Investigation of the penetration of the counter-body in the nitride zone of steels and analysis of concomitant characteristics

Abstract

The present research summarises the influence of technological modes based on experimental studies of steels BH11 and BH21 (BS 4659) for hot work in ion nitriding. The peculiarity is that one or several precisely defined modes are not fixed, but a group of parameters from the action of the considered technology in a planned experiment is studied. As a result, the technological modes of ion-nitrided steels are determined, corresponding to the minimal and maximal penetration of the counter-body in the nitrided layer. The obtained results are based on additional research related to microhardness and relative wear resistance. In this way a finished idea of the tribological properties of ion nitrided steels with a specialised purpose is obtained. The tools by which the problem is solved are design of experiments (DOE), modelling and single-criteria optimisation of controlled quantities. The main contribution of the paper is a formalised determination of the influence of the technological parameters of ionic nitriding on the phase composition of the nitrided zone and respectively on the wear resistance of the surface layer.