摘要
通过对某电厂中压外缸两根螺栓进行断面扫描、常温下性能试验、化学成分分析、冲击试验、常温金相组织分析、断面能谱分析,并结合螺栓现场使用的实际情况,得出螺栓补焊区的存在,加剧了螺栓组织的均匀性,同时也改变了螺栓性能的各向同性,为裂纹的产生创造了条件;组织偏析、制造残余缺陷等因素也改变了螺栓性能的各向同性,减弱了螺栓的局部的性能,是螺栓失效的主要原因;还有汽缸由于设计等原因在使用过程中发生变形,出现了外张口,改变了螺栓的受压状况,是螺栓失效的外在原因。
Profile scanning, performance test under normal temperature, analysis on chemical component, impact test, metallurgical structure analysis under normal temperature and energy spectrum analysis on profile were given for two bolts within outer medium pressure cylinder of one power plant. Combined with situation on the spot, conclusion was got that overlaying welding area exacerbated the uniformity of the bolt organizations, as well as changed isotropy of the bolt properties, created the conditions for the generation of cracks. The segregation of components and manufacturing residual defects also changed the isotropy of bolt properties to take further weakening of the local properties of bolt. They were main causes of bolt failure. And cylinders had deformed for design reasons during the use, where occurred outer opening what led to the change of the compression state of the bolt. It was the external cause of bolts failure.
出处
《华北电力技术》
CAS
2014年第2期14-19,65,共7页
North China Electric Power
