High Carb— Erhöhung der Anlassbeständigkeit beim Einsatzhärten

Case hardening is the most important heat treatment process for highly stressed components in engines, gear boxes, machines, etc. Nevertheless some disadvantages prevail, e.g. distortion due to oil quenching, internal oxidation and limited temper resistance up to 200°C in combination with standard case hardening steel grades such as 16MnCr5. In the past efforts were made to remove at least some of the disadvantages mentioned above. The only way to achieve tempering restistance beyond 300°C is swapping to significantly higher alloyed and therefore more expensive case hardening steels (e.g. 15NiMoCr10). Rübig was confronted with numerous customer inquiries regarding possiblities to increase temper restistance by means of case hardening in combination with standard case hardening steel grades like 16MnCr5. As a resul of HighCarb the case hardening steel grade 16MnCr5 yields a surface hardness after tempering at 300°C of approx. 60.5 HRC. An additional benefit is, that HighCarb-treated parts show a very fine grain, no discernible retained austenite (by means of light microscopy) and very little internal oxidation.