X10CrNiTi189钢高压蒸汽降温罐进气管断裂分析

THE FALURE ANALYSIS OF INLET GAS TUBE IN X10CrNiTi189 STEEL HPS DESUPERHEATING DRUM

应用光学显微镜、扫描电镜（ＳＥＭ）及凝液Ｃｌ－检测等方法对事故进气管进行分析。结果表明，该进气管断裂系由于应力腐蚀裂纹失稳扩展所造成。在本例高温高压纯水凝液介质中，其影响因素主要是应力，凝液中溶解氧的含量和材质的敏化程度等。对防护对策亦进行了探讨。

The failure of the inlet gas tube was investigated by using optical microscope. SEM and Cl - detection test. The results show that the failure of the tube is due to stress corrosion crack propagation. In the environment of high temperature high preesure and the liquid medium condensed by high pure water steam in this work, the failure of the tube is mainly related to the stress, the solved oxygen content in the condensed liquid and sensitivity degree of the tube material. According to the experiment results, means to prevent the tube failure have been suggested.