High-temperature batch hot-dip galvanizing .1. General description of coatings formed at 560 degrees C
High-temperature batch hot-dip galvanizing .1. General description of coatings formed at 560 degrees C
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DOI:
10.1016/s0257-8972(96)02941-6
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发表时间:
1997-02-15
影响因子:
5.4
通讯作者:
vanOoij, WJ
中科院分区:
文献类型:
--
作者:
Verma, ARB;vanOoij, WJ
The batch high temperature hot-dip galvanizing (HT-HDG) process of silicon-killed steels was studied. Cold-rolled (CRS) and hot-rolled (HRS) structural steel panels were galvanized in a commercial kettle at immersion times ranging from 3 to 15 min at 560 degrees C. The thickness of the coatings and phase distribution was not strongly dependent on the immersion time or the type of steel used. The coatings formed at this temperature were found to be fully alloyed. However, in certain cases the flux film seemed to inhibit the complete alloying of the HT-HDG coatings. The coating consisted primarily of the delta alloy with smaller amounts of the zeta and the Gamma ahoy. The latter was present only in small amounts at the zinc-steel interface. The surface of these alloy coatings consisted of small monoclinic crystals of the zeta alloy embedded in a layer which is a solid solution of the delta and zeta alloy. This surface was microporous. The microporous surface of the coatings enhanced paintability. The corrosion resistance of these coatings was equal if not better than conventional coatings.The hardness values of the HT-HDG coatings was higher compared to the conventional coatings. The alloyed surface of this coating renders it suitable for applications where abrasion and wear resistance are of significant importance.