A Comparison between the Effect of Heat Treatment and Plasma on the Wear Activities and Corrosion Resistance of Ni-B Electroless Coating with AISI 4340 Steel

The study the hardness, wear corrosion resistance of as-coating, heat treatment and plasma-nitriding of Ni- B electroless coatings was deposit on 4340 steel. After the procees of coating, samples were plasma-nitriding in percentage hydrogen/nitrogen ratio (50%), in the temperature 400°C, at 4 hours were compared with heat treatment. characterization by of FESEM, XRD, microhardness, Corrosion Resistance and surface roughness measurements. Microhardness was show highest hardness of 1050 HV was obtained for Ni-B plasma-nitriding formula whereas the greatest hardness of 800 HV was become for sample of Ni-B heat treated. Ni-B coating is used in the enhancement of properties of the corrosion of AISI 4340 steel is due to the thickness of electroless deposition, which is uniform, and the cold of Ni-B coating to act as an active barrier between corrosion media and metal, it should be noted that the value of Ecorr is less negative and the rate of corrosion and Icorr is lower on the plated sample than on the uncoated sample. The rate of the wear for samples is decrement by plasma-nitriding with deposition time at (4h) and the temperature 400°C. Rate of wear for the materials depends not just into condition of wear test, but also with several properties of material and features as topography, hardness and friction coefficient.