多次返修次数对SA-533GrBCL1钢焊接接头组织和性能的影响

Influence of Multiple Welding Repairs on the Properties of SA-533BCL1Steel Welded Joints

SA-533GrBCL1钢是核电站建设中使用较多的一种钢材,有一定的核级安全要求,为验证SA-533GrBCL1焊接稳定性。特开展焊条电弧焊多次返修对压力容器用钢板SA-533GrBCL1接头性能的影响研究,通过拉伸、弯曲、低温冲击和硬度试验等性能试验,分析多次返修(≤5次)的焊接接头不同位置的金相组织分布和变化规律。结果表明,SA-533GrBCL1焊接接头经过多次返修或返修焊后热处理,其接头力学性能未见异常变化,各项性能指标符合相关制造规范要求,但多次返修后热影响区较未返修接头存在软化,焊后热处理降解并平化了焊接接头各区域的硬度差异。焊缝金属和焊后热处理熔合区微观上表现为铁素体组织萌生针状、块状、片状形态转变,并伴生少量粒状贝氏体、珠光体组织形态,表现出冲击韧性值呈现分散性。

SA-533GrBCL1 steel is a kind of steel that is widely used in the construction of nuclear power plants.It has certain nuclear safety requirements to verify the welding stability of SA-533GrBCL1.Specially carry out research on the influence of electrode arc welding multiple repairs on the performance of steel plate SA-533GrBCL1 for pressure vessels.Through performance tests such as tensile,bending,low temperature impact and hardness tests,the different welding joints of multiple repairs(≤5 times)are analyzed.The metallographic structure distribution and variation law of the location.The results show that the mechanical properties of SA-533GrBCL1 welded joints have not changed abnormally after repeated repairs or post-weld heat treatment,and the performance indicators meet the requirements of relevant manufacturing specifications,but the heat-affected zone exists after repeated repairs compared with unrepaired joints.Softening,post-weld heat treatment degrades and smoothes out hardness differences in various areas of the welded joint.Microscopically,the weld metal and the fusion zone of the post-weld heat treatment show that the ferrite structure initiates acicular,block,and flake morphology transformation,and is accompanied by a small amount of granular bainite and pearlite structure,showing that the impact toughness value is dispersive.