摘要
某厂生产的一支P110钢级套管在防腐现场被发现存在长约7m的纵裂裂纹。为分析裂纹产生的原因,通过宏观形貌观察、磁粉检测和化学成分分析、力学性能试验等,对该支套管进行了失效分析。试验结果表明,该套管材料的化学成分、力学性能指标等符合APISPEC5CT—2011标准要求。纵裂是由于裂纹形成于轧管初期或轧管之前,后续的热处理及静水压试验使其进一步扩展,应力释放的延时效应最终造成管体表面贯穿性纵向开裂。最后提出改进措施,降低了产品报废率,挽回了经济损失,提高和稳定了产品的成材率。
A P110 casing was found with a 7-meter length penetration longitudinal crack at the corrosion protection site.In order to analyze the causes of the cracks,the failure analysis was carried out by macro-morphology observation,magnetic particle detection,chemical composition analysis and mechanical property tests,etc.The results show that the chemical composition and mechanical properties of the failed casing were in accord with API SPEC 5CT-2011,and the defects were formed in the beginning or before the rolling process,and further extended in the subsequent heat treatment and hydrostatic testing.The time-delay effect of stress release ultimately results in penetrating longitudinal cracking.Finally,some reasonable improvement measures are given,which effectively reduced the scrap rate of products,recovered the economic losses,and improved the quality.
作者
崔绍华
谢培
崔智超
党民
CUI Shaohua;XIE Pei;CUI Zhichao;DANG Min(China Petroleum Technology & Development Corporation,Beijing 100028,China;China AnNeng Construction Group Co.,LTD,Beijing 100055,China)
出处
《石油管材与仪器》
2019年第3期33-37,共5页
Petroleum Tubular Goods & Instruments
关键词
P110套管
管体纵裂
裂纹扩展
改进措施
P110 steel grade casing
longitudinal cracks
crack propagation
improvement measures
