Structural-phase states and properties of coatings welded onto steel surfaces using powder wires

Structural-phase states and mechanical properties of coatings welded onto Hardox 400 steel using En-DOtecDO*30, EnDOtecDOtec*33, and SK A 70-G weld wires are investigated via X-ray structural analysis, optical and scanning electron microscopy, and measuring microhardness, wear resistance, and friction coefficients. It is shown that the coatings had microhardnesses and wear resistances were higher than those of their substrate by factors of 2–3 and 2, respectively, while the friction coefficients of coatings were lower than those of the substrates by a factor of 1.2. Hardening was due to the formation of disperse structures containing up to 40 vol % of Fe3C, Fe23(C, B)6, NbC, Fe3B, and Fe3Si0.97 particles.