Bearing steel hardness

Bearing steel is steel class quality requirement is very strict. Current requirement for bearing steel is put forward: the user free machining and inspection, improve the quality and specifications refine and improve the dimensional precision, and more and more importance on these requirements. To meet these requirements, JFE steel used various guarantee product quality and finish machining equipment production of bearing steel. These facilities and improve the quality of the development of the new technology, combining can produce wide size range, high quality and high added value of heat treatment and hot rolling bearing steel. The chemical composition of bearing steel steel grade CSiMnPSCrNiGCr150. 95 - 1. 050. 15 - 0. 350. 25 - 0. 45≤0. 025≤0. 0. 251. 40 - 1. 65≤0. 3GCr15SiMn0. 95 - 1. 050. 45 - 0. 750. 95 - 1. 25≤0. 025≤0. 0251. 40 - 1. 65≤0. Three purposes: GCr15: used for internal combustion engine, electric locomotives, machine tools, tractors, rolling mill, boring machine, mining general machinery, as well as high speed, high load mechanical ball, roller and shaft sleeve on the shaft rotates. GCr15SiMn: used for heavy duty machine tools, large machinery and there is no large impact load bearing of rolling mill. Heat treatment and hardness of the steel grade / ℃ isothermal annealing softening annealing temperature cooling hardness ( HB） Heating temperature / / ℃ ℃ isothermal temperature cooling hardness ( HB） GCr15790 - Furnace cooling 179-810 207790 - 810710 - Air cooling 207-720 229GCr15SiMn790- Furnace cooling 179-810 217790 - 810710 - Air cooling 207-720 229 steel grade is fire / ℃ high temperature tempering temperature cooling hardness ( HB） Temperature / ℃ hardness ( HB） GCr15900 - Air cooling 270-920 390650 - 700229 - 285 gcr15simn900 - Air cooling 270-950 390650 - 700229 - 285 steel grade / ℃ cooling quenching tempering temperature hardness ( HRC） Temperature / ℃ hardness ( HRC） GCr15860 oil cooling - 62 66150 - 17061 - 66 gcr15simn820 - Oil cooling 64150 - or 845 180≥62