受賞記念講演
耐食性超硬合金の腐食メカニズムの研究と開発・実用化
キーワード:
WC-Ni-Cr cemented carbides,
corrosion resistance,
immersion test,
polarization curve,
seawater
2020 年 67 巻 10 号 p. 553-562
詳細
2020 年 67 巻 10 号 p. 553-562
Cemented carbides have been expanded for cutting tools and wear-resistant parts. Recently, the application has been expanded to pump and chemical plants that require corrosion resistance, and WC-Ni-Cr cemented carbides have been developed. In this study, microstructures, some mechanical properties and electrochemical corrosive behavior of WC-(0-16)mass%Cr3C2-15 mass%Ni alloys were studied as a function of carbon and Cr3C2 contents of these alloys. At the stage of practical application, the effects of carbon and Cr3C2 contents on their corrosion resistance were investigated by both immersion test and electrochemical polarization test in 3%NaCl neutral and 3%NaCl + 0.1NH2SO4 acid solutions as simulated sea water to clarify the corrosion reaction. Further, Galvanic corrosion between cemented carbides and steel, and the NaCl concentration in brackish-water region were investigated for standardization of WC-Ni-Cr corrosion resistant carbides for using seawater pump industries.
