Abstract
Quenching of steel components results in complex and hard-to-predict dimensional and shape changes (distortion). Even the components manufactured from different parts of the same semifinished product may show significantly different distortion behaviours during quenching. The reason is thought to be non-uniform distribution of distortion potential carriers in the final component (i.e. alloying elements, segregations, residual stresses and phases) which are accumulated throughout the whole manufacturing chain. This study focuses on the effects of alloying element distribution and segregation on quench distortion. For this aim, long cylinders of various diameters were machined from 45 mm diameter SAE 52100 steel bars, and marked to define their exact positions in the initial bar. Then the cylinders were austenitised in a vertical furnace under nitrogen atmosphere and quenched in a gas nozzle field. The coordinate measurement results show that dimensional changes deviate significantly with machining position; however, the bending magnitudes and directions do not exhibit a distinct correlation with machining position and the cylinder diameter.
This research was carried out within the scope of the Collaborative Research Center SFB570 ‘Distortion Engineering’ at the University of Bremen (Bremen, Germany). The authors would like to acknowledge the Deutsche Forschungsgemeinschaft (DFG) for the financial support. This paper is based on a presentation at the 18th IFHTSE Congress held on 26–30 July, 2010 in Rio de Janeiro, Brazil.