Evaluation of mechanical properties and corrosion resistance of various coating systems used on tool steel in the mould industry

Abstract This paper presents a comprehensive assessment of the surface and functional properties of selected tool steels (1.2343, 1.2083, 1.2378 and Toolox 44) coated with BALINIT LUMENA, BALINIT CROVEGA, BALINIT CROMA PLUS and BALITHERM PRIMEFORM protective coatings. The research aimed to determine their suitability for industrial applications, in particular in polymer injection moulds exposed to high temperatures, pressure and corrosive environments. The evaluation included microhardness analysis (HV1), surface roughness measurements, morphological observations using scanning electron microscopy (SEM) and Keyence optical microscopy, as well as tribological tests. In addition, techniques such as ellipsometry and reflectance angle analysis were used to characterize the surface properties of the coatings in detail. To determine chemical stability, corrosion resistance tests were performed under hydrothermal incubation conditions (80°C, distilled water, 14 days) and the chemical composition of the substrate was analysed using X-ray fluorescence (XRF). Comprehensive testing has shown that the correct choice of protective coating is crucial for the durability and reliability of moulds in injection moulding processes. In particular, the BALINIT® CROMA PLUS coating, thanks to the synergy of high microhardness, corrosion resistance and stable optical and tribological properties, is the most promising solution for industrial injection moulding applications.