α-Cr相对新型奥氏体合金热处理组织及性能的影响  

Influence of α-Cr phase on new kind of austenitic alloy heat treatment organization and performance

作　　者：杨金文[1,2] 周旺松 陆建生[1] 俞峰[2] 许达[2] 曹文全[2] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]钢铁研究总院特殊钢研究所,北京100081 [3]西安建筑科技大学冶金工程学院,陕西西安710055

出　　处：《钢铁》2015年第7期84-91,共8页Iron and Steel

基　　金：北京教委共建资助项目(教13T60890)

摘　　要：对新型奥氏体轴承材料GNiCr40Al3Ti进行固溶-时效处理,采用扫描电镜、金相显微镜和洛氏硬度计等分析手段,研究了固溶温度对其组织和性能的影响。结果表明,固溶温度越高,残留的α-Cr相粒子也越少,固溶效果越好,晶粒尺寸增加,固溶硬度下降。固溶过程主要受铬元素在基体中的扩散所控制,扩散激活能ΔG为（443±37）kJ/mol。时效后α-Cr相颗粒的平均尺寸基本保持在1.6μm,大部分的α-Cr相颗粒尺寸分布在0.5-2.0μm的范围内;固溶-时效后GNiCr40Al3Ti合金的硬度主要受固溶阶段基体溶解α-Cr相颗粒的程度影响,时效硬度最高达到61.5HRC。根据试验与分析结果,GNiCr40Al3Ti合金的固溶温度应不低于1150℃,以满足高硬度及良好机加工性能。The effects of solid solution and aging treatment on the microstructure and hardness were studied through the combination of TEM,optical microscope and Rockwell hardness. Results indicated that the increase of the solid solution temperature would result in the decrease of the volume fraction of a-Cr phase,refining the grain size and lowering of the hardness and. The solid solution treatment was mainly controlled by the bulk diffusion of Cr in the austenite with a diffusion activation energy of（443±37）kJ/mol. After aging,the a-Cr particle size ranged from 0.5-2.0 μm with average value of about 1.6 μm. The hardness of the alloy after aging was mainly determined by the quantity of α-Cr in the matrix,which could give 61.5HRC in the maximum. Based on the study of the solution and aging treatment,it was proposed that solid solution temperature of GNi CRr40Al3 Ti should be higher than 1 150 ℃ to fulfill its high hardness and machining requirement.

关 键 词：奥氏体合金 固溶 时效 显微组织 硬度 

分 类 号：TG161[金属学及工艺—热处理] TG142.1[金属学及工艺—金属学]