Article ID

2000Bdb1001

Title

Electroless Coating of Fe3Si on Steel in the Molten Salt


Author(s)

R. O. Suzuki, T. Nishibata, K. Nakanishi, M. Ishikawa and K. Ono



Publication/Publisher

steel research, vol.71, No.4, pp. 130-137 (2000)



Abstract


The corrosion-resistive intermetallic compound Fe3Si could non-electrolytically coat pure iron and mild steel. The disproportional reaction between Si and Si4+ ions deposited the homogenous Fe3Si layer on the Fe substrates, by using solid silicon and the molten salt composed of NaCl-KCl-NaF-Na2SiF6-SiO2. SiF4 gas evaporation prevented from continuous siliconization, when only Na2SiF6 was used as Si4+ ion source. By adding SiO2 into the salt as another source, the molten salt became endurable for repeated usage in air. The layer of Fe3Si single phase with 24 +- 1 mol pct Si grew thicker than 200 micro m by immersing for a few hours at 973-1173K.