焊接残余应力对P92钢Ⅳ型蠕变开裂的影响  

Effect of welding residual stress on type Ⅳ creep failure of P92 steel

作　　者：姜运建[1,2,3] 荆洪阳[1,2] 徐连勇[1,2] 王庆[3] 代真[3] 

机构地区：[1]天津大学材料科学与工程学院,天津300072 [2]天津市现代连接技术重点实验室,天津300072 [3]河北省电力研究院,石家庄050021

出　　处：《焊接学报》2011年第1期16-20,113-114,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(50805103);天津市自然科学基金资助项目(08JCZDJC18100)

摘　　要：P92钢焊接接头在高温长时服役条件下易于在细晶热影响区(FGHAZ)或临界热影响区(ICHAZ)产生Ⅳ型裂纹.但对于Ⅳ型开裂的机理,至今尚未达成一致认识.为了科学地认识Ⅳ型开裂,文中采用大型有限元软件ABAQUS对P92钢焊接接头的温度场、应力场以及蠕变进行了有限元模拟,并且通过X射线测量试验对残余应力模拟值进行了验证.结果表明,通过温度场模拟,得到了FGHAZ与ICHAZ的准确位置;焊接残余应力最大值集中在FGHAZ和ICHAZ,并且轴向蠕变应变分布规律与焊接残余应力相一致.因此焊接残余应力的集中,是导致焊接接头蠕变应变聚集和Ⅳ型开裂的关键因素之一.Type Ⅳ cracking is considered to be the likely failure mode of P92 steel welds when operated at high temperature for long duration.Type Ⅳ failure often takes place at the intercritical heat affected zone（ICHAZ） or fine grained heat affected zone（FGHAZ）.However,the mechanism of type Ⅳ cracking has not yet been understood unequivocally.In order to investigate type Ⅳ failure scientifically,temperature field,welding residual stress and creep strain for welded joint of P92 steel are simulated by ABAQUS code.Experimental result obtained from X-ray diffraction technique is conducted to verify the simulation.The research results show that the locations of ICHAZ and FGHAZ are demonstrated according to the simulation of temperature field.Maximal residual stress concentrates in the ICHAZ and FGHAZ.And axial creep strain is in good agreement with residual stress.So concentration of residual stress that results in accumulation of creep strain and type Ⅳ cracking is regarded as remarkable factor.

关 键 词：P92钢 Ⅳ型裂纹 温度场 焊接残余应力 有限元模拟 

分 类 号：TG404[金属学及工艺—焊接]