440CL钢轮辋焊缝开裂的原因  

Cause for Cracking of Weld of 440CL Steel Rim

作　　者：赵琼 刘西峰 袁月 赵磊磊 王正康 ZHAO Qiong;LIU Xifeng;YUAN Yue;ZHAO Leilei;WANG Zhengkang(Shanxi Jianlong Industrial Co.,Ltd.,Yuncheng 043801,Shanxi China;Xinxing Transportation Construction Co.,Ltd.,Yantai 264001,Shandong China)

机构地区：[1]山西建龙实业有限公司,山西运城043801 [2]新兴交通建设有限公司,山东烟台264001

出　　处：《热处理》2024年第1期42-44,48,共4页Heat Treatment

摘　　要：440CL钢汽车轮辋焊缝在扩径过程中开裂。对焊缝开裂的两件轮辋(被编为1和2号)进行了宏观检验、化学成分分析、断口分析、硬度测定、金相检验和能谱分析,以明确焊缝开裂的原因。结果表明:1号轮辋与2号轮辋焊缝开裂的原因不同,1号轮辋是铜脉冲电极受热熔化并进入焊缝,焊缝有块状铁素体和魏氏组织,力学性能降低,扩径或滚压变形时焊缝开裂;2号轮辋是闪光焊时热输入量较大,导致焊缝形成网状铁素体和魏氏组织等异常组织,晶粒粗化,且存在密集氢气孔,从而焊缝力学性能降低,扩径时开裂。Weld of 440CL steel rims which were numbered 1 and 2 cracked during expanding.Macro-check,chemical composition analysis,fracture testing,hardness testing,metallographic examination and energy spectrum analysis were performed on the two pieces of rim whose weld cracked,to identify the cause for weld cracking.The results indicated that the rim No1 differed from the rim No2 in the cause of weld cracking,the weld cracked during expanding because copper pulse electrode was heated to melting and entered into the weld,and both blocky ferrite and Widmannstaetten structure existed thereby mechanical properties decreased in the weld for the rim No.1,and because lager thermal input coming from flash welding resulted in formation of abnormal structure such as ferrite network and Widmannstaetten structure,the grain coarsened and the close hydrogen gas holes existed thereby mechanical properties decreased in the weld for the rim No.2.

关 键 词：轮辋 焊缝 开裂 闪光焊 晶粒粗化 扩径 

分 类 号：TG115[金属学及工艺—物理冶金]