Abstract
A study has been made of the sliding wear characteristics of boride layer formed on S45C steel by boriding. As compared with the unborided S45C steel, the wear resistance of boride layer was very large in sliding velocity region between 0.1 and 4.5 m/s. It was on a level with the wear resistance of SKS3 in sliding velocity region between 0.1 and 1.0 m/s, and it was larger than that of SKS3 in sliding velocity region between 2.0 and 4.5 m/s. In the wear characteristics of boride layer, the oxidative wear was preferentially observed in sliding velocity region between 0.1 and 1.0 m/s. The maximum wear rate was observed 1.4 or 2.0 m/s in sliding velocity and in this region the mechanical wear was observed. It was considered that the melting wear was caused in sliding velocity above 3.0 m/s. The metallic debris caused by sliding wear with borided steel-low carbon steel was produced even in the slow sliding velocity of 0.1 m/s, and it increased with the increase of sliding velocity. It was considered that the wear loss of boride layer was largely influenced by the metallic debris contents produced with sliding wear of borided steel-low carbon steel. The oxide that were produced in the oxidative wear region restrained the adhesion between frictional surfaces. It was confirmed by the X-ray diffraction that the oxide consisted mainly of Fe3O4 and α-Fe2O3.
