A mechanical aspect of borides formed on the AISI 440C stainless-steel

In the present study, some properties of borides formed on AISI 440C stainless-steel have been investigated. Boronizing was carried out in a solid medium consisting of EKabor(R) powder at a temperature of 950degreesC for 2-8 h. The presence of borides e.g. FeB, Fe2B, CrB, Cr2B, Mn2B and MnB were revealed by means of X-ray diffractometry, scanning electron microscopy, and optical microscopy. The hardness of borides which was over 1500 VHN and boride layer thickness were measured and it was observed that, the thicknesses of the boride layers were strongly dependent on the process time, and chemical composition of the substrate materials. It was also found that the longer boronizing time results in an increase in thickness layer; the thickness of boride layers ranged from 10 to 50 mum. Optical microscopy examinations of the borides formed on the surface of AISI 440C stainless-steel substrate revealed a smooth and compact morphology. To determine distribution of alloying elements from surface to the interior energy dispersive Xray spectroscopy was used. (C) 2004 Elsevier Ltd. All rights reserved.