22MnB5热成形钢板钨极氩弧焊接性能  

Weldability of 22MnB5 after hot stamping by TIG welding processes

作　　者：李欣[1] 王刚[1] 陆冠含 谷诤巍[1] 徐虹[1] 

机构地区：[1]吉林大学材料科学与工程学院,长春130022

出　　处：《吉林大学学报（工学版）》2014年第3期708-711,共4页Journal of Jilin University:Engineering and Technology Edition

基　　金：吉林省科技发展计划项目(20110301);国家自然科学基金项目(51101072)

摘　　要：对采用钨极氩弧焊接工艺(TIG)的厚度为4mm的22MnB5热成形钢板的焊接性能进行了研究,分析了不同焊接参数下接头的微观组织和力学性能。结果表明:采用直流TIG焊工艺,在其他焊接参数一定的条件下,当焊接电流为60A和100A时,所焊试件均出现焊接缺陷;焊接电流为80A时,焊接试件虽无宏观缺陷,但焊缝金属中出现魏氏组织。采用直流脉冲TIG焊工艺,在平均电流为60A时能够使焊接试件良好成形,试件焊缝及热影响区粗晶区、细晶区均为铁素体和珠光体的混合组织,热影响区内高温回火区由板条马氏体、下贝氏体及珠光体构成,低温回火区内碳化物呈粒状析出。随着距焊缝中心距离的增加,接头的显微硬度呈上升趋势,抗拉强度为631MPa,仅为母材的42.1%。Tungsten Inert Gas （TIG） welding technology was employed to study the weldability of THQ50-C filler metal of 4 mm sheet thickness 22MnB5 after hot stamping. The microstructures and mechanical properties of the welding joints under different welding parameters were analyzed. Results show that, under the condition of DC-TIG welding, welding defects were found when the welding current is 60 A and 100 A; at 80 A welding current no macroscopical were found on the test pieces, but widmanstatten structure appeared in weld metal. While the DC pulse TIG welding was applied, high quality joint was available when the average welding current was only 60 A. The weld metal, coarse and fine grain zones of Heat Affected Zone （HAZ） were all composed of ferrite and pearlite; lath martensite, lower bainite and pearlite distributed in high temperature tempering zone of HAZ; granular carbide was separated out from the lath martensite in low temperature tempering zone of HAZ. Microhardness of the test pieces increased with the distance from the weld center, but the tensile strength was 631 MPa, about 42.1% of that of base material.

关 键 词：金属材料 钨极氩弧焊接 热成形 微观组织 力学性能 

分 类 号：TG442[金属学及工艺—焊接]