The effects of additive elements on the microstructure characteristics and mechanical properties of Cr-Fe-C hard-facing alloys

The present investigation discusses the effects of V, Mo, and Ni addition on the morphologies and mechanical properties of primary carbides and eutectic colonies in Cr-Fe-C hard-facing alloys with hypereutectic compositions. Findings show that V, Mo, and Ni addition obviously affects the hardness and indentation fracture (KC) of primary carbides and eutectic colonies. V addition to alloy A can slightly increase the hardness of primary carbides varying from 1503 ± 17 to 1551 ± 13 HV but slightly decreases the KC value of primary carbides ranging from 3.80 ± 0.15 to 3.64 ± 0.14 MPa m1/2. Mo addition to alloy B can increase the KC value of primary carbides ranging from 2.35 ± 0.11 to 2.67 ± 0.08 MPa m1/2. Ni addition to alloy B can decrease the hardness of eutectic colonies varying from 769 ± 9 to 608 ± 13 HV. Maximum hardness was obtained in the coated surface of alloy B due to the formation of large amounts of primary M7C3 carbides.