Gearbox Production Using Distortion Controlled Inductive Fixture Hardening*

Abstract Fixture-hardening, also known as quench-press hardening, is a widespread process mainly for the automotive industry. This paper introduces a new inductive hardening and tempering process that combines the well-known advantages of induction heating and hardening with the advantages of a fixture hardening process to obtain highly precise workpieces with enormously reduced or even without rework. The main component is a new hardening machine with implemented fixture hardening assembly and integrated induction coil, all in a protective gas atmosphere. Induction as electrical energy source can be used for heating up workpieces prior to fixture hardening and for tempering, which allows to simultaneously draw out the calibration mandrel without any abrasive wear on its surface. In certain applications, an expanding mandrel can be used in order to relieve the workpiece.