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The article deals with the process of surface remelting of steel 41CrAlMo7 by electric arc (TIG) in the presence of powders with a defined chemical composition. Commercially available powders Pulnierpulver based on calcium cyanamide (CaCN2) (source of nitrogen) and Durborit G based on boron carbide B4C (source of boron) were remelted. The effect of remelting on the change of microstructure in the remelted area was examined to achieve an increase in hardness and resistance to abrasive wear. The measurements of the hardness of HV 1 were carried out, as well as determination of resistance to abrasive wear on the abrasive cloth with Al2O3 particles. The microstructures of remelted layers were observed by LOM and details by SEM. By remelting the examined steel, a significant increase in hardness and resistance to abrasive wear was achieved to a depth of up to 1.5 mm from the surface. An almost four times increase in hardness and an almost two times increase in wear resistance was found when remelting the Pulnierpulver powder, or more than three times increase in hardness and more than 1.5 times increase in resistance to abrasive wear when remelting the Durborit G powder compared to steel without remelting. The presented procedure of TIG surface remelting of powders containing a certain element represents a cheap, accessible, and fast way of creating surface layers with increased hardness and wear resistance. The method is applicable for increasing the wear resistance of functional parts of machines for agriculture, earthmoving, etc. |
