Research of the protective ability of coatings on steel powder against atmospheric corrosion

Abstract

Storing the main material for additive technologies, i. e. metal powder compositions made from steels and alloys with low corrosion resistance, is a challenge. We studied the protective ability of coatings applied by chemical heat treatment (CHT) to the surface of a steel powder, which has low resistance against atmospheric corrosion. Long-term two-year tests of powder samples with various coating compositions were carried out at natural atmospheric humidity and ambient temperature in the Northwestern Federal District of the Russian Federation. The chemical composition of the samples was evaluated before and after the test. The chemical composition and morphology of the particles were determined by electron microprobe (EMP) using a scanning electron microscope (SEM). It is shown that coatings applied by the CHT method do not create continuous protection and accelerate corrosion processes in comparison with the heat-treated powder of the initial steel.

Keywords

• additive technologies
• laser powder bed fusion
• direct metal deposition
• metal powder compositions
• corrosion protection
• chemical heat treatment