论文部分内容阅读
结合显微组织分析、硬度测试等方法,对不同回火温度下40CrMnSiB钢电子束局部扫描后组织和性能进行研究。结果表明:由于快速的熔化-凝固过程,扫描区内晶粒细化形成淬硬层,其表面硬度比基体材料高出57.3%~65.9%,但脆化倾向明显;40CrMnSiB钢经电子束局部扫描后冲击吸收能量下降,整体抗冲击能力变差;随着回火温度升高,淬硬层与基体的硬度基本不变,但热影响层的硬度降低,同时冲击吸收能量降低幅度也变小,这与高温回火下马氏体结构转化有关,对断面形貌的SEM观察也证实这一结果。
Combined with microstructure analysis and hardness test, the microstructure and properties of 40CrMnSiB steel after partial scanning electron beam scanning electron microscopy were studied. The results show that due to the rapid melting-solidification process, the grain refinement in the scanning zone forms a hardened layer with a surface hardness 57.3% ~ 65.9% higher than that of the base material, but the embrittlement tendency is obvious. 40CrMnSiB steel is subjected to electron beam local scanning The impact energy absorbed after shock decreased, the overall impact resistance deteriorated; as the tempering temperature increases, the hardness of the hardened layer and the base of the same, but the heat-affected layer to reduce the hardness, while reducing the impact of absorption energy decreases, This is related to the transformation of martensite structure under high temperature tempering. SEM observation of the cross-section morphology also confirmed this result.