9Ni钢乙烯球罐的应力分析及裂纹研究

Analyses of Tension and Studies of Crack for Globose Tank of Ethylene of 9Ni Steels

对９Ｎｉ钢乙烯球罐进行了应力分析和裂纹扩展研究，给出了几种理论所计算的临界裂纹尺寸，并指出造成球罐产生裂纹的原因众多。最常见有冷致裂纹和应力状态下氨致腐蚀裂纹，以及残余应力、温度应力或几种应力叠加等所产生的裂纹。绘出了９Ｎｉ球罐水压试验压力与最大应力点应力的关系图，并推荐贮存压力为１．４ＭＰａ（表压），对此球罐的最大应力点应力≤３．３３ＭＰａ。

In this paper,the analyses of tension and the studies of crack expansion for globose tank of 9Ni steels have been performed.The critical sizes of the crack have been calculated according to some theories.There are many reasons for the producing of crack in the globose tank,the most common reasons are cold,corrosion by hydrogen at tension state,remaining tension,heat tension or the pile of them. The relation between the pressu-re of water pressure test and the tension at the maximum tension point has been given, when the storing gauge pressure is 1.4MPa, the maximum tension of the globose tank is less than 3.33MPa.