含铜时效钢焊接粗晶区组织转变特征研究  

Research on microstructure transformation characteristics in CGHAZ of copper-bearing aging steel

作　　者：徐魁龙[1] 柴锋[1] 苏航[1] 

机构地区：[1]钢铁研究总院工程用钢所,北京市100081

出　　处：《焊接》2013年第4期51-54,72,共4页Welding & Joining

摘　　要：采用Gleeble-3800焊接热模拟机模拟研究了含铜时效钢焊接粗晶区的组织转变规律,测定了SHCCT曲线,分析研究了冷却速度对其组织形貌、晶粒度和硬度的影响规律。结果表明,冷却速度较快时(t_(8/5)<15 s),含铜钢的焊接粗晶区组织以板条贝氏体为主,晶粒尺寸相对较小,硬度较高;冷却速度较慢时(t_(8/5)>40 s),焊接粗晶区的组织主要由粒状贝氏体构成,原始奥氏体晶粒尺寸粗大,同时在铁素体基体上分布着较多大尺寸的M-A岛,M-A岛的形成导致焊接粗晶区的低温韧性严重恶化。The microstructure transformation of CGHAZ(coarse grain heat-affected zone) in copper-bearing aging steel was studied by using thermal simulator of Gleeble-3800.And the SHCCT curve of experimental steel was drawn to analyze the effects of cooling rate on the microstructure,hardness and grain size in CGHAZ.The results indicates that when the cooling rate is fast(t_(8/5)<15 s),the microstructure of CGHAZ in copper-bearing aging steel is almost lath bainite.In addition,and the grain size is relatively finer,and the hardness is relatively higher.However,when the cooling rate is slow(t_(8/5)>40 s),the microstructure is mainly granular bainite in CGHAZ.And the grain size of original austenite is coarse.Meanwhile many large size M-A islands structure is distributed in the ferritic matrix,which causes a serious deterioration to the low temperature toughness of CGHAZ.

关 键 词：含铜时效钢 粗晶区 M—A岛 粒状贝氏体 

分 类 号：TG407[金属学及工艺—焊接]