黒鉛形状を異にする実用鋳鉄の酸化-脱炭について

概要

論文の詳細を見る
In cast iron oxidation is always accompanied by decarburization. The oxidation is influenced by the form, size, and distribution of graphite, and the velocity of oxidation is governed by that of decarburization. The diffusion of oxygen into the matrix takes place more easily in flake graphite cast iron than in SG iron. Particularly, since at higher temperatures above the A1 transition point the diffusion of oxygen is promoted, the oxidation of flake graphite iron is accelerated the more. Decarburization began at a temperature of 550°C, which coincided with the temperature at which the combustion of graphite present in cast iron started. The velocity of decarburization was increased with increasing temperature until it reached the A1 point where the decarburization was once retarded. This tend was more remarkable in flake graphite iron. The scale formed on the surface of cast iron consisted of three layers of different oxides. In the case of flake graphite iron, scale was thick and porous, while in the case of SG iron it being thin and dense. The scale was scanned by a X-ray microanalyzer. The result indicated that there were differences in concentrations of iron and silicon among three layers of the scale. The heterogenity is more marked in flake graphite iron than in SG iron.
Japan Foundry Engineering Societyの論文