热处理时间对CLAM钢TIG焊接头组织和性能的影响  

Effect of heat treatment time on microstructure and mechanical properties of TIG welded joint of China low activation martensitic steel

作　　者：王旭[1] 何晗[1] 李磊[1] 秦向多 雷玉成[1,2] 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013 [2]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150000

出　　处：《焊接技术》2016年第4期18-21,5,共4页Welding Technology

基　　金：先进焊接与连接国家重点实验室项目(AWJ-Z13-01)

摘　　要：采用钨极氩弧焊(TIG焊)方法对厚5 mm中国低活化马氏体钢(CLAM钢)进行平板对接焊,焊后分别进行750℃×30 min,750℃×60 min,750℃×90 min回火热处理,并对焊接接头的力学性能和显微结构进行分析测试。结果表明,CLAM钢采用TIG焊可以获得良好力学性能的板条状马氏体焊缝组织,焊后热处理后观察到大量的碳化物析出;焊后热处理时间与马氏体板条尺寸正相关,随着时间增长碳化物析出并向晶界处聚集;焊接接头的硬度和抗拉强度随着热处理保温时间的延长而降低,而冲击吸收功会先提高后降低,在750℃×60 min热处理后的冲击吸收功最大。热处理保温时间在60 min时焊缝的综合力学性能最好。TIG welding was used for butt welding of China low activation martensitic steel plate of 5 mm thickness.Post welding heat treatment(PWHT) was performed at different heat treatment parameters that were 750 ℃/30 min,750 ℃ /60 min and 750 ℃ /90 min. The mechanical properties and microstructure analysis were carried out on TIG welded joints after post welding heat-treatment. The results showed that the mechanical properties of CLAM steel TIG welding could get a good weld line microstructure, which was mainly lath martensite, there were a large amount of carbide dissolved out after post weld heat-treatment. With the increase of heat treatment time, the size of the martensitic lath was growing and the carbides would dissolve out and diffuse to the grain boundary. The hardness and tensile strength would bring down with the increase of heat treatment time, but the impact absorbing energy would increase first then reduce after. The impact absorbing energy achieved maximum under the PWHT of 750 ℃ /60 min.The comprehensive mechanics performance would be the best when the heat treatment time was 60 min.

关 键 词：CLAM钢 焊后热处理 碳化物 冲击吸收功 

分 类 号：TG441.8[金属学及工艺—焊接]