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Vol.50, No.8, 575 ~ 583, 2012
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| Title |
| Characterization of Microstructure, Hardness and Oxidation Behavior of Carbon Steels Hot Dipped in Al and Al-1 at% Si Molten Baths |
| Trinh Van Trung , Sun Kyu Kim , Min Jung Kim , Seul Ki Kim , Sung Jun Bong , Dong Bok Lee |
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| Abstract |
| Medium carbon steel was aluminized by hot dipping into molten Al or Al-1 at% Si baths. After hot-dipping in these baths, a thin Al-rich topcoat and a thick alloy layer rich in Al5Fe2 formed on the surface. A small amount of FeAl and Al3Fe was incorporated in the alloy layer. Silicon from the Al-1 at% Si bath was uniformly distributed throughout the entire coating. The hot dipping increased the microhardness of the steel by about 8 times. Heating at 700-1000, however, decreased the microhardness through interdiffusion between the coating and the substrate. The oxidation at 700-1000 in air formed a thin protective a-Al2O3 layer, which provided good oxidation resistance. Silicon was oxidized to amorphous silica, exhibiting a glassy oxide surface. |
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| Key Words |
| Metals, surface modification, microstructure, scanning electron microscopy (SEM), hot-dip aluminizing |
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