溶融 Zn-6mass%Al 浴に浸漬した炭素鋼の界面反応挙動に及ぼす炭素濃度の影響 [in Japanese] Effect of Carbon Content on the Reaction Behavior of Hot Dipped Carbon Steel in Molten Zn-6mass%Al Bath [in Japanese]
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The phases and microstructure of the alloy layer formed during hot dipping of carbon steels in molten Zn-Al bath were investigated. Pure iron, 0.2%C and 0.82%C steels and 2.45%C cast iron were used. A plate shape specimen of 300μm in thickness was firstly hot dipped in a molten Zn bath for 3s and then hot dipped in a molten Zn-6mass%Al alloy bath for certain times, and quenched with water. The microstructure of the quenched specimen was observed by using a SEM, and change in thickness of the specimen was measured by using a laser microscope. The pure iron specimen was entirely changed to an intermetallic compound of Fe<sub>2</sub>Al<sub>5</sub>(Zn) phase after 1.2ks hot dipping. The thickness of 0.2%C steel specimen was decreased linearly with the dipping time after an early non-reaction period, and 2/3 of the specimen was changed to the Fe<sub>2</sub>Al<sub>5</sub>(Zn) phase after 3.6ks hot dipping. It was observed that primarily precipitated ferrite phase preferentially reacted and pearlite structure scarcely reacted. The reacted thickness of the 0.82%C steel and cast iron specimens were only several μm after 86.4Ks hot dipping. In the cast iron specimen, cementite reacted with Al and an Al<sub>3</sub>C<sub>4</sub> phase was formed. The growth of the alloy layer was restricted by the Al<sub>3</sub>C<sub>4</sub> phase. A heat-treated 0.2%C steel specimen with sorbite structure also exhibited the same low reaction behavior as the 0.82% C steel due to homogenized ferrite + cementite structure.
- Journal of The Surface Finishing Society of Japan
Journal of The Surface Finishing Society of Japan 53(2), 129-133, 2002-02-01
The Surface Finishing Society of Japan