Mechanical properties of layers obtained by DC-pulsed plasma nitriding on a low-alloy steel (AISI 4140)

L. DUTREY, H.G. SVOBODA, P. CORENGIA, D. EGIDI, E. DE LAS HERAS, M. BRIZUELA, G.A. LOPEZ

Garmish

Conferencia; 11th International Conference on Plasma Surface Engineering; 2008

ESTF

An industrial DC-pulsed plasma nitriding (DCPPN) equipment was used to obtain samples of an AISI 4140 low-alloy steel with five different configurations: substrate, substrate + diffusion zone, diffusion zone, substrate + diffusion zone + compound layer, diffusion zone + compound layer. The microstructures of the samples were investigated by scanning electron microscopy and X-ray diffraction. Microhardness and tensile tests were also performed. The DCPPN produced an increase in the elastic modulus as well as in the yield strengths, together with a strong ductility decrease. The mechanical properties and fracture mechanisms taking place for the different materials were discussed and analyzed