We are reviewing the developments that have taken place within the heat-treatment processing industry on an international basis.

Surface Treatment

Surface treatments were initially by the process of carburizing followed by austenitizing, quench and temper. It was very soon recognized that the carburizing process was somewhat limited. The first surface transformation deviation from carburizing was in 1903 with Adolph Machlet’s patent application for the process of gaseous nitriding. In the late 1920s, two German metallurgists named Berghaus and Wienheldt started the research into the surface treatment of steel by the utilization of plasma generation.

It became evident that the use of plasma technology could enhance the surface treatment of a steel surface using a steel with a preheat-treated core procedure followed by nitriding, which could then be further treated to produce a hard, abrasion-resistant surface.

The basic nitriding procedure (be it gaseous, salt or plasma-enhanced) also offered improved corrosion resistance and fatigue resistance. From the simple thermochemical procedure of nitriding, it was soon discovered that the immediate surface of nitriding can be modified.