Effect of Rare Earth Y on Mechanical Properties of GCr15 Bearing Steel

In order to explore the effect of rare earth Y on the mechanical properties of GCr15 bearing steel, GCr15 bearing steels with different Y contents were smelted by vacuum induction furnace. The effects of Y on the hardness, impact property, tensile property and inclusion of GCr15 bearing steel were studied by using MC010-HV-30Z Vickers hardness tester, SAN-ZBC2752A type impact testing machine, CSS-88500 type electronic universal testing machine, JSM-6510 type scanning electron microscope, and Sigma-300 field emission scanning electron microscope. The results show that when Y content is 0.005%, the test steel has good comprehensive mechanical properties.Y slightly reduces the hardness of GCr15 bearing steel from 258.7 HV to 254.4 HV. The impact energy increases by 17.9% from 17.9 J to 21.1 J. The tensile strength increases by 6.50% from 903.8 MPa to 963.3 MPa. The maximum tensile stress increases by 6.50% from 17.75 kN to 18.97 kN. The elongation after fracture increases by 16.80%. The fracture mode of the test steel transforms from intergranular fracture to transgranular fracture.After Y treatment, the inclusion size decreases from about 3 μm to about 1 μm.The hardness of the test steel decreases slightly, the impact energy, tensile strength and elongation after breaking increase somewhat, and the inclusion size decreases.