Abstract
In the present study, X-ray and chemical analyses were carried out on carbides isolated electrolytically from several high-V high speed steels, and the effect of carbon, tungsten and vanadium contents on the constitution of carbides in these steels were discussed. Carbides in high-V high speed steel are MC, M6C and M23C6, and the amount of these individual carbides varies depending on the steel composition.
The carbon-vanadium ratio is the most considerable factor. If this ratio is too low, the steel contains no M23C6, and is therefore incapable of being supplied with sufficient carbon into austenite for the formation of high hardness martensite on quenching. On the contrary, if this ratio is too high, the steel contains excessive amounts of M23C6, and the large amounts of austenite will be retained by quenching from the usual hardening temperature.
The desirable relation between carbon, tungsten and vanadium contents in high-V high speed steel was deduced approximately as follows