焊接式法兰截止阀阀体裂纹失效分析  

Failure Analysis of Welded Flange Cut⁃off Valve Body Crack

作　　者：李冬 郭雷 郭磊 许彦 刘迎来[1,2] 吴金辉 LI Dong;GUO Lei;GUO Lei;XU Yan;LIU Yinglai;WU Jinhui(CNPC Tubular Goods Research Institute,Xi´an 710077,China;Beijing Longshine Oil Tubular Technology Co.,Ltd.,Beijing 100101,China)

机构地区：[1]中国石油集团工程材料研究院有限公司,西安710077 [2]北京隆盛泰科石油管科技有限公司,北京100101

出　　处：《焊管》2025年第3期68-72,共5页Welded Pipe and Tube

摘　　要：针对某站场用焊接式法兰截止阀存在的疑似裂纹缺陷,通过化学分析、硬度测试、金相组织观察、扫描电镜及能谱检测对法兰阀体开裂原因进行了分析。结果表明,阀体的化学成分和硬度均满足标准要求;组装时的约束应力导致折叠缺陷扩张是造成阀体发生早期裂纹的主要原因。建议阀体制造时,确保有效清除坯料表面的氧化皮及表面缺陷,并对阀体进行100%内外表面无损检测。Aiming at the suspected crack defects in the welded flange cut-off valve used in a station,the cracking reason of the flange valve body was analyzed by chemical analysis,hardness test,metallographic structure observation,scanning electron microscope and energy spectrum detection.The results show that the chemical composition and hardness of the valve body meet the standard requirements.The expansion of the folding defect caused by the constraint stress during assembly is the main reason for the early crack of the valve body.It is recommended to ensure that the oxide scale and surface defects of the billet are effectively removed when the valve body is manufactured,and 100%non-destructive testing of the inner and outer surfaces of the valve body is carried out.

关 键 词：焊接式法兰截止阀 阀体 裂纹折叠缺陷 

分 类 号：TG316.1[金属学及工艺—金属压力加工]