Structuring carbon alloys due to carbon mass transfer

Abstract

The wear of parts of the threshing apparatus of a combine harvester inevitably leads to the deterioration of the threshing of the grain mass, which in turn leads to the loss of grain. One of these parts involved in the direct threshing process is the whipping threshing drum made of high carbon steel. Used steels of increased strength for the manufacture of parts, components and structures of agricultural machines requiring restoration using surfacing with wear-resistant coatings are hampered due to the tendency of such steels to form hot and cold cracks in the near-weld zone. The main reason for the formation of cold cracks during the welding of steel parts is considered to be the unfavorable development of physicochemical processes in the heat-affected zone of welding. The highest probability of the formation of deformations and residual stresses in austenitized regions of the heat-affected zone is characteristic of steels with a high carbon equivalent. As a result of the research conducted, the possibility of reducing the carbon content in the welded edges and weld surfaces of carbon steel products by creating a temperature gradient in them directed from the surface to the core was substantiated and experimentally confirmed. The local decarburization that occurs during this process is reversible, and after performing the surfacing, it is easily eliminated by normalization.