Inductive Heating and Quenching of Planetary Shafts for Diesel Engine Starters

Abstract

High mechanical and temperature cyclic loading of the final products for automotive, transport, construction and agriculture mechanization industry, demands sufficient mechanical properties of all of their components during its exploitation. Majority of the components is made of steel, by different cold forming processes. Their main demanded characteristics are surface wear resistance and fatigue strength under pulsating stress in combination with cyclic temperature loading, which could be achieved only by appropriate heat treatment. The efficiency of the combined inductive heating and water quenching heat treatment and quality of the planetary shafts were analyzed, with the use of thermographic analysis, hardness measurements, and metallographic examination. Combination of inductive heating and water quenching is the most effective heat treatment process of carbon steel planetary shafts for the diesel engine starters. Long life span of carbon steel planetary shafts it’s essential for their economical production. The replacement of starter is expensive from both: money and working time point of view. Surface temperature measurements during the inductive heating process were performed in the industrial environment. The intensity and homogeneity of the planetary shaft surface temperature field was measured by thermographic camera. On the base of theoretical knowledge and measurements, a mathematical model for temperature conditions determination in the shaft during the entire process of heating and quenching was carried out, and used for analyses and optimization of planetary shafts induction hardening process.