固溶和时效处理对高锰低镍不锈钢组织与性能的影响

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。

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

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 ℃.