摘要
高端滚动轴承在服役过程中存在的尺寸稳定性差和滚动疲劳寿命低等问题,严重制约着我国高端装备制造业的发展水平。因此,急需开发具有高强韧性、耐磨、耐疲劳特性的轴承钢。中碳轴承钢作为超高速高精密滚动轴承极具潜力的轴承钢材料,对不同工艺条件下的中碳合金钢ECAP(equal channel angular pressing)工艺参数开展研究,分析了ECAP过程对42CrMo钢的挤压载荷、等效应变、等效应力及温度场数值变化和分布规律。研究结果表明,适当提高挤压初始温度和挤压速度,均可以有效降低挤压载荷和等效应力;加大挤压速度可以明显提升试件挤出温度,但不利于试件ECAP过程形变的均匀性;减小摩擦系数可以显著降低挤压载荷,有助于提高晶粒细化的均匀程度。综合考虑,选定挤压温度950℃,挤压速度10 mm/s、摩擦系数0.03条件下设计试验,可以有效提高ECAP细化晶粒的能力,同时为试件进行下一步热处理提供良好初始条件。以上试验研究是对中碳钢细晶强化的全新探索,可以为其他性能相近的金属材料开展ECAP研究提供技术参考。
The problems of poor dimensional stability and low rolling fatigue life in the service process of high-end rolling bearings,which seriously restrict the development level of our country’s high-end equipment manufacturing industry,it is urgent to develop bearing steel with high strength,toughness,wear resistance and fatigue resistance.Medium carbon bearing steel is a promising bearing steel material for ultra-high-speed and high-precision rolling bearings,this paper studies the equal channel angular pressing(ECAP)process parameters of medium carbon alloy steel under different process conditions,and analyzes the numerical change and distribution law of the extrusion load,equivalent strain,equivalent stress and temperature field of 42CrMo steel in the ECAP process.The research results show that the extrusion load and equivalent stress can be effectively reduced by appropriately increasing the extrusion initial temperature and extrusion speed;increasing the extrusion speed can significantly increase the extrusion temperature of the specimen,but it is not conducive to the uniformity of the deformation of the specimen during the ECAP process;reducing the coefficient of friction can significantly reduce the extrusion load,helping to improve the uniformity of grain refinement.Comprehensive consideration,the design experiment is selected under the conditions of extrusion temperature of 950℃,extrusion speed of 10 mm/s and friction coefficient of 0.03,which can effectively improve the ability of ECAP to refine grains and provide good performance for the next heat treatment of the specimen and initial conditions. The above experimental research is a new exploration of the grain refinement strengthening of medium carbon steel, which can provide a good reference for the ECAP process of other metal materials with similar properties.
作者
李万鹏
王建梅
郑晓华
王强
吉宏斌
LI Wan-peng;WANG Jian-mei;ZHENG Xiao-hua;WANG Qiang;JI Hong-bin(Engineering Research Center of Heavy Machinery Ministry of Education,Taiyuan University of Science and Technology,Taiyuan 030024,China)
出处
《重型机械》
2023年第2期25-32,共8页
Heavy Machinery
基金
国家自然科学基金重点项目(52035006)
山西省新兴产业领军人才资助项目。
关键词
ECAP
中碳合金钢
工艺参数
数值模拟
42CrMo
equal channel angular pressing(ECAP)
medium carbon alloy steel
process parameters
numerical Simulation
42CrMo
