The fabrication of high volume fraction(HVF) M7C3(M=Cr, Fe) reinforced Fe-based composite coating on ASTM A36 steel plate using plasma transferred arc(PTA) welding was studied. The results showed that the volume fraction of carbide M7C3 was more than sixty percent, and the relative wear resistance of the coating tested on a block-on-ring dry sliding tester at constant load(100 N) and variable loads(from 100 to 300 N) respectively was about 9 and 14 times higher than that of non-reinforced α-Fe coating. In addition, under constant load condition the friction coefficients(FCs) of two coatings increased first and then decreased with increasing sliding distance. However, under variable loads condition the FCs of non-reinforced α-Fe based coating increased gradually, while that of HVF M7C3 reinforced coating decreased as the load exceeded 220 N. The worn surface of non-reinforced α-Fe based coating was easily deformed and grooved, while that of the HVF M7C3 reinforced coating was difficult to be deformed and grooved.
