Lewment55合金在高温浓硫酸中的腐蚀行为研究

Investigations into the Corrosion Behavior of Lewment 55 Alloy in Concentrated Sulphuric Acid at High Temperature

采用金相显微镜和Ｘ射线衍射相结合的方法，观察与分析了Ｌｅｗｍｅｎｔ５５铸造合金的金相组织，并测试了合金的均匀腐蚀、晶间腐蚀、点蚀和电化学腐蚀性能，研究了不同热处理制度对该合金的腐蚀行为的影响，从而确定了满足各项性能指标的最佳热处理制度。通过Ｌｅｗｍｅｎｔ５５合金与Ｃｒｌ７Ｎｉｌ７Ｓｉ５和Ｃｒｌ３Ｎｉ７Ｓｉ４不锈钢对比表明，Ｌｅｗ－ｍｅｎｔ５５合金在１２０℃，９８％Ｈ２ＳＯ４的介质中，具有较好的耐蚀性能。

The microstructure of Lewment 55 cast alloy was observed and analysed using optical microscope and X-ray diffraction spectrum, the properties in uniform corrosion, intergranular corrosion, pitting corrosion and electrochemical corrosion for Lewment 55 alloy were tested and the influence of different heat treatment conditions on corrosion behavior of the alloy was also studied, thus determining the best solution heat treatment process which allows the cast alloy to possess satisfactory properties. The comparison ofproperty of Lewment 55 versus Cr17Nil7Si5 and Cr13Ni7Si4 stainless steels showedthat the Lewment 55 alloy has better corrosion resistance in 98% H2SO4, solution at120C than that of Cr17Ni17Si5 steel.