Microstructural Behaviour of Tempering Steels during Precision Forging and Quenching from Hot-forming Temperatures  Full text 

F. Nürnberger, O. Grydin, Z. Yu, M. Schaper

Faculty of Mechanical Engineering, Institute of Materials Science
Leibniz University Hanover, An der Universität 2, 30823 Garbsen, Germany

UDC 621.771:669.017.3

Metall. Min. Ind.,  2011, Vol. 3, No. 7, pp. 79-86

Abstract

To design a precision forging or twin-roll casting process combined with heat treating from the hot-forming temperature, flow curves for a selection of hardening and tempering steels were recorded using a deformation dilatometer. In addition to this, continuous cooling transformation diagrams were generated for the 42CrMo4 hardening and tempering steel. These diagrams take into account the influence of deformation on the transformation behaviour during quenching from a temperature of 850 °C. The results of the investigations show an increase in the flow stresses with decreasing temperatures and the deformation's minor influence on the resulting material's hardness and microstructural constituents

Keywords: TEMPERING STEEL, QUENCHING FROM HOT-FORMING TEMPERATURE, FLOW CURVES, CCT