ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Rate of Growth of Boride Layers on Highly Alloyed Steels

P. Fellner and M. Chrenková

Department of Inorganic Technology, Faculty of Chemical Technology, Slovak Technical University, CS-812 37 Bratislava

Abstract: Experimental results of thermochemical boriding of low-alloyed steel (CSN 11302) and high-alloyed chromium and nickel steels are presented. A semiquantitative model describing the rate of growth of boride layers as a function of composition of borided steel, composition of boriding medium, time and temperature of boriding is proposed. Parameters of the model are calculated. The model enables one to estimate the experimental conditions for boriding of alloyed steels.The distribution of chromium and nickel in the boride coatings and in the matrix has been determined metallographically and by electron probe microanalysis. It was found that the formation of the boride layer is accompanied by a redistribution of the alloying elements: the highest concentration of chromium was determined in the Fe₂B underlayer whilst in the phase FeB it was lower than in the matrix. An opposite behaviour was observed for nickel which concentrated preferentially in the outer FeB phase, this resulting in a Ni depletion in the Fe₂B underlayer.

Full paper in Portable Document Format: 464a226.pdf

Chemical Papers 46 (4) 226–231 (1992)