高速钢轧辊表面氧化行为的原位观察

采用 VL2000DX-SVF18SP型超高温激光共聚焦显微镜原位观察了高 V高速钢的氧化行为，并与采用 NETZSCHSTA449C型示差扫描量热仪 /热重（DSC/TGA）连续加热过程氧化增重进行了对比。结果表明：高 V高速钢的组织由分布在马氏体基体上的含 V的 MC型球形碳化物及 Cr、Mo为主的 M7C3和 M6C型共晶碳化物构成。高速钢在连续加热过程中，当温度低于 480℃时，随温度增加，几乎不氧化；当温度高于 480℃时，氧化速度随温度升高显著增加；当温度高于 650℃时，氧化速度随温度增加呈线性增加。不同相氧化速度不同，氧化主要发生在基体上，且含 V的 MC型碳化物周围氧化较快；而共晶区 M7C3型碳化物氧化最缓慢。

In-situo bservation of the surface oxidation behaviours of a highspeed steel roll

The oxidation behavior of a high-V high speed steel was observed in-situ by VL2000DX-SVF18SP ultra-high temperature laser confocal microscopy，and compared with the result of oxidation weight gain which was measured by a NETZSCHSTA449C differential scanning calorimeter/thermal gravimetric analyzer（DSC/TGA）during continuous heating process.The results showed that the microstructure of the high-V high speed steel consisted of spherical MC carbide particles distributed on martensite matrix and eutectic carbides of M7C3and M6C. In the process of continuous heating， when the heating temperature was lower than 480 ℃，the high speed steel almost did not oxidize with the increase of temperature，but when the heating temperature was higher than 480 ℃， the oxidation rate increased significantly with the increase of the increase of the heating temperature. When the heating temperature was over 650 ℃， the oxidation rate increased linearly with the increase of the heating temperature.The oxidation rate of different phases is different.The fast oxidation occurs around V-carbides，and the slower oxidation occurs in eutectic region.