The Effects of Overlapping in Electrolytic Plasma Hardening on Wear Behavior of Carbon Steel

Electrolytic plasma hardening (EPH) provides more rapid hardening than conventional hardening processes, including minimum distortion in the parts. The influence of overlapping ratio (Overlapped 10%, 50%) in EPH was compared on hardness, microstructure geometry of the hardened zone and overlapping zone. Reciprocating sliding wear tests were carried out on modified and overlapped AISI 1040 steel. The surface morphology and wear surface were analyzed by scanning electron microscope. The microhardness of modified layer was investigated. The results show that the hardness of AISI 1040 steel is approximately 250 HV0.2, and the hardness after EPH surface heat treatment is around max. 1000 –1050 HV0.2. The single-track EPH modified samples show the best wear resistance. The overlapped zone is the tempered zone and consist of sorbite and tempered martensite. The hardness of sorbite is significantly lower than that of martensite. Therefore, the AISI 1040–10% and AISI1040-50% samples’ wear resistance decrease with overlapping