Fundamental Study on Isolation and Determination of Carbides in Steel

Some mineral acid separation and potentiostatic electrolysis method for isolation and determination of various carbides in steels have been fundamentally investigated.The results obtained are summerized as given below.1. Globular and coarse Fe3C and other various carbides such as TiC, ZrC, VC, NbC, (Cr, Fe) 7C3, (Cr, Fe) 23C6, Mo2C and (Fe, W) 6C were extracted quantitatively by means of potentiostatic electrolysis method with 15% sodium citrate-1.2% KBr-30% citric acid or acethyl aceton-1% tetramethyl ammonium chlolide-methanol electrolyte.2. The reproducible separation of TiC, VC and NbC with HCl (1+1) and (Cr, Fe) 7C3, (Cr, Fe) 23C6and Mo2Cwith H3PO4 (2+1) could be successfully accomplished if these carbides were relatively coarse.3.TiC, ZrC and VC being considered insoluble in mineral acids were found to be attacked gradually by diluted HCl, H2SO4and H3PO3and were mare easily dissolved as the particles cf the carbide were fine.