Abstract
A simple and economical process for boriding metal surfaces was found. The process was only to immerse the metal in a hot salt bath containing borax and carborundum, where no special atmosphere was needed.
Optimum conditions found for boriding of mild steel were to dip the steel in a bath containing 60-50wt% of borax and 40-50wt% of carborundum at 1, 000°C for 6hrs. The boride layer produced by this process was composed of Fe2B, which was 170μ in thickness, having about 1, 200 of Vickers hardness.
The mild steel lying beneath the boride layer was also observed hardened. The results of chemical analysis and electron probe microanalysis showed that the hardening of the interior mild steel was attributed to the boron and carbon penetrating through the boride layer.
