材料期刊网

采用Gleeble试验机模拟了10MnNiCr钢正火处理的连续冷却过程，观察了不同冷速下的显微组织，绘制了CCT曲线，测试了显微硬度和冲击功。结果表明：当该钢以0.167～15 ℃/s的速度冷却时，形成了M-A岛状组织；随着冷速提高，M-A岛附近的基体组织从粗大的多边形铁素体变为细化的贝氏体铁素体，岛的尺寸减小，与基体之间的硬度差值减小，冲击韧性改善。

The effect of cooling rate on the M-A constituents and mechanical properties in normalized 10MnNiCr steel was investigated using Gleeble simulation, microstructure observation and hardness and impact energy measurement. The results indicate that the island-like M-A constituents formed in the steel after normalization in an extensive range of cooling rate from 0.167 to 15o C/s. With the cooling rated increased, the polygonal ferrite as the matrix neighboring to the islands was replaced gradually by bainitic ferrite. This resulted in the morphological variation of island from large massive to small elongated ones. The improvement of impact toughness could be attributed to the decrease of microhardenss in M-A constituents and refinement of matrix phase as the cooling rate increased.