NiCrFe合金补焊15Cr2Mo1耐热钢焊缝组织与力学性能  

Microstructure and mechanical properties of weld of 15Cr2Mo1heat resistant steel repaired by NiCrFe filler alloy

作　　者：常子金 晏嘉陵 齐彦昌[1] 崔冰[1,3] 蔡啸涛 CHANG Zijin;YAN Jialing;QI Yanchang;CUI Bing;CAI Xiaotao(Welding Institute,Central Iron and Steel Research Institute,Beijing 100081,China;East China Electric Power Test and Research Institute,China Datang Group Science and Technology Research Institute Co.,Ltd.,Hefei 230088,China;School of Materials Science and Engineering,Anhui University of Technology,Maanshan 243032,Anhui,China)

机构地区：[1]钢铁研究总院焊接研究所,北京100081 [2]中国大唐集团科学技术研究院有限公司华东电力实验研究院,合肥230088 [3]安徽工业大学材料科学与工程学院,安徽马鞍山243032

出　　处：《材料工程》2023年第3期156-165,共10页Journal of Materials Engineering

摘　　要：针对15Cr2Mo1耐热钢焊缝服役过程中易出现表面裂纹的问题,采用与该钢种使用场景相似的NiCrFe合金对预制不同坡口深度来模拟裂纹深度的焊缝进行补焊。通过补焊焊缝组织及性能表征,验证补焊修复工艺的适用性。结果表明:不同深度裂纹补焊后均成型良好且无明显缺陷,焊缝金属均由奥氏体胞状树枝晶及第二相析出物组成,熔合区附近存在少量共晶铁素体,但Ⅱ型边界与熔化边界间的白亮条带中不存在铁素体。补焊填充量的增加主要使接头的屈服强度降低,尤其坡口深度由6.5 mm增加至13 mm时,室温及高温屈服强度均大幅度降低15%左右,此后降低趋势减缓。填充量增加使熔合线及熔合线外2 mm区域冲击韧性提高,而全焊缝硬度随填充量增大呈现先减小后增大的特点,这与补焊缝所受的拘束作用、合金元素偏析形成析出相增多有关。Aiming at the problem that surface cracks occur in the service of 15Cr2Mo1 heat resistant steel welds,NiCrFe alloy which was similar to the usage scenarios of this steel was employed to repair welds with different groove depths simulating crack depths.The feasibility of repair process was verified by the microstructure and performance characterization of the welds.The results show that repair welding at different groove depths is well formed and has no obvious defects,the weld metal is composed of austenitic cell dendrites and second phase precipitates,and there are a small amount of eutectic ferrite near fusion area,however,there is no ferrite in the bright white strip between the typeⅡboundary and the melting boundary.The increase of repair welding filler mainly reduces the yield strength of the joint,especially when the groove depth increases from 6.5 mm to 13 mm,the yield strength at room and high temperature is both greatly reduced by about 15%,then the decline trend slows down.With the increase of filler amount,the impact toughness of the fusion line and the 2 mm area outside the fusion line is improved,while the hardness of the whole weld decreases first and then increases with the increase of filler amount,which is related to the restraint of the repairing weld and the increase of precipitates formed by alloy element segregation.

关 键 词：15Cr2Mo1耐热钢 填充量 补焊修复 表面裂纹 力学性能 

分 类 号：TG444[金属学及工艺—焊接]