Engineering The Subsurface of Borided Aisi H13 Steel

Abstract

Boriding has been employed with some success to increase the service life of commercial forging dies fabricated from the hot work steel AISI H13. This steel is poorly suited to the treatment, however, since an undesirable intermediate layer is formed between the hard boride coating and the core. In practice, a boride coating thickness well below that required for the application has been imposed by the need to minimise the thickness of this layer. An experimental study was undertaken with the aim of improving the effectiveness of a boriding treatment by engineering the subsurface of AISI H 13 steel. It was established that a carburising pretreatment markedly improved the microstructural features of the steel subsurface. The formation of the undesirable layer was completely inhibited within the range of boride thicknesses employed in commercial practice and severely limited at the higher thicknesses better suited to forging applications.