亜鉛蒸気の反応性に関する研究 (第1報)
鉄および炭素鋼への亜鉛蒸気の拡散
1967 年 83 巻 952 号 p. 1011-1015
詳細
1967 年 83 巻 952 号 p. 1011-1015
To determine the applicability of metallic materials for equipment which would be exposed only to zinc vapor, the corrosion resistance of pure iron and carbon steels to zinc vapor was investigated in 150-hr. exposure in the temperature range from 900° to 1000°C. The concentration gradients of zinc in the diffused layer after experiments were analysed by an electron probe micro-analyser, and then the diffusion coefficients and activation energies were calculated.
The diffusion coefficients of zinc vapor in the Fe-Zn system, increased with the increase of the zinc content, were obtained at the order of 10-10cm2/sec in the temperature range from 900° to 1000°C, and decreased largely by adding 0.25%C or more into pure iron. The activation energy of diffusion in pure iron was about 5400cal/mol.
From the abrupt change in diffusion penetration curve, it was suggested that the limits of the γ loop.(γ change to α) in the Fe-Zn system was smaller than that indicated in the Fe-Zn diagram by H. H. Stadelrriaier and R. K. Bridgers.
Also, the activity of zinc in the Fe-Zn system was calculated from the surface concentration and the temperature of sample and zinc bath. It was observed that the activity of zinc deviated in a positive direction from ideality and the degree of the deviation decreased with temperature decreasing.
