Abstract: The CCT curve of 100Cr6 bearing steel was measured by using thermal expansion instrument thermal simulation tester, metallographic microscope, field emission SEM,etc,it also studied the influence of thermal compression and controlled rolling and controlled cooling on network carbide precipitation behavior. The results show that: when the temperature of the secondary compression deformation decreases from 850 ℃ to700 ℃,the recrystallization refinement of austenite changes to non-recrystallization, and the secondary carbide gradually changed from closed network of grain boundary to semi-closed strip, short rod and then to chain along elongated austenite grain boundary, and the carbide was fine and dispersed in the range of 750-800 ℃.The Φ10 mm 100Cr6 wire adopts to control rolling and rapid cooling process from 910℃ to770 ℃. After hot rolling, spheroidal annealing and quenching and tempering, the carbide distribution uniformity is gradually improved, the austenite grain is refined from 8.0 grade to 10.0 grade, and the grain boundary carbide is trans- formed from closed mesh to discontinuous strip. The average thickness is reduced from 0.54 μm to 0.11 μm,and the network carbide level is reduced from33% of 3.0 grade to100% of 2.0 grade, which can shorten the spheroidizing annealing time and improve the fatigue life of bearings.

Key words: 100Cr6 Bearing Steel, CCT;Dynamic Phase Transformation;Controlled Rolling and Controlled Cooling, Network Carbide

摘要： 利用热膨胀仪、热模拟试验机、金相显微镜、场发射扫描电镜等测定了100Cr6轴承钢的CCT曲线，试验研究了热压缩及控轧控冷对网状碳化物析出行为的影响。结果表明：第二道次压缩温度从850℃降低至700℃时，奥氏体再结晶细化向未再结晶转变，二次碳化物逐步由晶界封闭网状向半封闭条状、短杆状再向沿拉长的奥氏体晶界链状转变，750～800℃内变形碳化物细小、分散；Φ10 mm 100Cr6线材采用910℃降至770℃温度控轧+快速冷却工艺，其热轧态、球化退火及淬回火后碳化物分布均匀性逐步提升，奥氏体晶粒由8.0级细化至10.0级，晶界碳化物由封闭网状向断续条状转变，平均厚度从0.54μm降低至0.11μm,网状级别由3.0级占比33%降低至≤2.0级占比100%,可缩短球化退火时间及提高轴承的疲劳寿命。

关键词: 100Cr6轴承钢；CCT, 动态相变；控轧控冷；网状碳化物