REPARATORY HARD FACING OF THE ROTATIONAL DEVICE KNIVES FOR TERRAIN LEVELLING

Abstract

The aim of this work was to study the possibilities for expanding the working life of certain parts of the civil engineering mechansation. This is why the mechanism of the impact abrasive wear of parts that wear the most, was analysed first, especially knives of the rotational device for terrain levelling. Then the possibility for their reparation was considered. Dominant types of wears, regarding these parts occur because of abrasion, adhesion and impact, depending on structure and composition of the terrain. Damages on knives in conditions of intensive, abrasive wear, while being in contact with knives working surface with materials of mineral origin, are regarded as a separate subject. The cutting edges of knives were regenerated by hard facing, and then they were sharpened by grinding to the similar shape and size as the new knives. After that, onto the working machine rotors were mounted alternatively new and repaired knives and their wear was monitored under the same working conditions. It was established that the endurance of the hard faced knives is better than that of the non hard faced ones, which can be explained by the more favourable microstructure of the hard faced layer that better corresponds to the given working conditions.