The carbonitriding of fasteners is of critical importance to their functionality and one of the most common case-hardening heat treatments. Studying how the process works in this application will shed a great deal of light on all carbonitriding processes.

There is a group of recurring questions asked of The Heat Treat Doctor, all of which are centered around: “How much surface oxidation is allowable on a steel part?”

The subject of carbide formation in steels has intrigued The Doctor ever since he first peered into a microscope and observed them. Carbides can be our friend or our enemy.

Most, if not all, heat treaters – whether they like to admit it or not – enjoy the challenges that present themselves when confronted by a new material or the need to develop a new process recipe to achieve specified properties or results.