NIPRE®

Fig.1: Huge moulds for die-casting after Nipre treatment. Introduction: In the heat treatment industry there are currently new proposals to improve the surface of steel objects against damages caused by wear, erosion, corrosion and thermal fatigue. After a proper hardening and tempering process, the modification of surface properties is made up of interstitial diffusion of the three light alloys: N, C, and O inside the steel structure. For some applications a light coating in P.V.D. o P.A.C.V.D. (TiAlN, CrN, ZrN) has been discovered to be extremely useful on a diffusive process. Although for the industry sector there are different solutions ranging from gas to salt bath nitriding, from ion nitro-carburizing to the different kind of coatings, the need of an adequate protection to avoid excessive wear, consumption or damages is still required. An example may be offered by the industry of die-casting for light alloys, where the improvement rate is very high (Al, Pb, Copper, Zama alloy). In particular we would like to show the solution for a particular kind of mould with their relative cores and males made up in steel for hot-working AISI HI 1 (5% Cr).