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在Gleeble-3500热力模拟机上对铸态42CrMo中碳低合金钢进行热压缩实验,利用金相显微镜(OM)、扫描电镜(SEM)以及电子背散射衍射(EBSD)技术分析热变形和880℃/2 h正火后的组织与微织构.实验结果表明:变形条件为1000℃/0.1 s-1时,在形变带和三叉晶界处新生再结晶晶粒,平均晶粒直径小;沿着< 001 >//ND分布旋转立方织构和立方织构;880℃/2 h正火过程中晶粒发生长大,晶粒内弥散分布碳化物颗粒,主要发生回复和静态再结晶,织构类型为立方织构和高斯织构.在1100℃/0.1 s-1条件下,晶粒尺寸较大,组织均匀,再结晶充分,大角度晶界占三分之二;织构组态为{001} <110>织构和沿着ξ-取向线的{110} <112>织构;正火后碳化物含量增加,珠光体片层间距减小,组织演变机制为高温回复与亚动态再结晶,织构类型表现为{110} <112>取向密度减小,旋转立方织构取向密度增大.

Hot compression test of a medium carbon low-alloy of as-cast 42CrMo steel was carried out on a Gleeble-3500 simulator.Microstructure and texture of the steel after water quenching and normalizing at 880 ℃ for 2 h were analyzed by OM,SEM and EBSD technique,respectively.The results indicate that the new recrystallization grains appear in deformation bands and triangle-boundaries,themean diameter of the grains is smaller in the condition of the deformation at 1000 ℃ with strain rate of 0.1 s-1.R-cube and cube texture is distributed along <001 >//ND.During normalizing at 880 ℃ for 2 h,the grains grow up and the carbide particles are distributed dispersively in the grains.The textures are mainly cube texture and Goss texture attributing to recovery and static recrystallization.When deformed at 1100 ℃,the large grains and homogeneous microstructure are obtained due to the fully recrystallization,leading to two the high-angle boundaries accounted for 2/3.Brass { 110} < 112 > along the ξ-fiber and { 001 } < 110 > dominate in the process.During the normalizing,the content of carbide increases and the inter-lamellar spacing of pearlite decreases.The mechanisms of microstructure development are recovery and meta-dynamic recrystallization at elevated temperature.The intensity of { 110} < 112 > is decreased,while the R-cube is increased.