Improving the Wear Resistance of Ledeburitic Tool Steels by a Combination of Semi-Solid and Cryogenic Processing

Abstract

Ledeburitic tool steel X210Cr12 was processed by passing through a semi-solid state with subsequent forming on a hydraulic press, thus achieving a fine-grained martensitic matrix, uniformly dispersed fine precipitates, and removal of sharp-edged primary chromium carbides. The hardness value was over 700 HV10. The decomposition of austenite and the promotion of further carbide precipitation were carried out by cryogenic treatment or a combination of cryogenic treatment and tempering. Transmission electron microscopy showed that tempering after cryogenic treatment also led to the precipitation of needle-like M3C carbide, unlike the previous regimes. Furthermore, after the combined treatment, the microstructures showed a significant wear resistance, which was detected both by a waterjet abrasive blast test and a laboratory pin on disk test. Both tests showed a significant increase in wear resistance compared to the initial condition and special high wear resistance steels, such as Hardox 450 and Hardox 600.

Keywords

• tool steel
• semi-solid treatment
• cryogenic treatment
• carbides
• heat treatment