LPC and LPN of tool steel fuel-injection nozzles

This article describes the newest achievements in the heat treatment of diesel-engine fuel-injection nozzles made of hot-working tool steel. Different methods of improving surface properties have been applied by means of vacuum carburizing and vacuum nitriding, which is especially suitable for elements characterized by difficult shape geometry such as blind holes. Variable process parameters have been considered in terms of sequence and temperature as well as their influence on surface microstructure, hardness and case-layer uniformity.