| 摘要 |
<p>1413857 Chromium carbide layers; forming Cr carbide electrolytically TOYOTA CHUO KENKYUSHO KK 6 Nov 1973 [16 Nov 1972 12 April 1973] 51368/73 Headings C7B and C7F Boric oxide and/or a borate is heated to form a molten bath, a metal block containing Cr is dipped therein and made anodic so that it dissolves, and an iron, Fe alloy, or cemented carbide article containing at least 0.06%C is immersed in the bath, to receive a chromium carbide coating. The bath may contain B 2 O 3 , Na 2 B 4 O 7 , or K 2 B 4 O 7 , and its viscosity may be reduced by addition of NaCl, KCl, NaF, P oxides, hydroxides, sulphates, carbonates, or nitrates; the block is pure Cr or alloy such as ferro-chromium, and using 0.1-10A/cm<SP>2</SP> for 30 min-5 hr this dissolves to give about 1%Cr in the bath; immersion of an article at 800-1100‹C for 1-30 hr under air or inert gas after or during dissolution of Cr gives a Cr carbide layer. The cemented carbide substrate is WC/Co optionally containing TiC, NbC, or TaC.</p> |
