Diffusion and Phase Transformation at the Interface between an Austenitic Substrate and a Thermally Sprayed Coating of Ledeburitic Cold-Work Tool Steel

• Published in: Steel research international 2011-06, Vol.82 (6), p.671-682
• Main Authors: Röttger, Arne, Weber, Sebastian, Theisen, Werner, Rajasekeran, Balasundaram, Vaßen, Robert
• Format: Article
• Language: English
• Subjects: Austenitic stainless steels; bond strength; Coating; cold-work tool steel; Diffusion; Diffusion coating; Heat treatment; HVOF; Near net shaping; Steels; thermal spraying; Tool steels
• ISSN: 1611-3683; 1869-344X; 1869-344X
• DOI: 10.1002/srin.201000199

An overlay coating against wear or corrosion on components is required for various technical applications. Thermal spraying is a well‐established and near‐net‐shape deposition method. In this work, high‐velocity oxy‐fuel spraying of two different ledeburitic cold‐work tool steels was employed to produce wear‐resistant Fe‐base coatings on a stainless steel substrate. This work focuses on the investigation of diffusion processes across the coating/substrate interface. Specimens were heat‐treated for different dwell times and then analyzed by means of EBSD, XRD, OM, as well as SEM. Results of phase formation and diffusion profiles were compared with equilibrium and diffusion calculations obtained with ThermoCALC® and DICTRA®. The influence of diffusion processes across the coating/substrate interface on the mechanical properties, such as adhesive bond strength and hardness, was investigated by shear tests and microhardness profiles.