镍铬轴承合金固溶时效态组织特征与力学性能  

Microstructure and mechanical properties of Ni-Cr bearing alloy in solution aging treatment

作　　者：杨晨星 吴志伟 杨卯生[2] 赵昆渝[1] YANG Chen-xing;WU Zhi-wei;YANG Mao-sheng;ZHAO Kun-yu(Faculty of Material Science and Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;Institute for Special Steel,Central Iron and Steel Research Institute,Beijing 100081,China)

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

出　　处：《钢铁研究学报》2020年第3期242-252,共11页Journal of Iron and Steel Research

摘　　要：研究了00Cr40Ni55Al3Ti轴承合金固溶态和时效态的组织特征及硬度变化规律。结果表明:随着固溶温度的升高,α-Cr相析出数量呈下降趋势,在1 200℃时α-Cr相尺寸最小,面积分数仅为8.45%;高于1 200℃时,α-Cr相尺寸逐渐增大,数量减少。固溶处理后冷却速度越快,α-Cr相析出数量越少,硬度降低;固溶温度在1 190~1 210℃之间以138℃/s进行冷却,经600℃×6 h时效处理后,硬度超过59.7HRC,合金微观组织主要由球状α-Cr相和均匀片层组织及弥散分布其中的纳米级γ′相组成,硬度较为均匀。1 200℃固溶处理以138℃/s进行冷却,经550℃保温6 h后,00Cr40Ni55Al3Ti合金显微组织为球状α-Cr相、片层组织和非片层组织,非片层组织面积分数约为32.21%,片层组织硬度达703HV,非片层组织硬度为249HV;当时效温度为600和650℃时,时效时间在5~7 h范围内,显微组织为均匀分布的片层组织和球状α-Cr相,硬度为676HV^712HV。00Cr40Ni55Al3Ti轴承合金在1 190~1 210℃之间进行固溶处理后快速冷却(冷却速度大于138℃/s),经600℃时效处理6 h后,洛氏硬度可达到60HRC以上。Microstructure and hardness of 00 Cr40 Ni55 Al3 Ti bearing alloy during solution and aging were studied. The results show that the amount of precipitation of α-Cr phase decreases with the increase of solution temperature. The size of α-Cr phase is the smallest and the area percentage is only 8.45% at 1 200 ℃. When the temperature is higher than 1 200 ℃, the size of α-Cr phase increases gradually and the number decreases. The faster the cooling rate is after solution treatment, the less the precipitation of α-Cr phase is and the lower the hardness is. The solid solution temperature was cooled at 138 ℃/s between 1 190-1 210 ℃ after 600 ℃×6 h aging treatment, and the hardness is above 59.7 HRC, with the microstructure mainly composed of spherical α-Cr phase and uniform lamellar structure and nano-scale γ’-phase dispersed therein, and the hardness is relatively uniform. When the cooling speed is 138 ℃/s after 1 200 ℃, followed by aging at 550 ℃ for 6 h, the microstructures of 00 Cr40 Ni55 Al3 Ti alloy are spherical α-Cr phase, lamellar structure and non-lamellar structure. The non-lamellar area percentage is 32.21%. The lamellar structure hardness and the non-lamellar structure are 703 HV and 249 HV respectively. When the aging temperature is 600 ℃ and 650 ℃ and the aging time is in the range of 5-7 h, the microstructure is uniformly distributed lamellar structure and spherical α-Cr phase and the hardness is 676-712 HV. The heat treatment process of 00 Cr40 Ni55 Al3 Ti bearing alloy is as follows:the solution temperature is between 1 190-1 210 ℃, the cooling rate is not less than 138 ℃/s, the aging temperature is 600 ℃, the aging time is 6 h. The hardness of the alloy is above 60 HRC.

关 键 词：固溶处理 时效处理 γ′相 硬度 

分 类 号：TG162.71[金属学及工艺—热处理]