Resistance against Abrasive Wear and Corrosion of Laser Powder Bed Alloyed High Chromium Tool Steels

• Published in: Steel research international 2023-04, Vol.94 (4), p.n/a
• Main Authors: Köhler, Marie Luise, Radtke, Felix, Norda, Michael, Herzog, Simone, Kaletsch, Anke, Petzoldt, Frank, Broeckmann, Christoph
• Format: Article
• Language: English
• Subjects: Abrasive wear; abrasive wears; alloy designs; Alloy development; Alloy powders; Alloying; Atomizing; Carbon tool steels; Chromium carbide; Cold work tool steels; Corrosion resistance; corrosion resistances; Corrosive wear; Cutting wear; Electron imaging; Hardenability; High alloy steels; Inclusions; Industrial applications; laser-based powder bed fusion; Mechanical properties; Microstructure; Powder beds; powder blends; Rapid solidification; Residual stress; Wear resistance
• ISSN: 1611-3683; 1869-344X
• DOI: 10.1002/srin.202200455

Additive manufacturing by laser‐based powder bed fusion of metals (PBF‐LB/M) enables the production of complex shaped components. High‐carbon tool steels tend to cracking during PBF‐LB/M due to internal stresses caused by the rapid solidification. Expensive atomization and long lead times for powder generate high costs in this processing route. In situ alloying during PBF‐LB/M of powder blends from conventionally available powders enables a more flexible approach of alloy design. For industrial use, the mechanical properties of in situ alloyed parts must be comparable to those of conventionally manufactured parts. In some cutting and forming applications, high wear resistance and corrosion resistance are required simultaneously. High alloyed cold work tool steels with sufficient chromium solved in the metal matrix fulfill these demands. Herein, AISI H13 is modified by Cr3C2 and elemental Cr to suit these requirements. Two novel alloys are modeled thermodynamically and processed by PBF‐LB/M. In‐depth microstructural investigations by backscatter electron imaging and diffraction in combination with abrasive wear tests and potentiodynamic polarization curves allow microstructure property correlations for different heat‐treated conditions. Partial crack‐free processing, hardenability, formation of Cr‐rich carbides, and residual Cr‐rich inclusions are observed and their influence on the wear and corrosion resistance is discussed. Two powder blends of AISI H13 with Cr and Cr3C2 are processed by laser‐based powder bed fusion to create new corrosion‐ and wear‐resistant alloys. The alloys are less wear resistant against coarse abrasive media than a conventionally processed reference AISI 440C but show better intergranular and pitting corrosion resistance.