西安双相不锈钢管的焊接要求

摘要：<span style="font-family:宋體(tǐ);font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">西安双相不锈钢管的焊接要求</span></span> </p> <span style="font-family:宋體(tǐ);font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">在石油化工装置中一种新(xīn)型钢材</span><span style="font-family:'Times New Roman';"><span lang="EN-US">-</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">双相不锈钢的应用(yòng)越来越多(duō)。因為(wèi)双相不锈钢的屈服强度是普通不锈钢的</span><span style="font-family:'Times New Roman';"><span lang="EN-US">2</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">倍，抗腐蚀性能(néng)（特别是在腐蚀性介质中）明显优于普通不锈钢，在石油化工装置施工中多(duō)用(yòng)在很(hěn)重要的位置。因此，一般双相不锈钢的焊缝要求</span><span style="font-family:'Times New Roman';"><span lang="EN-US">100%RT</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">检验，对其焊接接头的综合性能(néng)的要求也高于一般奥氏體(tǐ)不锈钢。所以，必须选派焊接经验丰富的奥氏體(tǐ)不锈钢焊工，经培训和考试合格后，才能(néng)持证上岗进行焊接作业。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 1&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">焊接性分(fēn)析</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">双相不锈钢焊接时，焊接热影响區(qū)（</span><span style="font-family:'Times New Roman';"><span lang="EN-US">HAZ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">）</span></span><span style="font-family:'Times New Roman';font-size:small;"> </span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">存在高温區(qū)和低温區(qū)，低温區(qū)基本处于</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ+γ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">（铁素體(tǐ)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">+</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">奥氏體(tǐ)）平衡组织，而高温區(qū)几乎為(wèi)单相</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">组织，因為(wèi)焊缝根部和表面</span><span style="font-family:'Times New Roman';"><span lang="EN-US">N</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">的扩散，导致靠近焊缝表面的部位，由于</span><span style="font-family:'Times New Roman';"><span lang="EN-US">N</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">的损失，铁素體(tǐ)增加，从而促进氮化物(wù)的产生，使焊接接头性能(néng)恶化，焊接采用(yòng)高線(xiàn)能(néng)量时，可(kě)以得到较多(duō)的</span><span style="font-family:'Times New Roman';"><span lang="EN-US">γ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相，铁素體(tǐ)含量低会促进</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相产生，所以容易产生</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相和粗晶组织；線(xiàn)能(néng)量较低时，得不到足够的</span><span style="font-family:'Times New Roman';"><span lang="EN-US">γ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相。如果焊接金属中</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相过多(duō)，</span><span style="font-family:'Times New Roman';"><span lang="EN-US">N</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">很(hěn)容易与</span><span style="font-family:'Times New Roman';"><span lang="EN-US">cγ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">形成化合物(wù)，而且析出二次</span><span style="font-family:'Times New Roman';"><span lang="EN-US">γ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">变為(wèi)针状和羽毛状，具有(yǒu)魏氏體(tǐ)组织特性，导致焊接接头力學(xué)性能(néng)和耐腐蚀性下降。双相钢一般不会产生</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相，但如果焊接線(xiàn)能(néng)量较高，导致使焊接头塑性大幅度下降。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">焊接工艺</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.1&nbsp; &nbsp; </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">工艺参数及電(diàn)特性（见表</span><span style="font-family:'Times New Roman';"><span lang="EN-US">2</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">）</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.2&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">焊接方法</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">双相不锈钢薄壁管全部采用(yòng)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">GTAW</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">焊接，直流正极性。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.3&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">焊接设备</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">焊机采用(yòng)高频引弧焊机，直流正极性，钨极直径</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Φ2.5mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，钨极端头用(yòng)磨光机磨出锥形，采用(yòng)大喷嘴。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.4&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">气體(tǐ)保护</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">焊接保护气體(tǐ)采用(yòng)混合气體(tǐ)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Ar97.5%+N2.5% </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">进行保护，保护气采用(yòng)成品混合气，要求生产的成品混合比為(wèi)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Ar97.5%+N2.5%</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，由于混合气體(tǐ)中</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Ar</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">比</span><span style="font-family:'Times New Roman';"><span lang="EN-US">N</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">多(duō)，放置一段时间后将会产生分(fēn)层，影响气體(tǐ)保护效果，现场所采用(yòng)摇勺或加气體(tǐ)分(fēn)配器进行配比，确保气體(tǐ)保护质量。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.5&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">环境要求</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">双相不锈钢焊接要求环境清洁。无铁离子污染，预置工作将在室内进行，地面采用(yòng)胶皮隔离、安装必须做好环境保护。采用(yòng)防风防尘设施，环境温度</span><span style="font-family:'Times New Roman';"><span lang="EN-US">70</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">℃，相对温度</span><span style="font-family:'Times New Roman';"><span lang="EN-US">≤90%</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，所有(yǒu)与双相钢焊接坡口相接触的，如：焊材、工具、手套等，都必须无铁锈污染。坡口均采用(yòng)坡口机加工，坡口角度為(wèi)单边</span><span style="font-family:'Times New Roman';"><span lang="EN-US">30°±2.5°</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，钝边</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0~ 0.5mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，单面坡口（见附图），加工坡口不允许母材产生过烧变色；其两侧各</span><span style="font-family:'Times New Roman';"><span lang="EN-US">50mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以内的内外表面要进行严格清理(lǐ)，清理(lǐ)程序是磨光机打磨、丙酮（或无水乙醇）清洗，清洗后不能(néng)直接进行焊接作业，待坡口端面晾干后方可(kě)焊接作业；焊丝也用(yòng)沾丙酮（或无水乙醇）的海绵擦拭干净。对铁离子、水锈、油、灰尘、油漆、记号筆(bǐ)印都必须清理(lǐ)干净，防止其影响化學(xué)成份和机械性能(néng)。另外，还要注意坡口形状必须无凹凸和划痕，这样焊接时電(diàn)弧在焊道的每一点上都能(néng)保证停留相同的时间，焊接線(xiàn)能(néng)量才能(néng)确保一致。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.6&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">焊接措施</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">尽量采用(yòng)多(duō)层焊，因為(wèi)后续焊道对前层焊道有(yǒu)热处理(lǐ)作用(yòng)，焊缝中的</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相进一步转化為(wèi)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">γ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相，使焊接接头的组织和性能(néng)显著改善，而后一道焊缝处于非工作介质面，因為(wèi)对焊接接头影响不大，保护气采用(yòng)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Ar97.5%+N2.5%</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">。因為(wèi)焊接根部保护气體(tǐ)中加氮气增加焊缝金属氮量，由于采用(yòng)多(duō)层焊工艺，焊接材料中含</span><span style="font-family:'Times New Roman';"><span lang="EN-US">N</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">量与母材相当，而后一道焊缝处于非工作介质面，因為(wèi)对焊接接头影响不大，采用(yòng)合适的線(xiàn)能(néng)量焊接，使焊接接头得到足够的</span><span style="font-family:'Times New Roman';"><span lang="EN-US">γ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相，使</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Cγ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">、</span><span style="font-family:'Times New Roman';"><span lang="EN-US">N1 </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">和</span><span style="font-family:'Times New Roman';"><span lang="EN-US">M</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">有(yǒu)足够的时间扩散。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.7&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">坡口的组对及点焊</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">坡口组对前应仔细检查坡口管径是否相同，错边应控制在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0.5~1mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">之间，并用(yòng)磨光机打磨清理(lǐ)坡口及坡口正反面两侧</span><span style="font-family:'Times New Roman';"><span lang="EN-US">50mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以内的表面，并用(yòng)丙酮擦试干净，坡口打磨时不允许使母材产生过热变色。点焊时，应采用(yòng)与正式的焊接工艺相同的参数，点焊長(cháng)度為(wèi)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">7~8mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，高度為(wèi)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">2~ 3mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，点焊点应為(wèi)过桥型式，不应焊透，以防内部氧化，点焊電(diàn)流不宜过大，点焊点位置应在组对管子的上部及两侧，点固三点，从第四点起焊，当焊到点焊时，将点固点打磨清理(lǐ)干净，焊缝组对间隙应控制在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">2~2.5mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，间隙不应过大，并留有(yǒu)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0~0.5mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">的钝边。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.8&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">双相不锈钢的焊接操作</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">双相不锈钢焊接时，应采用(yòng)正反面气體(tǐ)保护焊，正面背面都应采用(yòng)混合气體(tǐ)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Ar97.5%+N2.5% </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">进行保护，焊接前不得在焊件表面引弧和试验電(diàn)流，焊接时应按指定的焊接作业指导书进行施焊。在焊接前，管子两端用(yòng)布或胶皮封好，并留有(yǒu)进气孔和排气孔，焊缝间隙用(yòng)胶布贴好，并留有(yǒu)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">20~30mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">的長(cháng)度，使管子内部的空气能(néng)够排出，确保焊缝内部的气體(tǐ)保护效果。焊接时，焊枪不宜摆动，手法要稳，严格控制線(xiàn)能(néng)量，尽量采用(yòng)小(xiǎo)焊丝，严格控制電(diàn)流，弧長(cháng)尽量压低控制電(diàn)压，尽量用(yòng)大喷嘴，提高气體(tǐ)保护效果，降底</span><span style="font-family:'Times New Roman';"><span lang="EN-US">O</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">、</span><span style="font-family:'Times New Roman';"><span lang="EN-US">H</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">污染；引、收弧避开点焊点，防止产生二次</span><span style="font-family:'Times New Roman';"><span lang="EN-US">γ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">和</span><span style="font-family:'Times New Roman';"><span lang="EN-US">δ</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相，引弧点必须在焊道内进行，不能(néng)在母材表面引弧，防止</span><span style="font-family:'Times New Roman';"><span lang="EN-US">F</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">量超标；点焊点打磨后，封底焊焊接过程中通过观察焊道颜色来确定焊接气體(tǐ)保护效果，采用(yòng)混合气體(tǐ)施焊时焊道好為(wèi)金黄色，稍差一些為(wèi)黄铜色，尽量减少焊缝发蓝，杜绝焊道发灰和发黑，并严格控制层间温度，控制熔池在红热状态下停留时间。一般来讲，只要保证在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">5~15s</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">时间内熔池由红转至常规颜色，就能(néng)达到要求。打底焊的层间温度</span><span style="font-family:'Times New Roman';"><span lang="EN-US">≤100</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">℃，可(kě)用(yòng)遠(yuǎn)红外激光测温仪测量。当层间温度＜</span><span style="font-family:'Times New Roman';"><span lang="EN-US">100</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">℃时，才能(néng)进行下一层焊接，焊接電(diàn)流不能(néng)超过打底焊的電(diàn)流，焊**层必须认真清理(lǐ)前一层焊道，除消除杂质外，连氧化色也需磨去，焊缝内部余高应控制在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0.5 ~1mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">；焊缝收弧时应将弧坑填满，多(duō)层焊的层间接头应相互错开，如果焊接作业时不慎出现夹钨时，应停止焊接作业，用(yòng)磨光机消除钨点，钨极端部重新(xīn)磨尖，达到要求后方可(kě)重新(xīn)进行焊接作业，要求与开始焊接作业相同。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 2.9&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">焊后清理(lǐ)和焊接检验</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">双相不锈钢的焊后清理(lǐ)也很(hěn)重要，氧化色必须**，因為(wèi)氧化色下面就是贫铬层，若不去除将会导致耐蚀性能(néng)下降，去除氧化色可(kě)用(yòng)专用(yòng)不锈钢丝刷趁热擦刷；也可(kě)用(yòng)酸或酸洗膏清洗。去除焊接飞溅，打磨收起弧点，去除咬边和粗毛刺。可(kě)用(yòng)较细的砂轮片或抛光砂轮片研磨，杜绝粗糙打磨痕迹，否则易造成缝隙腐蚀；油污、着色剂、色筆(bǐ)印、灰尘均有(yǒu)可(kě)能(néng)成為(wèi)孔腐蚀和缝隙腐蚀的起始点，可(kě)用(yòng)硝酸</span><span style="font-family:'Times New Roman';"><span lang="EN-US">+</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">氢氟酸清洗，然后清水冲洗干净；焊工应对焊道表面进行清理(lǐ)，要求外观良好，宽度以每边盖过坡口边缘</span><span style="font-family:'Times New Roman';"><span lang="EN-US">2mm</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">為(wèi)宜，角焊缝的焊脚高度符合设计规定外形平稳过渡，焊缝不允许咬边、裂纹、未焊透、气孔、夹杂存在。射線(xiàn)探伤方法按《压力容器无损检测》</span><span style="font-family:'Times New Roman';"><span lang="EN-US">JB4730-g4</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">执行，所有(yǒu)焊道必须进行硬度测定，测定母材</span><span style="font-family:'Times New Roman';"><span lang="EN-US">-HAZ-</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">焊道</span><span style="font-family:'Times New Roman';"><span lang="EN-US">-HAZ-</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">母材。</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> 3&nbsp; &nbsp; </span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">结束语</span></span><span lang="EN-US"><br /> <span style="font-family:'Times New Roman';font-size:small;"> </span></span><span style="font-size:small;"><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">采用(yòng)上述焊接工艺和焊接操作要领，在仪征化纤</span><span style="font-family:'Times New Roman';"><span lang="EN-US">45</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">万吨</span><span style="font-family:'Times New Roman';"><span lang="EN-US">/</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">年</span><span style="font-family:'Times New Roman';"><span lang="EN-US">PTA</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">装置施工过程中进行双相不锈钢薄壁管现场施焊，取得了焊缝连续</span><span style="font-family:'Times New Roman';"><span lang="EN-US">5</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">个月</span><span style="font-family:'Times New Roman';"><span lang="EN-US">RT100%</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">合格，年度双相不锈钢焊接接头综合合格率达到</span><span style="font-family:'Times New Roman';"><span lang="EN-US">99%</span></span><span style="font-family:宋體(tǐ);mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以上的施焊业绩。</span></span> </p> <span style="font-family:宋體(tǐ);font-size:small;"> </span>