.top/" target="_self"><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">耐热</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span></a><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">及耐酸</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在用途上节然分开是难的,例如</span>1Cr18Ni9Ti<span style="font-family:宋体">不锈</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">在</span>500-600<span style="font-family:宋体">℃具有耐热性,同时也具有抗酸能力。这种</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">还具有无碘和不生锈特性,也具有良好的机械性能和工艺性能,因此</span>1Cr18Ni9Ti<span style="font-family:宋体">不锈钢管被广泛地应用于各种工业部门和国防部门中。</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;<span style="font-family:宋体">这些</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">中的合金元素依具体工作条件而定,按照不锈</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">的成分和组织特点,用于钢管生产的可分为下列三类:</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;1)<span style="font-family:宋体">马氏体型不锈</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">,含有</span>12~18%Cr<span style="font-family:宋体">及</span><span style="font-family:Calibri">0.1~0.4%C(</span><span style="font-family:宋体">个别达</span><span style="font-family:Calibri">1.0%)</span><span style="font-family:宋体">,可淬水成马氏体(如</span><span style="font-family:Calibri">3Cr13</span><span style="font-family:宋体">,</span><span style="font-family:Calibri">4Cr13 - Cr18</span><span style="font-family:宋体">等)和十马氏体(含有铁素体,如</span></span><span style=";font-family:宋体;font-size:14px">1</span><span style=";font-family:宋体;font-size:14px">Cr13<span style="font-family:宋体">,</span><span style="font-family:Calibri">2Cr13</span><span style="font-family:宋体">等)。</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;2)<span style="font-family:宋体">铁素体型不锈</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">,含有</span>17</span><span style=";font-family:宋体;font-size:14px">-</span><span style=";font-family:宋体;font-size:14px">30%Cr<span style="font-family:宋体">及微量的碳,组织基本为铁素体(如</span><span style="font-family:Calibri">Cr25, Cr27, Cr28, Cr25Ti</span><span style="font-family:宋体">等)。</span></span></p><p><span style=";font-family:宋体;font-size:14px">&nbsp;&nbsp;&nbsp;&nbsp;3)<span style="font-family:宋体">奥氏体型不锈</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">钢管</span></span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">,含有</span>12<span style="font-family:宋体">~</span><span style="font-family:Calibri">30%Cr</span><span style="font-family:宋体">、</span><span style="font-family:Calibri">6~12%Ni</span><span style="font-family:宋体">以及</span><span style="font-family:Calibri">Mn</span><span style="font-family:宋体">等,合碳量≤</span><span style="font-family:Calibri">0</span></span><span style=";font-family:宋体;font-size:14px">.</span><span style=";font-family:宋体;font-size:14px">2%<span style="font-family:宋体">,组织基本为奥氏体(如</span><span style="font-family:Calibri">0Cr18Ni9</span><span style="font-family:宋体">,</span><span style="font-family:Calibri">1Cr18Ni</span></span><span style=";font-family:宋体;font-size:14px">9</span><span style=";font-family:宋体;font-size:14px"><span style="font-family:宋体">,</span>1Cr18Ni</span><span style=";font-family:宋体;font-size:14px">9</span><span style=";font-family:宋体;font-size:14px">Ti<span style="font-family:宋体">,</span><span style="font-family:Calibri">Cr18Ni10Ti</span><span style="font-family:宋体">等)。</span></span></p> Sat, 15 Sep 2018 18:30:40 +0800 310S不锈钢管焊接接头的分析 http://fuxinfengshuo.top/post/119.html <p><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px">310S<span style="font-family:宋体">不锈钢管</span></span><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px"><span style="font-family:宋体">是以热轧状态供货的钢板。该钢的耐蚀性能优于碳钢,是目前比较好的油罐用钢。</span></span></p><p><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px"><span style="font-family:宋体">焊接</span></span><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px">310S<span style="font-family:宋体">不锈钢管</span></span><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px"><span style="font-family:宋体">用的焊条,是含有硅、铝、钒等抗腐蚀元素的低氢型焊条,具有良好的工艺性能。钢材、焊缝和焊条的化学成分、机械性能分别列于表</span>11-2<span style="font-family:宋体">和表</span><span style="font-family:Calibri">11-3</span><span style="font-family:宋体">。</span></span></p><p><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px">310S<span style="font-family:宋体">不锈钢管</span></span><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px"><span style="font-family:宋体">,由于其含铝量较低(仅为</span>0.2<span style="font-family:宋体">~</span><span style="font-family:Calibri">0.3%</span><span style="font-family:宋体">),因此熔合线处的铁素体晶粒长大倾向很小,对接头的机械性能几乎没有什么影响。接头的塑性和韧性很高,所有冷弯试样都达到</span><span style="font-family:Calibri">180</span><span style="font-family:宋体">度不裂,熔合线的冲击值都在</span><span style="font-family:Calibri">14</span><span style="font-family:宋体">公斤·米/厘米</span><span style="font-family:Calibri">2</span><span style="font-family:宋体">以上。钢材和焊条的抗裂性能良好。板厚为</span><span style="font-family:Calibri">12</span><span style="font-family:宋体">毫米,采用</span><span style="font-family:Calibri">4</span><span style="font-family:宋体">毫米直径焊条,通过小铁研式和双</span><span style="font-family:Calibri">T</span><span style="font-family:宋体">型接头抗裂试验,没有发现裂纹。</span></span></p><p><a href="http://fuxinfengshuo.top/bxgcl/" target="_self"><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px">310S<span style="font-family:宋体">不锈钢管</span></span></a><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px"><span style="font-family:宋体">的焊接接头,通过在含高硫原油罐上的挂片试验证明,焊接接头具有良好的抗硫油腐蚀性能。经</span>224<span style="font-family:宋体">天,整个焊接接头呈均匀瘸蚀。焊缝金属因含有较高的硅,其耐蚀能力优于钢材,焊缝比钢材表面光整致密。</span></span></p><p><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px"><span style="font-family:宋体">总之,</span></span><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px">310S<span style="font-family:宋体">不锈钢管</span></span><span style="font-family: 宋体;letter-spacing: 0;font-size: 14px"><span style="font-family:宋体">具有良好的可焊性,焊接时没确</span>+<span style="font-family:宋体">什么特殊要求。经实际油罐制造表明,这种钢可按</span><span style="font-family:Calibri">1 6</span><span style="font-family:宋体">锰钢相同的焊接工艺施焊。某些厂采用此钢制造了原油罐和再生塔等设备。</span></span></p> Fri, 14 Sep 2018 06:44:34 +0800