激光填丝焊碳钢车体不等厚对接接头疲劳性能

摘要

使用2.5 mm+4 mm的碳钢材料和ER50-G焊丝进行不等厚对接接头的激光填丝焊试验,研究不等厚对接接头的疲劳性能和断口的宏观及微观形貌,并分析其断口特征.结果表明,在指定寿命为1×107次循环时,接头的中值疲劳极限σ0.1为237.5 MPa.疲劳断裂发生在2.5 mm板一侧的焊趾处,断裂呈现典型的疲劳断裂特征,疲劳纹清晰,瞬断区断口形貌为大小不一的韧窝.该研究为激光填丝焊在碳钢车体制造上的应用提供了可靠的技术支撑.%Using 2.5 mm+4 mm carbon steel material and ER50-G welding wire to conduct laser filling wire welding test of unequal thickness butt joint.The fatigue properties and macroscopic and microscopic appearance of the unequal thickness butt joints are studied,and the fracture characteristics are analyzed.The results show that the fatigue value of the join is 237.7 MPa when the specified life cycle is 1×107.The fatigue fracture occurs at the welding toe on the side of the 2.5 mm plate.The fracture presents typical fatigue characteristics,and the fatigue lines are clear,and the fracture morphology of the transient area is a dimple of different sizes.This study provides a reliable technical support for laser fillet welding in the manufacture of carbon steel body.