炭素鋼および低合金鋼中のマンガンの状態分析

Abstract

This work, a part of a general investigation on the state analysis of steel, was carried out to develop a systematic method for isolation and determination of manganese compounds in carbon steel and low alloy steel.1. Isolation of manganese compound from steel.(a) The steel sample covered with close-texture filter paper as a diaphragm is, as an anode, dissolved into 130 ml of 1% NaC1- 5% EDTA electrolyte (pH 6-7) at a current density of 50 mA/cm2 for 2 hr. Remove the anode and the residue is collected into a beaker using methanol.(b) To the residue add 50 ml of 2% EDTA solution (pH5-6) and shake for 30 min. Filter and wash with water. To the filterate add 10 ml of HNO3 and 10 ml of HCIO4, and evaporate to dense white fumes. Determine Mn as carbide in accordance with section 2.(c) Transfer a part of the electrolyte to a beaker. Add 15 ml of HNO3 and 10 ml of HCIO4 and evaporate to dense white fumes. Determine Mn as solid solution in accordance with section 2.(d) Transfer the paper and residue (paragraph (b)) to a beaker, add 30 ml of 2% EDTA solution and 20 ml of 5% H202 and shake for 60 min. Filter and wash with water. To the filterate add 10 ml of HNO3 and 10 ml of HCIO4 and evaporate to dense white fumes. Determine Mn as sulfide in accordance with section 2.(e) Transfer the paper and residue (paragraph (d)) to a beaker, add 30 ml of HNO3 and 10 ml of HC104 and evaporate to dense white fumes. Determine Mn as oxide in accordance with section 2.2. Determination of manganeseAdd 50 ml of water, 3 ml of H2SO4, 4 ml of H3P04 and 20 ml of 5% NalO4, solution to each beakers (section 1 (b), (c), (d) and (e)), and boil for 5 min. Cool, dilute to 100 ml. Measure the absorbance of solution against water at 530 mμ.