热处理工艺对HFW焊缝显微组织和力学性能的影响

通过Gleeble热模拟设备来完成焊后正火和淬火+回火热处理,此工艺可用于提高细晶粒高频焊接钢管焊缝的韧性,并和广泛应用于管道敷设的X65钢级进行了比较.通过光学显微镜和透射电镜,对其微观结构演化进行了研究,采用维氏硬度和夏比V形缺口冲击韧性试验,评估其力学性能.正火热处理的力学性能满足API规范,而淬火+回火热处理工艺取决于X65钢和细晶粒钢的回火温度,因此,正火热处理工艺对于两种钢管更有效.

Effects of Post-weld Heat Treatment Cycles on Microstructure and Mechanical Properties of Electric Resistance Welded Pipe Welds

Two post-weld heat treatment cycles of one-step normalizing and two-step quenching and tempering have been performed by Gleeble,a thermo-mechanical simulator,to improve the toughness of fine-grained electric resistance welded pipe welds.Comparison was made to X65 grade steel,which is widely used for pipeline parts.Microstructural evolution was investigated by optical microscopy and transmission electron microscopy.Vickers hardness and Charpy V-notch impact toughness tests were used to evaluate the mechanical properties.While the mechanical properties of one-step normalizing heat treatment satisfied the API specification,the two-step quenching and tempering heat treatments were conditional upon tempering temperature for X65 grade and fine-grained steels.As a result,a one-step normalizing heat treatment was more effective for both steel pipes.