摘要
近年来,国内外已将激光焊技术应用至轨道交通制造行业。为了研究不同焊接工艺对耐候钢激光焊T形接头疲劳强度的影响,文中以Q310NQL2耐候钢薄板为研究对象,开展了激光焊T形接头双面焊未焊透、双面焊焊透和单面焊试验,采用升降法计算3种工艺下的疲劳强度,并通过宏观金相、有限元方法和断口扫描对其进行了分析。结果表明:单面焊T形接头疲劳强度高于双面焊接头的。宏观金相和有限元分析发现,单面焊接头应力集中程度较小,故疲劳强度较高。疲劳断口分析发现,与双面焊工艺的T形接头相比,单面焊工艺在裂纹扩展时需要克服更大的阻力,疲劳强度更高。因此,对于耐候钢薄板激光焊T形接头采用单面焊工艺可以获得更高的疲劳强度。
In recent years, laser welding technology has been applied to the rail transit manufacturing industry at home and abroad. In order to study the influence of different welding processes on the fatigue strength of weathering steel laser welded T-joints, this article took Q310 NQL2 weathering steel sheet as the research object, and carried out laser welding T-joint welding by both sides incomplete penetration, welding by both sides penetration and welding by one side. In welding experiments, the lifting method was used to calculate the fatigue strength under the three processes, and it was analyzed by macroscopic metallography, finite element method and fracture scanning. The results showed that the fatigue strength of one side welded T-joints was higher than that of both sides welded joints. Macroscopic metallographic and finite element analysis found that the stress concentration of single-sided welded joints was lower, so the fatigue strength was higher. Fatigue fracture analysis found that, compared with the T-joint of the both sides welding process,the welding process needed to overcome greater resistance during crack propagation, and the fatigue strength was higher. Therefore, the welding by one side process could obtain higher fatigue strength for the laser welding T-joint of weathering steel sheet.
作者
张运通
孙杨
魏巍
孙屹博
杨鑫华
ZHANG Yun-tong;SUN Yang;WEI Wei;SUNYi-bo;YANG Xin-hua(School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,Liaoning pro.,China;Key Laboratory of Welding and Reliability of Rail Transit Equipment of Liaoning Province,Dalian 116028,Liaoning pro.,China)
出处
《焊接技术》
2021年第12期17-21,I0011,I0012,共7页
Welding Technology
基金
辽宁省高等学校国(境)外培养项目(2018LNGXGJWPY-YB012)。
关键词
激光焊T形接头
疲劳强度
应力集中
断口扫描
laser welded T-joint
fatigue strength
stress concentration
fracture scan
