特厚高强钢z向成分差异对焊接接头热输入的影响  

Effect of different Z-direction chemical composition and microstructural inhomogeneity on welding joint heat input

作　　者：张建强[1,2] 陈长风[1] 郑雁军[1] 张熹[2] 李涛[2] 张楠[2] 汪小培[2] 

机构地区：[1]中国石油大学(北京)理学院,北京102249 [2]首钢技术研究院,北京100043

出　　处：《焊接学报》2017年第1期112-116,共5页Transactions of The China Welding Institution

摘　　要：文中以两种150 mm特厚高强先进610CFD钢为试验对象,基于材料z向成分的差异,分析组织不均匀性对焊接接头热输入的影响,利用金相显微镜,SEM,EBSD和冲击试验对结果进行表征.结果表明,提高铸坯厚度、降低易偏析元素C,Mn等合金元素含量,可以有效的减小1/2处偏析程度并避免冶金缺陷,使宏观偏析转化为微观偏析;比较严重的宏观偏析造成1/4处、1/2处热影响区组织存在明显区别是造成其z向各位置焊接工艺适应性差异的主要原因;而微观偏析造成z向各位置焊接工艺适应性差异的机理是合金元素微观偏析造成热影响区MA数量、形貌、分布差异.The research objects were two types of advanced high strength steels 610 CFD with 150 mm thickness.Based on the different chemical composition of Z-direction,studied the effect of microstructure uneven on welding joint heat input. SEM,EBSD and impact tests were employed to characterize the results. The results show that improving casting billet thickness and reducing contents of segregation elemental,C and Mn is effective to reduce the segregation degree of 1/2 position and avoid metallurgical defects,thereby changing macro segregation into micro segregation; The obvious difference of 1/4 and 1/2position heat affected zone( HAZ) microstructure resulting from serious macro segregation is the main reason why welding process adaptability on all positions along Z-direction have so much differences,while the mechanism that micro segregation leads to bad welding process adaptability is that the segregation of alloying elements causes the difference of MA's amounts,morphology and distribution in HAZ.

关 键 词：高强钢 化学成分 焊接接头 热输入 热影响区 

分 类 号：TG401[金属学及工艺—焊接]