摘要
对失效件进行了化学成分、宏观断口与金相组织分析,对筒体组合件进行了温度场模拟实验和结构应力分析。从而得出事故发生的过程与原因,认为高的二次应力与沿晶析出大量σ脆性相是拉筋角焊缝早期断裂的主要原因,而这又是承压壳体短时超温过载破坏的先决条件。
The chemical composition analysis, macro-fraetography and metallography analysis were carried out for the failure parts. The simulating tests of the temperature field and structure stress analysis of the shell were performed. From the analysis and study of the results above, the process and causes of the accident have been deduced. The authors consider that the high secondary stress and a great amount of brittle σ phase separated out along the grain-boundaries are the main causes of the early failure of the welds between the inner shell and the cone shell, and this can, in turn, lead to the failure of the pressured shell.
