焊后热处理对12Cr1MoVG/12Cr2MoWVTiB钢焊接接头组织性能的影响  

Effect of postweld heat-treatment on microstructure and properties of 12Cr1MoVG/12Cr2MoWVTiB steel welded joints

作　　者：王香云[1] 雷文娟[1] 

机构地区：[1]太原锅炉集团有限公司,山西太原030021

出　　处：《金属热处理》2011年第6期92-96,共5页Heat Treatment of Metals

摘　　要：对12Cr1MoVG/12Cr2MoWVTiB异种钢焊接接头焊态及不同热处理温度下（720-770℃）的接头组织、硬度及拉伸、冷弯性能进行了测定。结果表明,随着热处理温度的提高,焊缝组织由回火马氏体＋少量颗粒状贝氏体逐步转变为粒状贝氏体＋索氏体组织,两侧焊缝硬度差异缩小,组织均匀化程度提高,晶粒有长大倾向。接头强度呈下降趋势,740℃强度下降趋缓,这是由于焊接残余应力得到大幅度释放,同时沉淀相的弥散强化作用增强所致。试验表明,730-770℃保持1 h焊后热处理制度均可满足使用性能要求,以740-760℃保持1 h热处理制度为佳。The microstructure,hardness,mechanical properties including bend and tensile strength of welded joints for 12Cr1MoVG/12Cr2MoWVTiB dissimilar steel as welded and under different temperature of postweld heat treatment were investigated.The results indicate that as temperature of postweld heat treatment increases,microstructure of welded joint turns from temper martensite and a small amount granular bainite to granular bainite and sorbite mixture of gradually,the hardness difference of two-sided weld become diminution.The structural homogenity is improved and the grain size grows up.And tensile-strength and hardness of joint show a trend of decreasing.Because of the substantial relaxation of welding residual stress and the dispersion strengthening of precipitated phase,the decreasing trend becomes less obvious at 740 ℃.It is found that all 730-770 ℃ for 1 h heat treating regimes can comform to operating performance characteristics.In order to prevent the adverse influence on plasticity and toughness,740-760 ℃ for 1 h heat treating regimes is preferred.

关 键 词：12Cr1MoVG/12Cr2MoWVTiB钢 焊接接头 焊后消除应力热处理 组织及性能 

分 类 号：TG441.8[金属学及工艺—焊接]