Study on the Electrolytic Isolation of Carbide from Steel

Study on nonmetallic compounds-I

Abstract

The present paper deals with the technique for the electrol ytic isolation of carbide from steel, without decomposition and contamination, by using the Koch -Sundermann method and others.
The results obtained are as follows.
(1) In order to dissolve all the matrix metal, the surface electric potential of steel mussetbtl oe wer than the hydrogen potential.
(2) In the case of dissolving in a partly passive state of steel surface, it is not desired to isolate the carbide at a too low current density. On the other hand if steel is dissolved in an active state, it need to isolate at a current density as low as possible.
(3) The residues isolated electrolytically must be dried and weighed under the cona dithioignhvs aocf uum and a high temperature.
(4) Copper or its compounds are contaminated in the residues isolated electrolytically from the low-alloy steel containing copper. (Cu content is 022%). When this copper included is separated from the residues by using KCN solution, part of carbide also tends to be decomposed.
It is found that using the ammonium solution, this copper can be separated from the residue isolated eleotrolytically in 5% Na-citrate+1.2% KBr solution.