摘要
管道法兰螺母开裂脱落,通过开裂口外观检查、宏观和微观分析、材料化学成分分析,保证载荷测试、硬度测试和显微组织测试等手段对法兰螺母开裂的原因进行了分析。结果表明:失效螺母的化学成分满足要求,但是碳含量远远偏离标准规定值。螺母表面宏观可见锻造成型不良缺陷;金相组织为铁素体+珠光体;保证载荷和硬度检验结果均不满足要求;螺母断口的微观形貌呈韧窝断裂,为螺母强度不足导致开裂。
The pipe flange nut cracked and fell off,and the reasons for the flange nut cracking were analyzed by means of cracking appearance inspection,macro and micro analysis,material chemical composition analysis,g uarantee load test,hardness test a nd microstructure test.T he results s how that the chemical composition of the failed nut meets the requirements,but the carbon content is far from the standard value.Macroscopically visible defects caused by forging on the nut surface;the metallographic structure is ferrite+pearlite;ensure that the load and hardness test results do not meet the requirements;the microscopic appearance of the nut fracture is dimple fracture,which is caused by insufficient nut strength.
作者
胡斌
徐科
徐柱
HU Bin;XU Ke;XU Zhu(CNNP Nuclear Power Operations Management Co.,Ltd.,Jiaxing,Zhejiang Province,314300 China)
出处
《科技创新导报》
2021年第2期17-20,56,共5页
Science and Technology Innovation Herald
关键词
螺母
开裂
测试
质量
Nut
Cracking
Test
Quality
