Valve push rod heat treatment - using carburisation, reheating, oil quenching and tempering of partially machined steel rod contg. carbide promoting alloy elements

摘要

The part of the valve push rod which is in contact with the cam requires a very hard surface to witstand the wear due to friction. This is achieved by using a steel containing elements such as chromium, molybdenum, vanadium tungsten and niobium, which promote carbide formation. The total of these elements amounts to a minimum of 1.25%. The partly machined components are carburised for 12 hours at 920 deg.C. and then cooled. This is followed by re-heating to 900 deg.C. and quenching in oil at 80 deg.C. The parts are then tempered for one our at 160 deg.C. This treatment produces a hardness after final grinding of 65 Rockwell.