| Abstract: | AbstractNew mathematical expressions for the prediction of hardness, yield strength and Charpy-V notch toughness of quenched and tempered steel were established. Quenched and tempered steel’s hardness is predicted based on as quenched hardness of steel. In the relation to hardness between quenched and tempered steel and as quenched steel, the hardenability of steel is taken in account. The mathematical model of hardness of steel is similar to the relationship established by Just. Yield strength and Charpy-V notch toughness of steel are predicted using the hardness of the quenched and tempered steel. Charpy-V notch toughness of cast steel is predicted using the Charpy-V notch toughness of steel with a same chemical composition. The mathematical expressions established were applied in computer simulation of mechanical properties of shafts made of quenched and tempered steel which the very well known relationship between hardness of as quenched steel and characteristic cooling time from 800 to 500°C (t8/5) during the quenching is used. |
