Characterization and Boron Diffusion Kinetics on the Surface-Hardened Layers of Royalloy Steel

The Royalloy steel was boronized at 1173, 1223, 1248, 1273 or 1323 K for 1, 3, 5, 7 10 h using a Durborid powder mixture. samples were analyzed by scanning electron microscopy, X-ray diffraction and Vickers microhardness testing. kinetic activity of layers growth obeys the parabolic law, maximum thickness 182 ± µm. FeB makes up to 40% total layer thickness. obtained have two phases, which composed Fe2B except sample 1173 1 had an only. phase range 1370–1703 HV0.1, that within 1727–2231 HV0.1. During boronizing process, chromium created extra particles with highest amount in transient region. silicon observed boride layer/substrate interface. manganese slightly lower compared substrate. Finally, integral diffusion model applied determine boron activation energies layers, this followed comparison literature data.