固溶处理温度对2507双相不锈钢组织结构及耐蚀性能的影响

【目的】现代工业的飞速发展对双相不锈钢的使用要求越来越高,为扩大2507双相不锈钢(DSS2507)的实际应用,本研究探讨固溶处理温度对DSS2507组织结构、硬度及耐蚀性能的影响。【方法】通过定量金相法及硬度法研究固溶处理温度对DSS2507显微组织结构以及硬度的影响;通过电化学实验分析固溶处理温度对DSS2507抗腐蚀能力的影响。【结果】随着固溶处理温度的上升,铁素体α相含量增多而奥氏体γ相含量减少,固溶处理温度为1 050~1 100℃时可使钢中铁素体相跟奥氏体相的比例达到1∶1。固溶处理温度为1 000~1 050℃时DSS2507的硬度降低;但固溶处理温度从1 050℃升高到1 200℃时,其硬度又逐渐升高。另外,随着固溶处理温度从1 000℃升高到1 200℃,DSS2507的耐均匀腐蚀和点蚀性能先增强后减弱,1 050℃处理的DSS2507抗电化学腐蚀性能最优。【结论】固溶处理温度为1 050~1 100℃时可以使DSS2507两相比例达到1∶1,经1 050℃固溶处理的DSS2507抗电化学腐蚀性能最优。

Effect of Solution Treatment Temperature on Microstructure and Corrosion Resistance of 2507 Duplex Stainless Steel

[Objective]With the rapid development of modern industry,more and more require-ments are put forward for the use of duplex stainless steel.Therefore,in order to enlarge the applicable range of 2507 duplex stainless stell (DSS2507),the research investigated the effect of solution treatment temperature on the microstructure,hardness and corrosion resistance of DSS2507.[Methods]We used quantitative metallography and hardness methods to study the effect of solution treatment temperature on the microstructure and hardness;in addition, used electrochemical tests to study the effect of solution treatment temperature on corrosion resistance of DSS2507.[Results]Quantitative metallographic analysis showed that with the solution treatment temperature rising,alpha phase content increased and the content of aus-tenite phase reduced.When solution treatment temperature was 1 050℃ to 1 100℃,phase proportion of ferrite phase and austenitic phase reached 1∶1;when solution treatment tempera-ture was 1 000℃ to 1 050℃,hardness of DSS2507 decreased;when solution treatment temperature increased from 1 050℃ to 1 200℃, hardness increased gradually.Electrochemical tests showed that with the solution treatment temperature increasing from 1 000℃ to 1 200℃,uniform corrosion resistance and pitting cor-rosion resistance of DSS2507 increased firstly and then decreased,when the solution treat-ment temperature was at 1 050℃,the sample had the best electrochemical corrosion resist-ance.[Conclusion]When the solution treatment temperature was 1 050-1 100℃,the two-phase ratio could reach 1∶1,and when the solution treatment temperature was at 1 050℃, the sample had the best electrochemical corrosion resistance.