冷却方式与时效温度对60NiTi合金硬度和组织的影响  

Effects of Cooling Methods and Aging Temperatures on Hardness and Microstructure of 60NiTi Alloy

作　　者：王子阳 左舜贵 王盖世 曹军 肖飞 WANG Ziyang;ZUO Shungui;WANG Gaishi;CAO Jun;XIAO Fei(School of Materials Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海工程技术大学材料工程学院,上海201620 [2]上海交通大学材料科学与工程学院,上海200240

出　　处：《轴承》2022年第5期46-50,55,共6页Bearing

基　　金：国家自然科学基金资助项目(51871151);上海市级大学生创新训练项目(CS2005006)。

摘　　要：系统研究了冷却方式、时效温度对60NiTi合金硬度和组织的影响,结果表明:相比于退火处理试样,正火或淬火处理能显著提高合金的硬度;正火试样300℃时效处理能进一步提高合金硬度,而400,500,600℃时效处理使合金硬度降低,其中600℃时效处理合金硬度下降最显著;通过正火+300℃时效处理后合金的硬度由铸态试样的31 HRC提高到60 HRC。金相与X射线衍射(XRD)结果表明,正火和淬火处理后的60NiTi合金晶粒中没有粗大针状析出相形成。获得均匀细小的组织并避免Ni_(4)Ti_(3)相在冷却及时效过程中粗化并转变成Ni_(3)Ti相是得到高硬度60NiTi合金的关键。The effects of cooling methods and aging temperatures on microstructure and hardness of 60 NiTi alloy are systematically studied.The results show that:the normalizing or quenching treatment increases the hardness of the alloy notably as compared to annealing.Aging at 300 °C further increases the hardness of normalized samples,while aging at 400,500 and 600 ℃decreases the hardness,the most significant reduction in hardness is observed in 600 ℃-aged samples;the hardness of the alloy increases from 31 HRC for as-cast samples to 60 HRC after normalizing and 300 ℃aging treatment.The metallographical and XRD results show that no coarse needle-like precipitates are formed in grain of 60 NiTi alloy after normalizing and quenching.Obtaining a uniform and fine microstructure as well as avoiding the coarsing and transformation of Ni_(4)Ti_(3) phase to Ni_(3)Ti phase during cooling and aging is the key to obtain the 60 NiTi alloy with high hardness.

关 键 词：滚动轴承 60NiTi 时效处理 硬度 马氏体相变 

分 类 号：TH133.331[机械工程—机械制造及自动化] TG166.5[金属学及工艺—热处理]