Patent ID: 6843867

Claim:
A method of austempering of steel parts, comprising the steps of: (a) austenitizing the steel parts; (b) quenching the steel parts to a start temperature which is higher than a martensite start temperature of the steel parts; (c) at least approximately isothermally holding the steel parts at the start temperature for a first time period; and (d) at least approximately isothermally holding the steel parts at a finish temperature which is higher than the start temperature for a second time period; wherein a core hardness of the austempered steel parts after the steps (a), (b), (c) and (d) are performed is reduced during performance of the steps (a), (b), (c) and (d) compared to the core hardness of the steel parts before the steps (a), (b), (c) and (d) are performed.