Cleanliness of GCr15 bearing steel refined by RH and VD vacuum processes
WEN Xin，REN Ying，ZHANG Lifeng
1.School of Metallurgical and Ecological Engineering， University of Science and Technology Beijing， Beijing 100083, China；2.School of Mechanical and Materials Engineering, North China University of Technology， Beijing 100144, China
Abstract：Abstract：The cleanliness of GCr15 bearing steels produced by RH and VD vacuum refining processes was compared. Evolutions of total oxygen (TO), total nitrogen (TN), total sulfur (TS), and inclusions were investigated. Bearing steel has high requirements for cleanliness. RH refining has advantages in reducing TO and TN content, removing solid inclusion, and circulating efficiency. After RH refining, the TO content in molten steel decreased by 61%, the TN content decreased by 15%, and the number density of inclusions decreased by 75%. The stirring of slag and steel was strong during the VD refining, which was beneficial to the desulfurization, the TS content in liquid steel decreased by 50%. The circulation rate of the liquid steel in the VD refining was much lower than that in RH refining. The stronger stirring of slag and steel during VD refining resulted in the slag entrainment. The contact angle between inclusions with different liquid phase fractions and liquid steel is different. Inclusions with liquid phase fraction less than 27% are not wetted with liquid steel and are easy to collide, grow and float up for removal, while the adhesion work of liquid inclusions is greater and difficult to remove from liquid steel.
温昕1，任英1，张立峰2. GCr15轴承钢RH和VD真空精炼过程钢洁净度对比[J]. 钢铁研究学报, 2022, 34(7): 613-621.
WEN Xin1，REN Ying1，ZHANG Lifeng2. Cleanliness of GCr15 bearing steel refined by RH and VD vacuum processes. JOURNAL OF IRON AND STEEL RESEARCH , 2022, 34(7): 613-621.
2022, Vol. 34 
