摘要
通过断口观察、化学成分分析、金相组织检查、硬度检测、拉伸及冲击试验等方法,对某大型锻造法兰脆性断裂原因进行了分析。结果表明:粗大的魏氏体组织是造成法兰发生脆性断裂的直接原因,阐述了粗大组织对法兰脆性断裂的影响机制;证明了这种组织缺陷与热处理时工件过热有关,可通过正确的正火工艺来消除,并且采用了正确的热处理工艺,材料的冲击功提高了2个数量级,解决了锻造法兰的脆性问题。
Failure analysis of a large forged flange was carried out by fracture observation, chemical composition analysis, metallurgical examination, hardness test, tensile test and impact test. The results show that coarse Widmanstatten structure is the direct cause of the flange brittle fracture. The effect mechanism of the coarse structure on brittle fracture was explained. This metallurgical defect was proved to be related to overheating in the final heat treatment process of flange and can be eliminated by appropriate normalizing process. Correct heat treatment process was adopted. And the impact energy of the material was improved by two orders of magnitude. Finally, the brittleness of the forged flange was solved.
出处
《失效分析与预防》
2012年第4期257-261,共5页
Failure Analysis and Prevention
关键词
法兰
失效分析
过热
低温脆断
魏氏组织
flange
failure analysis
overheating
low temperature brittle fracture
widmanstaten structure
