Analysis on modification behavior of rare earth to inclusions in GCr15 bearing steel
HAN Jie1, WANG Yi1, LIU Cheng-bao1, XU Rong-chang1, SUN Zong-hui1, LUAN Yi-kun2
1. Research Institute of SD Steel, Shandong Iron and Steel Co., Ltd., Jinan 271104, Shandong, China; 2. Shenyang National Laboratory for Materials Sciences, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, Liaoning, China
Abstract:In order to analyze the modification behavior rules of rare earth on inclusions in bearing steel, the modification behavior of different rare earth contents to inclusions in GCr15 bearing steel was investigated through industrial test, by means of scanning electron microscope, EDS analysis, non-destructive extraction of inclusions, ASPEX analysis, etc. The modification effect of rare earth on inclusions in steel varies greatly with the addition amount. It was found in production that addition of 0.015% rare earth plays a significant role in refining the larger inclusions. The inclusions are layered when 0.005% rare earth is added. When adding 0.003% rare earth, the proportion of rare earth in the inclusions is very small, and the effect of rare earth encapsulation is weakened. Research analysis shows that the oxide and sulfide inclusions of Al2O3, CaO, MgO, MnS and CaS in bearing steel can be effectively transformed into rare earth oxygen sulfide RE2O2S. The size of the inclusions is refined from 10 μm above to less than 5 μm, and the shape is spherical or elliptic.
YANG C Y, LUAN Y K, LI D Z, et al. Effects of rare earth elements on inclusions and impact toughness of high-carbonchromium bearing steel[J]. Mater Sci Technol, 2019, 35(8): 1298.
[14]
GAO J Z, FU P Z, LIU H W, et al. Effects of rare earth on the microstructure and impact toughness of H13 steel[J]. Metal, 2015(5): 383.
[15]
LIU H H, FU P X, LIU H W, et al. A novel large crosssection quencing and tempering mold steel matching excellent strength-hardness-toughness properties[J]. Mater Sci Eng A, 2018,737: 274.
MA Q, WU C C, CHENG G G. Characteristic and formation mechanism of inclusions in 2205 duplex stainless steel containing rare earth elements[J]. Materials Today Proceedings, 2015, 2(2): 300.
[42]
YIN N, CAI L J, HAI B L, et al. Effect of rare earth elements on the inclusion behavior in low alloy structural steel[J]. Materials Science Forum, 2019, 944(2): 364.