【摘要】 对由Cr5支承辊(锻后热处理态)截取的冲击试样进行不同回火温度的调质处理。运用扫描电子显微镜和洛氏硬度计对冲击后试样进行断口、金相显微组织(调质处理前后)的观察和硬度检测。结果表明,调质处理后试样的显微组织得到显著改善,与锻后热处理态相比,调质处理后组织中的碳化物更加细小,并且弥散分布于基体上;随回火温度的升高,碳化物有聚集粗化倾向;断口形貌由准解理和撕裂棱向韧窝过渡;冲击吸收能量升高,硬度降低。回火温度为540℃左右时,Cr5钢材料有较好的综合力学性能。更多还原

【Abstract】 Under different tempering temperature,the quenching and tempering for in impact test specimens intercepted in Cr5 backup roll( with heat treatment after forging was carried out). Fracture morphology of impacted specimens,metallographic microstructures( before and after quenching-and-tempering) and hardness were observed and tested. Results show that the microstructures of specimens after quenching and tempering have been improved significantly. Compared with as-postforging heat treating carbides are more refine and dispersedly distributed in the matrix. With the increase of tempering temperature,carbides have the tendency to aggregation and coarsening,fracture morphology transit from quasi-cleavages and tear ridges to dimples. Impact absorbed energy increases and hardness reduces. The better comprehensive mechanical properties could be obtained when tempering temperature is about 540 ℃.更多还原