The deformed layers generated in face milling works were comparatively investigated to type 3l6L and nitrogen(N)-added type 3l6LN stainless steels. In order to characterize mechanical properties between type 3l6L and type 3l6LN, high-temperature tensile tests were conducted with different temperatures: R.T. to 700°C. The cutting forces of three components, Fx, Fy and Fz were measured using a tool dynamometer through the face milling cutting tests. The deformed layers were measured by micro-hardness tests along deformed layers. The results of mechanical properties showed that type 3l6LN was superior to type 3l6L. The deformed layers of two steels were generated in the 150㎛-300㎛ ranges, and type 316L was higher than type 316LN. The reason for this is due to the high strength properties by nitrogen effect. It was found that deformed structures were well observed for type 3l6L, but were minutely observed for type 3l6LN in this cutting conditions.
