摘要
夹紧带在进行振动试验时焊点处发生断裂,对断裂的夹紧带进行了断口的宏观、微观形貌观察、化学成分分析、金相组织分析、硬度测试和焊点质量检验。结果表明,焊接工艺控制不当造成热影响区组织过热以及焊点压痕深度过大是导致夹紧带脆性断裂的主要原因;另外,原材料强度偏高,导致焊接性能和断裂韧性下降,增加了脆断倾向。通过采用较低强度的冷作硬化状态钢带进行焊接加工,改善焊接工艺,优化焊接接头参数,产品经过振动试验未发生断裂失效。
A clamp strip fractured at the welding point during vibration testing. Macro and micro appearances and metallurgical microstructure of the fracture surface were observed. Chemical composition analysis, hardness testing and welding point quality inspection were carried out. The results showed that the fracture mode was brittle fracture and the fracture was mainly caused by overheating of the heat-affected zone and the large depth of the pressure mark at the welding point. Both the factors resulted from improper welding techniques. In addition, the high material intensity resulted in the decline of the welding performance and fracture toughness, and the tendency of brittle fracture was promoted accordingly. It was also found that the fracture could be avoided by meaning of employing lower intensity material and improving the welding techniques.
出处
《失效分析与预防》
2008年第3期55-58,共4页
Failure Analysis and Prevention
关键词
夹紧带
电阻焊
脆性断裂
clamp strip
electric resistance welding
brittle fracture
