Kinetic and mechanical properties of boronized AISI 1020 steel with Baybora-2 powder

Abstract

In this study, package boronizing process was applied to AISI 1020 steel by using Baybora-2 boronizing agent and the kinetics of boronizing process was investigated. The pack boronizing process was performed at 1223 and 1323 K temperatures for 2, 4 and 6 h. The properties of the boride layer formed on the surface as a result of the boronizing process were determined using optical microscopy and SEM analysis. XRD analysis was performed to determine the phases formed in the boride layer. As a result of the analysis, it was determined that the boride layer consisted of FeB and Fe2B phases. It was determined that the thickness of the boride layer increased with the increase of boronizing time and temperature. While the boride layer thickness for the temperature of 1223 K was between 115 and 196.3 μm, the boride layer thickness for the temperature of 1323 K was found to be between 157.2 and 304.7 μm. In this study, a boriding powder, patented and under development, was used and a surface layer with a hardness of 2224 HV was obtained on the surface of AISI 1020 steel. This hardness value is approximately 5 times the hardness values of steels hardened by traditional surface hardening methods such as cementation and nitriding. Also, considering the boride layer thicknesses, the activation energy was calculated as 162.26 kJ/mol using the classical kinetic method.