大型阀门的结构设计及堆焊层耐腐蚀性能的研究

发布时间：2018-01-11 05:31

本文关键词：大型阀门的结构设计及堆焊层耐腐蚀性能的研究　出处：《沈阳工业大学》2013年硕士论文　论文类型：学位论文

【摘要】：每年由于阀门的泄露造成财产损失，危及安全的事件时有发生。造成化工行业中阀门泄露的原因之一就是阀门开关失灵，针对这种情况，本文设计了一种双重开关控制结构，加强阀门的安全性能。另一个造成泄露的主要原因是阀门长时间的受到内在溶液的腐蚀，比如受到硫酸溶液、磷酸溶液、硝酸溶液等长时间的腐蚀，就会发生上述情况。奥氏体不锈钢具有良好的抗酸腐蚀性，如超奥氏体不锈钢，具有良好的抗酸腐蚀性能。但其价格昂贵，尤其是在一些大型的阀门上，，若都用超奥氏体不锈钢当做原材料势必会造成浪费。本文意在现有的大型低碳钢阀门的基础上，堆焊奥氏体不锈钢焊条来提高阀体内表面的耐腐蚀性能,延长其使用寿命。本文对一些常见奥氏体不锈钢焊条A022、A102、A137、A302、A312、A402的堆焊层，自制的加Si型不锈钢焊条的堆焊层，以及母材Q235进行了耐酸腐蚀性能，耐磨性能的对比分析。极化曲线实验结果表明在4mol/L的硫酸溶液中以及4mol/L的磷酸溶液中，耐酸腐蚀性最差的是基体Q235，堆焊层耐酸腐蚀性能最好的是A402焊条。在4mol/L的硝酸溶液中耐酸腐蚀性最差的是基体Q235，堆焊层耐酸腐蚀性能最好的是加硅型焊条。盐雾腐蚀实验结果表明，耐氯离子腐蚀性能最差的是Q235，堆焊层耐氯离子腐蚀性能最好的是A402焊条。摩擦磨损实验结果表明，堆焊层耐磨性能最好的是A402，耐磨性能最差的是加硅焊条。本文对焊接过程进行了有限元模拟，发现焊接电流与焊接电压越大，焊后残余应力越大。
[Abstract]:One of the reasons for valve leakage in chemical industry is valve switch failure. In this paper, a double switch control structure is designed to enhance the safety performance of the valve. Another major cause of leakage is the corrosion of the valve by internal solution for a long time, such as sulfuric acid solution, phosphoric acid solution. The austenitic stainless steel has good acid resistance, such as ultra austenitic stainless steel, but its price is high. Especially in some large valves, the use of ultra-austenitic stainless steel as raw materials will be wasteful. The austenitic stainless steel electrode is surfaced to improve the corrosion resistance of the inner surface of the valve body and prolong its service life. This paper deals with some common austenitic stainless steel welding electrodes A022A102 and A137A302. The acid corrosion resistance and wear resistance of A312A402 surfacing layer, self-made surfacing layer of Si-type stainless steel electrode and base metal Q235 were compared and analyzed. The results of polarization curves show that Q235 is the most acidproof in 4 mol / L sulfuric acid solution and 4 mol / L phosphoric acid solution. A402 electrode is the best in acid corrosion resistance of surfacing layer. Q235 is the worst acid corrosion resistance in 4 mol / L nitric acid solution. The acid corrosion resistance of the surfacing layer is the best, and the salt spray corrosion test results show that Q235 is the worst corrosion resistance of the surfacing layer. The best corrosion resistance of the surfacing layer is the A402 electrode. The results of friction and wear test show that the best wear resistance of the surfacing layer is A402. The welding process is simulated by finite element method. It is found that the greater the welding current and voltage, the greater the residual stress after welding.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TG455;TH134

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