高压蒸汽管道封头开裂失效分析

摘要

In order to find out the cracking causes of a head of high pressure steam pipe,the head was an-alyzed for the cracking morphology analysis,the fracture analysis and microstructure analysis.The results showed that the cracking failure character of the head was thermal fatigue.The main factor of the head cracking cause was the leakage of rain for a long time on high temperature head outer wall quench and produce thermal stress.Head forging process produce microstructure defects that promote the crack initia-tion and propagation.Combining with the actual situation,remedial measures were taken to avoid the simi-lar failure accidents.%为了查明高温蒸汽管道封头开裂失效原因，针对封头进行了开裂形貌、裂纹断口和金相组织等检测分析。结果表明：封头开裂的失效性质是热疲劳，造成封头开裂的主要原因是雨水长期泄漏对高温封头外壁急冷产生热应力，封头锻造工艺造成的组织缺陷也促进了裂纹的萌生和扩展。结合现场实际情况，提出了一些建议措施，避免了类似失效事故的发生。