氨水储槽失效预测及跟踪调查

PROGNOSTICATING OF THE AMONIA VESSEL′S FAILURE AND CONTINUOUS INSPECTION OF THE FAILURE′S DEVELOPMENT

通过对氨水储槽近 4年工作历史跟踪 ,分析了此类容器在氨水环境中短期内发生失效泄露的原因。用X射线法对经热处理后的、新安装的氨水槽进行了较详细的应力测试 ,得出了残余应力较大、热处理效果不理想的结论。该氨水槽投产后不到一年 ,即出现裂纹 ,导致氨水泄漏 ,在使用的近 4年里 ,已发现 70余处泄漏点。对氨水槽的残余应力状况进行了复测 ,残余应力下降幅度约占 5 0 % ,但焊缝区的残余应力仍高于 0 .5σs。跟踪调查结果表明 ,氨水储槽的泄漏是多方原因造成的 ,包括原材料选择、热处理效果 。

The leakage and failure analysis of ammonia vessel is introduced in this paper. The vessel was established in 1998 and it worked in the ammonia environment for a short period. The vessel was detected by X-ray method in detail. The results showed that the residual stress is more high and the heat treatment is improper. In no more than one year since the vessel' being used, the cracks appeared in it, leading to the leakage of ammonia. For four years, there are more than seventy spots of leakage. The residual stresses of the vessel was inspected again in 2002, demonstrating that the residual stresses decreased by 50 percent and the stresses in the welding joints were still beyond 0.5σ s. The results of the two inspection showed that there are various factors of the leakage of the ammonia vessel, including the selection of the material, effect of the heat treatment and the large residual stresses, in which the larger residual stresses are the main reason.