湿法生产硫酸氢钠晶体中蒸发器材质的耐蚀性评价

Evaluation on Corrosion Resistance of Evaporator Materials for Producing Sodium Bisulfate Crystal by Wet Process

为找到安全适用的湿法生产晶体硫酸氢钠工艺蒸发器材料,研究了不同条件下硫酸氢钠溶液对不锈钢(316L、2512、2545Mo、904L)、钛材(TA2)、非金属(石墨和玻璃钢)、合金(哈氏合金G30)等4类材料的腐蚀情况。结果发现:在常压条件下,分别于21.9%与40.0%的硫酸氢钠溶液中,恒浓度处理72 h,904L、哈氏合金G30、石墨及玻璃钢等4种材料耐腐蚀性能较好;在常压变浓度(21.9%~40.0%)和常压变浓度、搅拌条件下的溶液中连续处理72 h,4类材料的耐腐蚀性能均较好,但变浓度条件下腐蚀速度比恒浓度时快,搅拌状态下腐蚀速度比静态时快;在真空负压变浓度状态下连续处理72 h,904L及哈氏合金G30的表面有腐蚀,石墨及玻璃钢无明显腐蚀现象。

Aiming at the choice of evaporator materials for producing sodium bisulfate crystalline by wet process,the corrosion behavior of stainless steel(316 L,2512,2545 Mo,904 L),titanium(TA2),non-metal[graphite and fiber reinforced plastic(FRP)]and alloy(Hastelloy G30)materials under different conditions was studied.Results showed that under normal pressure conditions,the four materials were treated in 21.9%and 40.0%sodium bisulfate solution at a constant concentration for 72 h,904 L,Hastelloy G30,graphite and FRP materials had good corrosion resistance.The four materials were continuously treated for 72 h under normal pressure variable concentration(21.9%-40.0%)or normal pressure variable concentration and stirring condition,the corrosion resistance of the four materials was good,but the corrosion rate was faster under variable concentration condition than under constant concentration condition,and the corrosion rate was faster under agitation than under static state.The four materials were continuously treated under vacuum negative pressure for 72 h,and the surfaces of 904 L and Hastelloy G30 were corroded,whereas,graphite and FRP had no obvious corrosion.