固溶和时效处理对高锰低镍不锈钢组织与性能的影响

Effect of solution and aging treatment on microstructure and properties of high manganese low nickel stainless steel

以新型高锰低镍不锈钢为研究对象,研究了不同固溶和时效处理温度对其组织和性能的影响。结果表明,退火态和固溶态高锰低镍不锈钢均为单一奥氏体组织,随着固溶温度的提高,晶粒不断长大,析出物不断溶入材料基体,使材料强度和硬度不断降低,1050℃固溶处理后析出物基本上已全部固溶,此时抗拉强度为1016 MPa,伸长率和断面收缩率分别为67.43%和53.6%,此时塑性最好,故高锰低镍不锈钢的最佳固溶温度为1050℃。固溶+时效处理后高锰低镍不锈钢中的析出物主要为Cr的碳氮化物和Mn的硫化物,在750℃时效处理后析出物含量达到峰值,强度和硬度达到最高,故750℃为其最敏感析出温度。超过750℃析出物数量减少,850℃时材料塑性最好。

Effects of solution and aging temperature on microstructure and properties of a new type high manganese low nickel stainless steel were studied.The results show that the microstructure of annealed and solution treated high manganese low nickel stainless steel are composed of a single phase austenite.With the increase of solution temperature,the grain grows and precipitates dissolve into the matrix,which makes the strength and hardness of the material decrease continuously.After solution treated at 1050℃,all precipitates have been dissolved,meanwhile,the tensile strength is 1016 MPa,elongation and reduction of area are 67.43%and 53.6%respectively,and the plasticity is the best.Therefore,the best solution temperature of the high manganese low nickel stainless steel is 1050℃.Moreover,the precipitates in the high manganese low nickel stainless steel are mainly Cr carbon nitride and Mn sulfide after solution an aging treatmant.After aging at 750℃,the content of precipitates reaches the peak,and the strength and hardness reach the highest.Therefore,750℃is the most sensitive precipitation temperature of the high manganese low nickel stainless steel.When the aging temperature is above 750℃,the content of precipitates decreases,and the plasticity of the material is the best when aged at 850℃.