焊接热循环对热轧Giga钢板焊接粗晶区组织和韧性的影响  

Effect of Welding Thermal Cycle on Microstructure and Toughness of Coarse-grained Heat Affect Zone in Hot-rolled Giga Steel Plate

作　　者：王海波[1] 方俊飞[2] 彭欢[1] WANG Haibo;FANG Junfei;PENG Huan(Maanshan lron and Steel Co.,Ltd.,Ma'anshan 243002,Anhui China;School of Materials Science and Engineering,Anhui University of Technology,Ma'anshan 243000,Anhui China)

机构地区：[1]马鞍山钢铁股份有限公司,安徽马鞍山243002 [2]安徽工业大学材料科学与工程学院,安徽马鞍山243000

出　　处：《热处理》2021年第2期26-30,共5页Heat Treatment

基　　金：安徽省科技重大专项资助项目(18030901075)。

摘　　要：采用Gleeble-3500热模拟试验机对厚度为6 mm的热轧Giga钢板进行了单道次焊接热模拟试验,研究了单道次焊接热循环时间(t8/5)对焊接粗晶区显微组织和韧性的影响。结果表明:单道次焊接热循环时间t8/5从15 s增加至120 s时,粗晶区组织由板条马氏体转变为贝氏体,晶粒粗化,硬度降低,韧性先增加后降低;当t8/5为30 s时,粗晶区冲击韧度最高,为82 J;t8/5较小时,冲击试样为韧性断裂;而当t8/5超过60 s时,冲击试样为脆性断裂。The one-pass welding thermal simulation test for the 6-mm-thick hot-rolled Giga steel plate was carried out by Gleeble-3500 thermal simulator.The effect of thermal cycle time of one-pass welding(t8/5) on microstructure and toughness of coarse-grained heat-affected zone(CGHAZ) were investigated.The results showed that(a) as the t8/5 increased from 15 to 120 s,the microstructure of the CGHAZ changed from lath martensite to bainite,the grain coarsened,the hardness decreased,and the toughness increased at first and then decreased;(b)the CGHAZ had the highest impact toughness of 82 J when t8/5 was 30 s;and(c) the impact specimen was ductile fracturing when the t8/5 was less,and was brittle fracturing when the t8/5 exceeded 60 s.

关 键 词：热轧钢板 焊接粗晶区 显微组织 韧性 热模拟试验 

分 类 号：TG406[金属学及工艺—焊接]