(1) expanded GCr15 steel application scope, generally GCr15 steel M hardened effective wall thickness in collar 12 mm the following, but because XiaoYan BL quenching cooling ability strong, if the stirring, dynamic and measures of water, rings the effective wall thickness can be expanded to 28 mm or so.

(2) hardness stability, good uniformity BL change because is a slow process, general GCr15 steel need 4 h, GCr18Mo steel need 5 h, long time XiaoYan rings in isothermal, surface microstructure transformation of heart almost at the same time, so the hardness stability, good uniformity, general GCr15 steel BL after quenching in 59-61 hardness HRC, uniformity than 1 HRC, don't like hardened wall thickness slightly bigger rings appeared low hardness, soft point, uniformity poor etc.

(3) decrease quenching, grinding crack in the railway, rolling mill bearing production, the size, weight heavy rings, oil hardened M organization brittleness is big, to make harden get high hardness often take strong cooling measures, the result of micro cracks quenching; And BL quenching, as the BL organization than M organization toughness good much the same surface formation as high as 400-500 MPa pressure stress, greatly reducing the quenching cracking tendency; In the grinding process surface compressive stresses to offset the grinding of stress, make whole stress levels drop, greatly reducing the grinding crack.

(4) bearing service life to improve bear large impact load of railway, rolling mill bearing, etc., the M hardened when using main failure form for: when the assembly of inner sleeve craze, use process by shock raised edge DiaoKuai, inner circle between fracturing, and because the isothermal quenching bearing impact toughness, good surface compressive stress, no matter when the assembly of inner sleeve craze, or use process of Chinese and foreign DiaoKuai raised edge, in the set of fractured greatly decreased orientation, and can reduce the edge of roller stress concentration. Therefore, after the isothermal quenching than M after quenching average life expectancy and reliability.
 



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