Torsional Fatigue Behavior of Through Surface Hardening “TSH” Steel Compared to Carburized SAE 8620 Steel

Torsional Fatigue Behavior of Through Surface Hardening “TSH” Steel  Compared to Carburized SAE 8620 Steel

E. M. Govier and M.J. Glass: Eaton Vehicle Group, Materials & Power Transfer Systems Engineering CoE, Galesburg MI

A new technology has been introduced to the North American market as a potential replacement to conventional carburizing.  This new approach called Though Surface Hardening or “TSH” technology utilizes low hardenability steel and induction hardening to create a contoured hardened pattern, similar to a traditional gas carburizing process.   In this study, TSH processed and conventional gas carburized fatigue samples were subjected to reverse torsional loading, generating comparative S-N curves.  This paper outlines the torsional fatigue performance  and metallurgical characteristics for each process type.