A Study on the Effects of Induction Hardening on Torsional Fatigue Strength

Abstract

Previously the authors pointed out that the endurance limit under rotating bending of a solid circular specimen of plain carbon steel, especially the one with circular groove was enormously improved by "Induction Hardening". Since then "Induction Hardening" has been applied to miscellaneous machine parts, particularly force-fitted or notched parts under such condition. This method was also expected to be useful for the helical springs made of medium-carbon steel. This time they investigated torsional fatigue limit of induction-hardened medium-carbon steel (C=0.41% steel) by a 200kg-m Schenck type fatigue testing machine, with the intention of applying it to helical springs. From the results, it could be confirmed that there was a possibility of manufacturing induction-hardened helical springs.