Structure and properties of a low-carbon steel surface modified by electric arc surfacing

Resumo

The structural-phase state and the distribution of microhardness over the cross section of single and double coatings deposited onto martensitic Hardox 450 low-carbon steel by alloyed flux-cored wire, are studied using modern physical materials science. It is demonstrated that the microhardness of a double deposited layer 10 mm in thickness exceeds the microhardness of the base metal by more than three times. It is found that the improved mechanical properties of the deposited layer are due to the formation of a submicro- and nanodisperse martensitic structure containing iron borides forming a plate-type eutectic. Plates of iron boride Fe₂B are formed in the eutectic in a single deposited layer, and in a double-deposited layer, plates of FeB are formed. The existence of bend extinction contours, indicating the formation of internal stress fields at the interface between the phases of iron borides and α-iron borides, is revealed.