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本文研究了20Cr2Ni4A钢碳氮共渗层中残留奥氏体(A_R)对硬度、静弯强度、冲击韧性、耐磨损以及尺寸变形的影响。共渗淬火后,通过冷处理控制A_R量。试验证明,20Cr2Ni4A钢碳氮共渗后,表层的A_R对陈化稳定不敏感;冷处理过程中没发现明显的恒温马氏体转变;渗层中A_R量愈多其静弯强度和冲击韧性愈高,当最表层A_R量为20%(渗层中平均A_R量为31%)时,其耐磨性最佳;低温回火可提高耐磨性。试验还发现,这种钢碳氮共渗后,经-196℃深冷处理可获得HRC68的超高硬度,但其回火稳定性很差。
In this paper, the effects of retained austenite (A_R) on hardness, static bending strength, impact toughness, wear resistance and dimensional deformation of 20Cr2Ni4A steel were investigated. After permeation quenching, the amount of A_R is controlled by cold treatment. Experiments show that 20Cr2Ni4A steel after carbonitriding, surface A_R aging is not sensitive to the aging; cold treatment was not found significant temperature martensitic transformation; layer A_R the greater the amount of its static bending strength and impact toughness the higher , The wear resistance is best when the amount of A_R in the surface layer is 20% (the average A_R in the layer is 31%); and the tempering at low temperature can improve the wear resistance. The test also found that after this steel carbonitriding, HRC68 ultra-high hardness can be obtained after cryogenic treatment at -196 ℃, but the tempering stability is poor.