Study On The Microstructure And Properties Of Arc Remelting Hot-dip Aluminum Steel

Hot-dip Aluminum plating is a new anti-corrosion technology follows by the hot-dip Zinc plating, which shows a promising application in petroleum and chemical industry, metallurgy, communication, offing projects, automobile and civil products. But the application of hot-dip Al is limited for the brittleness of plating layer and difficult to machining. Only lucubrates the hot-dip technology, the new hot-dip plating and arc remelting technology can be applied further. This can also promote the production safety and save the production costs.The paper mainly studied the performance of arc remelting hot-dip Al on the steel. The goal of this research was to figure out the problem of too higher brittleness to machine of the hot-dip Al layer, based on the excellent corrosion resistance. The experiment carried out in virtue of the Ar arc remelting, scanning electron microscope (SEM) and X-ray diffraction (XRD) methods. Through the mechanics performance and corrosion resistance tests, the effects of arc remelting parameters on the structure, composition, substance and mechanics-chemistry performance of hot-dip Al layer were investigated.The results showed that the optimum arc remelting parameters including: the welding current was 30 A, the arc potential was 10 V and the welding velocity was 150 mm/min for the hot-dip Al layer with the thickness of 6 mm. There was a obvious layered structure after hot-dip Al plating. The composition of layer was pure Al layer, diffusion layer mainly of Al-Fe compounds and substrate layer, respectively. As opposite to the hot-dip Al layer, the composition of arc remelting hot-dip Al layer was composed of diffusion layer and substrate layer. The micro-hardness of the hot-dip Al layer increased greatly after arc remelting. The friction factor and abrasion weight decreased and the porosity may increased after arc remelting. Besides, the brittleness of arc remelting hot-dip Al layer enhanced surely. There was no obvious bubbles and micro-cracks existed in the surface of arc after remelting bend tests. The corrosion weight of hot-dip Al layer with or without arc remelting increased with the salt spray tests time, but the arc remelting layer exhibited a slightly-increasing tendency.