BTi-62421s合金板钨极氩弧焊接头组织性能研究  

Microstructure and Mechanical Properties of TIG Welded Joint of BTi- 62421S

作　　者：彭小敏[1] 孙玮[2] 夏长清[2] 

机构地区：[1]湖南工程学院机械工程学院,湖南湘潭411101 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《矿冶工程》2013年第5期119-123,共5页Mining and Metallurgical Engineering

基　　金：国家自然科学青年基金项目(51101054);湖南工程学院科研启动项目

摘　　要：研究了焊前热处理、焊接工艺及焊后热处理对BTi-62421s板材钨极氩弧焊接头组织性能的影响。结果表明:BTi-62421s合金板材钨极氩弧焊较佳焊接工艺为:焊接电流110 A,焊接速度5 mm/s,主喷嘴氩气流量20 L/min,拖罩氩气流量12 L/min,单面焊接,此工艺下双重退火态BTi-62421s合金焊接接头抗拉强度σb为1 033 MPa,为母材的96.5%,延伸率δ为5.5%,为母材的38.5%;焊缝组织为针状马氏体,热影响区组织为初生α组织、β转变组织和针状马氏体组织;合金焊前双重退火和去应力退火对焊缝组织组成影响有限,但双重退火有助于焊接接头塑性的提高;焊后热处理促进合金接头α'→α+β相转变,有利于焊接接头塑性的提高,较佳焊后热处理工艺为700℃/2 h,空冷,此工艺下双重退火态BTi-62421s合金焊接接头延伸率δ为7.1%,为母材延伸率的49.5%。The effect of pre-weld heat treatment, welding procedure and post-weld heat treatment on the microstructure and mechanical properties of TIG welded joint on BTi-62421S plates was studied. Results show that preferable parameters for TIG welding of BTi-62421S plates are as follows： welding current of 110 A, welding speed of 5 mm/s, main nozzle argon gas flow of 20 L/min, drag cover argon gas flow of 12 L/min and with a single-side welding technique. With this approach, the tensile strength O＇b and elongation percentage 8 for the welded joint of double annealed BTi-62421S reached 1 033 MPa and 5.5%, respectively, which was correspondingly 96.5% and 38.5% of the base metal. The weld seam metal was indentified as aeieular martensite and the heat-affected zone was consisted of primary α phase, transformed 13 phase and acieular martensite. Although pre-weld heat treatment of BTi-62421S had little effect on microstructure of welded joint, the ductility of the joint could be improved by double annealing of BTi-62421S. The post-weld heat treatment promoted α＇→＋α＋β transformation, which was beneficial to enhance plasticity of the joint. And the preferable conditions for post-weld heat treatment of BTi-62421S were 700 ℃/2 h and AC, with which 8 for the welded joint of double annealed BTi-62421S reached 7.1%, namely, 49.5% of the base metal.

关 键 词：BTi-62421s合金 钨极氩弧焊 焊接接头 显微组织 力学性能 

分 类 号：TG457.19[金属学及工艺—焊接]