New technology of bearing steel heat treatment

New technology of bearing steel heat treatment ( 1) Austenite phase zone rolling technology; Finishing the control rolled in the austenite phase zone. The rolling technology for the foundation, after rolling product performance in general, all you need to do to post heat treatment. （ 2) Austenitic and austenite and carbide two hot rolling process; Austenitic and iron element in common existence Ar3 ~ Ar1 controlled rolling temperature range. In two phase zone controlled rolling in order to obtain more subtle is the purpose of the organization, in order to ensure the low temperature toughness under the premise of not reduce or slightly lower, make the strength of steel, especially the yield strength greatly increased, 3) Combined production of hot rolled and online spheroidizing annealing process; Refer to the red after rolling billet in single phase or two phase zone direct rolling technology for spheroidizing annealing. This process directly using the finished product keypad with appropriate cooling after rolling process, the ideal performance can be obtained, and can save energy and improve production efficiency. （ 4) Low temperature heating rolling technology; Cold rolling is heated to lower than conventional heating temperature of billet, rolling at lower than that of conventional hot rolling temperature, more specifically is medium temperature rolling, main purpose is to reduce required for billet heating energy consumption, reduce metal loss, reduce roll consumption, improve the product surface quality and fine grains, thus improving the performance of the products, can replace part of the product, heat treatment process. （ 5) Bearing steel cold deformation; High carbon steel bearing cold deformation plasticity pretreatment process, its characteristic is that it includes the following steps: 1) Heating: high carbon bearing steel workpiece heat blank to Ac1 ~ Accm; 2) Heat preservation, heat preservation time with high carbon steel bearing the effective thickness of the blank workpiece calculated: t = lDmin, type t is holding time, D is the effective thickness of the blank workpiece, the effective thickness of the unit is mm, l for heating coefficient, l = 1. 5 ~ 2. 0分钟/ mm; 3) Cooling: 7. Cool the cooling speed of 6 ℃ / min to 500 ℃, and then air cooling to room temperature. This process can effectively improve the heat treatment is blank after cold deformation and plastic ( 6) Isothermal rolling technology; Isothermal rolling technology is in the whole process of rolling finishing mill, namely the rolled piece into the finishing mill group they can maintain to the end of the rolling workpiece end temperature is consistent, have the online incubator ( Heating device) For thermal insulation of rolled piece. This process ensures the unity of the bearing cleaning rod comprehensive performance, expanding the scope of the varieties, can increase the volume weight.