Tufftriding Q,QP & QPQ
Tufftride is a liquid ferritic nitrocarburising process which diffuses nitrogen and carbon into the surface of ferrus metals in special salt baths, after which they are oxidative quenched to give a black finish.
Two distinct microstructual zones are procuced. On the surface, a thin (10-15 microns), hard, ductile layer of epsilon-iron-nitride is formed. Beneath this compound zone a much deeper nitrogen-rich diffusion zone is to be found, giving a combined depth of .35-.70mm depending on the material being treated and the processing time selected.
QPQ processing adds polishing and re-oxidation operations, which further enhance material performance. It also produces a lustrous black finish, ideal for customer product applications where cosmetic appeal is an important consideration.