热处理对经济型高碳马氏体不锈钢J50Cr13组织和硬度的影响

对高碳马氏体不锈钢J50Cr13进行不同淬火温度、不同冷却方式的热处理,通过光学显微镜(OM)观察、X射线衍射(XRD)分析及硬度试验对试验钢进行组织和硬质分析。结果表明,随淬火温度的升高,马氏体组织变粗大,残留奥氏体含量增加,碳化物逐渐溶解入基体;淬火温度为990~1080 ℃时,水冷和空冷试验钢的硬度值均随淬火温度的升高而增加,淬火温度由1080 ℃升高至1110 ℃时,试验钢的硬度值降低。990 ℃淬火时,水冷处理和空冷处理的硬度值相差最大,达3 HRC;淬火温度升高,两种冷却方式对试验钢的硬度影响变小;淬火温度为1110 ℃时,两种冷却方式的硬度值几乎相同。J50Cr13高碳马氏体不锈钢的最优淬火温度为1080 ℃,冷却方式为水冷。

Effect of heat treatment on microstructure and hardness of economic high carbon martensitic stainless steel J50Cr13

High carbon martensitic stainless steel J50Cr13 was treated with different quenching temperatures and cooling modes. Microstructure and hardness of the tested steel were analyzed by optical microscope observation (OM), X-ray diffraction (XRD) analgss and hardness test. The results show that, with the increase of quenching temperature, the martensite structure coarsens, the content of retained austenite increases, and the carbides gradually dissolve into the matrix. With the increase of quenching temperature in 990-1080 ℃, the hardness values of both the water-cooled and air-cooled tested steel specimens increase; while when the quenching temperature increases to 1110 ℃ from 1080 ℃, the hardness values decrease. When quenched at 990 ℃, the difference between the hardness values of water-cooled and air-cooled specimens is the largest and up to 3 HRC, and when the quenching temperature increases, the effect of cooling on the hardness of the tested steel becomes less. When the quenching temperature is 1110 ℃, the hardness values of the water-cooled and air-cooled specimens are almost the same. The optimal quenching temperature of the J50Cr13 high carbon martensitic stainless steel is 1080 ℃, and then water cooling.