Cr₃C₂-20%NiCr溶射皮膜の強度に及ぼす熱処理の影響

抄録

The effect of heat treatment on the strength of Cr₃C₂-20%NiCr coatings sprayed on 13%Cr-5% Ni steel by high-velocity oxygen fuel (HVOF) spraying has been studied. Specimens were heated to 823 K and held for 1, 5, and 15 h. The strength and hardness of Cr₃C₂ 20%NiCr-sprayed coatings were measured by a tensile test and a micro-Vickers hardness test. The results obtained were as follows. (1) Heat treatment increased the strength and hardness of the Cr₃C₂-20%NiCr-sprayed coatings. (2) The treatment decreased the maximum peeling area on the 13%Cr-5%Ni steel base under the cracks produced in tensile tests. (3) The mechanism of the strengthening of Cr₃C₂-20% NiCr sprayed coatings by heat treatment is considered to be as follows. The heat treatment divides the blowhole cracks in the coatings into smaller subvoids and decreases the extension paths of steel base, thus strengthening the adhesion force and hardening the sprayed coating.