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制定了两种不同的热处理工艺,研究18Cr2Ni4WA钢真空渗碳后回火、淬火和深冷工艺对材料组织和性能的影响。结果表明,18Cr2Ni4WA钢渗碳后,经高温回火、淬火、深冷和低温回火处理后,渗碳层深度几乎不受影响,表面残留奥氏体含量显著降低。经680℃×5 h两次高温回火+860℃淬火+-115.3℃深冷+160℃低温回火工艺处理后,试样表面硬度为64.2 HRC,渗碳层深度为0.86 mm;并得到由针状回火马氏体、少量残留奥氏体和弥散分布的点状碳化物组成的渗碳层组织和由低碳板条状回火马氏体组成的心部组织,不仅使得表面获得高硬度,同时保证了心部的强韧性。
Two different heat treatment processes were developed to study the effect of tempering, quenching and cryogenic processes on microstructure and properties of 18Cr2Ni4WA steel after vacuum carburizing. The results show that after carburizing 18Cr2Ni4WA steel, after tempering at high temperature, quenching, cryogenic and low temperature tempering, the depth of carburized layer is almost unaffected and the retained austenite content on the surface decreases significantly. After 680 ℃ × 5 h twice high temperature tempering + 860 ℃ quenching + -115.3 ℃ cryogenic + 160 ℃ low temperature tempering process, the sample surface hardness of 64.2 HRC, depth of carburized layer of 0.86 mm; and obtained by Needle-shaped tempered martensite, a small amount of retained austenite and dispersed distribution of carbides composed of carbides and hearths consisting of low-carbon lath tempered martensite not only made the surface high Hardness, while ensuring the strength of the heart.