Stainless steel bearings after heat treatment technology application effect of 31)

Stainless steel bearings after heat treatment technology application effect of stainless steel after heat treatment technology of the application effect of bearing, only through constant test will have the conclusion. Here are after thousands of experiments by me and come out the result. ( 1) To expand the application range generally GCr15 bearing steel GCr15 steel M when quenching ring effective wall thickness under 12 mm, but when the BL quenching by nitrate cooling ability is strong, if use the measures, such as stirring, string move, add water ring effective wall thickness can be expanded to about 28 mm. ( 2) Hardness is stable, good uniformity of the BL change is a slow process, generally GCr15 steel 4 h, GCr18Mo steel need 5 h, ring in long isothermal nitrate, on the surface of the core organization transformation almost simultaneously, so the bearing stiffness stability, uniformity, good general BL GCr15 steel after quenching hardness in 59 ~ 61 HRC, uniformity & le; 1 HRC, unlike M quenching ring wall thickness slightly bigger when there is low hardness, soft point, poor uniformity. ( 3) Reduce quenching and grinding cracks in rail, rolling mill bearing production, because the ring size, weight, oil quenching M the organization brittleness is big, to obtain high hardness after quenching is often strong cooling measures, as a result, quenching cracks; And BL quenching, because is much better than M BL organization toughness, surface formed up to at the same time 400 - - 500 mpa compressive stress, greatly reducing the quenching crack tendency [ 19] ； When grinding surface compressive stress to offset some of the stress, makes the overall stress level drops, greatly reducing the grinding crack. ( 4) Improve the service life of bearing to bear large impact load of railroad, rolling mill bearing stainless steel, etc. , after M quenching when using main failure forms is: inner sleeve cracking when assembling, use in the process of impact outer ring, inner ring fracture, falling guard and isothermal quenching bearing with good impact toughness, surface compressive stress, whatever the assembly inner sleeve craze, or using Chinese and foreign set of guard metal shed and inner sleeve fracture tendency is greatly reduced, and can reduce the edge stress concentration of roller. Therefore, after isothermal quenching than M after quenching the average life expectancy and improve reliability