采用扫描电镜、能谱分析等手段分析了某机电产品用不锈钢波纹管开裂的原因。结果表明: 在焊接过程中波纹管的焊接接头区域发生敏化, 随后酸洗造成该区域形成沿晶界腐蚀裂纹, 波纹管在经过振动试验时承受径向交变载荷, 在交变应力下裂纹由最初的晶界腐蚀裂纹根部开始扩展直至穿透管壁;断口表面能够发现明显的贝纹线, 证明波纹管开裂是一种疲劳失效。

The cracking cause of corrugated pipe of stainless steel used in an electromechanical product was analyzed by means of SEM, energy spectrum and so on. The results showed that the welded joint region was sensitized during welding, subsequently, corrosion crack along the grain boundary formed by pickling, the corrugated pipe bore radial direction alternating load during the vibration test, the crack began to extend from the bottom of intergranular corrosion cracks, lastly, the crack penetrated the pipe wall. The fracture surface characterized with obvious cowrie pattern lines, that proved the corrugated pipe occurred fatigue failure.