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Electroless coating of Fe 3 Si on steel in the molten salt
Author(s) -
Suzuki Ryosuke O.,
Nishibata Toshinobu,
Nakanishi Kohichi,
Ishikawa Masazumi,
Ono Katsutoshi
Publication year - 2000
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.200005702
Subject(s) - molten salt , homogeneous , chemistry , metallurgy , coating , evaporation , silicon , materials science , thermodynamics , physics , organic chemistry
The corrosion‐resistive intermetallic compound Fe 3 Si could non‐electrolytically coat pure iron and mild steel. The disproportional reaction between Si and Si 4+ ions deposited the homogeneous Fe 3 Si layer on the Fe substrates, by using solid silicon and the molten salt composed of NaCl‐KCl‐NaF‐Na 2 SiF6‐SiO 2 . SiF 4 gas evaporation prevented from continuous siliconization, when only Na 2 SiF 6 was used as Si 4+ ion source. By adding SiO 2 into the salt as another source, the molten salt became endurable for repeated usage in air. The layer of Fe 3 Si single phase with silicon mole fractions of 24 ± 1 % grew thicker than 200 μm by immersing for a few hours at 973 – 1173K.