摘要
抽油杆断脱给油田造成了巨大的经济损失。以外螺纹接头断裂的抽油杆为研究对象,经过强度校核,其结构满足正常工作要求。对断口形貌进行宏观和微观观察,并对断杆进行硬度和金相组织分析,发现断口呈现疲劳及准解理混合断裂形貌,原因是热处理过程中过热影响了晶粒分布,降低了杆柱的韧性与塑性,增加了其脆性,导致抽油杆在外螺纹根部因应力集中而出现疲劳裂纹,并快速扩展,引起疲劳准脆性断裂失效。
Via different types of sucker rod string failure data statistics, it was found that heat treatment was one of the early brittle fracture fatigue failure. In order to study the failure mechanism, an oil production plant vitiated sucker rod string was given as an example, in which external thread join was rupture. After checking the strength, its structure met the normal require- ments. Through observing the fracture topographic image in macroscopy and microscopy two angles, as well as using the hardness analysis and the metallographic examination with the broken rod, the basic reason was found, which lead to the sucker rod string rift overheated in the heat treatment. Thus it affected the distribution of the crystalline particle, reduced toughness and plasticity of the rod, increased its brittleness, made the fatigue crack occurrence on the roots of the outside thread because of stress concentration, then created the brittleness fatigued failure owing to the fatigue crack rapidly expanded.
出处
《石油矿场机械》
2009年第11期54-56,共3页
Oil Field Equipment
基金
西南石油大学校自然科学基金"井下工具设计新方法研究"(2007XJZ093)
关键词
抽油杆柱
疲劳失效
热处理
金相分析
sucker rod string
fatigued failure
heat treatment
metallographic examination
