Gas-powder laser cladding of coatings on steel parts in transport construction

Abstract

Wear-resistant coatings solves the problem of recovering highly worn parts in transport construction. For this, various technological processes for applying metal coatings are used. One of these is laser cladding. The use of a laser beam in cladding ensures low dissolution of the base in the pad, good adhesion to the base metal, and high quality of the pad. The features of the processes of obtaining surface coatings largely depend on the type and shape of the filler material and on the methods of introducing it into the laser treatment zone. As a result of the study of the cladding of the powders, the processing modes were determined in a wide range and in the “purest” form of coating properties, i.e. without the influence of the base metal. Separate weld beads were deposited on the samples. The beam was scanned along a circular path, which left a spiral trace on the sample surface, taking into account the translational motion. Assessment of the quality of cladding and microhardness was carried out on the cross section of a metallographic section. Pores, cracks, lack of fusion, non-metallic inclusions were noted. The highest quality coatings were obtained using PG-US25 powder. The formation of the coating is of higher quality. The absence of pores and cracks in the pad is ensured when the deposited powder is mixed with the base metal (there is a kind of “dilution” of the composition with respect to carbon).