The bearing steel GCr15 austenitized at different temperature is studied,and the different proportions of (M + Bl) duplex structure are got under different isothermal quenching temperature and isothermal time.The influence of carbide on strength and toughness is explored.The experimental results show that with the increase of austenitizing temperature,the residual carbide gradually gets smaller,uniform and dispersion.As the isothermal time prolonged,the lower bainite is developed from isolated single needle to needle grass,side-by-side or pile.When the amounts of lower bainite are 50％ ～ 60％,its bending strength is higher than the conventional quenching,and the deflection is significandy improved.%研究了GCr15轴承钢在不同温度奥氏体化后,以不同等温淬火温度和等温时间获得的不同比例的马氏体+下贝氏体(M+Bl)复相组织,探讨了碳化物对其强韧性的影响.试验结果表明,随着奥氏体化温度的提高,残余碳化物逐渐细小、均匀、弥散,随着等温时间延长,下贝氏体针由孤立单针状向草丛、并排或堆状发展;当下贝氏体量为50％～ 60％时,其抗弯强度和挠度均比常规淬火高,挠度提高尤为显著.
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