Grinding Ability and Characteristics in Normal QT Heat Treatment vs. Carbo-nitriding Heat Treatment Bearing Steel under CBN Wheel Grinding Process

Abstract

For enhance fatigue resist ability in hardened bearing steel especially contaminated lubrication condition, Nitriding treatment applied. This diffuse nitrogen and carbon into the surface of steel during austenitizing. This enhanced surface condition gave physical strength with tribological function but this cause grinding difficulties in conventional grinding process. Its main reason is intensified toughness in the steel surface. Due to increase in Nitrogen and carbon in the steel surface, it contain more retained austenite than normal QT heat Treated condition. With grinding power trend it shows increasing in Nitriding condition. Also Same with grinding load behavior. Surface roughness slightly impaired in nitriding condition In roundness, QT treated condition shows conventional high speed adaptability but Nitriding Condition shows different behavior when accumulated wheel speed and depth of cut amount.