55NiCrMoV7钢的回火组织与性能

研究了 5 5NiCrMoV7钢在 10 0℃～ 70 0℃、90s～ 6 6 5h之间回火后的组织和硬度变化。结果表明 ,钢中的原奥氏体晶粒、马氏体板条不因回火过程而改变 ,回火析出碳化物的体积分数在一定回火温度、时间范围内保持恒定 ,但是碳化物的形态和尺寸随回火工艺而改变。钢的回火硬度与碳化物的等效直径、钢的弹性极限以及钢的弥散硬化密切相关。

55NiCrMoV7回火钢的组织定量分析

通过SEM、TEM、XRD、图像定量分析和维氏硬度测量,定量研究了55NiCrMoV7钢在100～700°C、90s～665h之间回火的组织和硬度变化.结果表明,钢中的原奥氏体晶粒、马氏体板条不因回火过程而改变,回火析出碳化物的体积分数在一定回火温度时间范围内保持恒定,但是碳化物的形态和尺寸随回火工艺而改变.

XRD Synchrotron Study of Carbide Precipitation in Martensitic Steels During Tempering

In order to improve the knowledge of the precipitation mechanism in martensitic steels containing carbon,XRD synchrotron experiments were performed. Firstly, the influence of Ni,Co and Al were studied and it was found that the precipitation of iron carbides occurs in same way as in Fe-C steel. However, with the addition of molybdenum and chromium in same steels, XRD synchrotron investigations clearly showed alloyed carbides directly precipitate, thereby preventing the iron carbides formation.