Analysis of semi-solid extrusion products made of steel alloy X210CRW12

Abstract

The bar extrusion process is characterised by extruding a billet through a forming die with a punch. Compared to conventional bar extrusion other tool concepts are required for semi-solid extrusion processes because forming has to take place in the semi-solid state, followed by a solidification step [1]. Under variations of the main process parameters like press velocity, extrusion channel length and die as well as the press channel geometry semi-solid extrusions are performed. The bars are characterised by a limited length due to insufficient solidification in the extrusion channel. Analyses concerning chemical composition, pore formation, microstructure and mechanical properties discover properties independent of the chosen process parameters. The chemical composition is constant over the bar length. It differs between globulites and eutectic. In the homogeneous microstructure few pores can be found. The determination of the mechanical properties shows a wide range of values because of the pores included in the bars.