高压慢拉伸试验机加载系统故障诊断及排除

摘要

石油石化行业中易于发生应力腐蚀的金属结构多处于高压环境下工作,而慢应变速率拉伸(SSRT)试验是评价应力腐蚀敏感性的有效手段.有必要针对石油高校的学生开设高压环境下的SSRT教学实验.中国石油大学(华东)引进了国外某公司生产的高压SSRT试验机,在实验过程中遇到了加载系统偏转的问题.通过对试验机的加载原理进行分析,采用排查法确定设备的失效环节,进而制定解决措施.结果发现,设备失效缘于丝杠与销钉定位接头之间采用螺纹装配配合焊接的连接方式,易于产生应力集中,且焊接质量差,连接处发生脱焊.提出了3种维修方案,并针对现有配合模式进行了焊接修复,没有出现焊接裂纹和焊接变形,实现了慢应变速率拉伸试验机的正常运转,保证了实验教学的正常进行.%Most of metal structures in petroleum and petrochemical industry that are sensitive to stress corrosion have been usually working in high pressure environment,and slow strain rate tension (SSRT) tests are widely used to evaluate the sensitivity of stress corrosion.It is necessary to give students in petroleum universities an SSRT experimental teaching under high pressure.An SSRT testing machine equipped with autoclave was purchased from a foreign company,however,the measurement of deformation failed abruptly during tension testing.This paper describes the fault diagnosis process,and gives two possible resolutions.The results showed that the equipment failure arose from the joining failure between guide screw and locator.The presence of threads could lead to stress concentration and reduce the weld quality,and the weld fractured completely.Welding methods,filler metal and welding procedure were carefully chosen in order to avoid cracking and welding distortion.The testing machine finally returns to normal,and ensures the quality of experimental teaching.