Reduction annealing and heat plating process of band steel continuous heat plating rare earth aluminium zinc alloy

Abstract

The invention discloses a reduction annealing and heat plating process of band steel continuous heat plating rare earth aluminium zinc alloy, comprising a reduction annealing process and a heat plating process of the band steel continuous heat plating rare earth aluminium zinc alloy. In the invention, through determining that the rare earth aluminium zinc alloy is a band steel plating layer, the wetting property of the aluminium zinc alloy to the surface of band steel and the fluidity of a zinc solution can be enhanced by the rare earth; a best electrochemical protective membrane is formed on the surface of the band steel plating layer; through dividing the reduction heating segment into a front segment and a rear segment, the recrystallization temperature of the band steel can be rapidly raised, and the surface of the band steel is reduced to be smooth; and through respectively arranging an air inlet and an air outlet at the bottom of a hot tensioning segment and / or a cooling segment, and the top of the front reduction heating segment, a dew point value is lowered, and the protective gas in a furnace is improved, thus the band steel before entering a zinc pot has an active surface. By utilizing the technical scheme, the technique of band steel continuous heat plating zinc is further promoted, thus obviously improving the chemical corrosion resistance and electrochemical corrosion resistance of the heat plating zinc band steel, and playing a positive role in broadening the application fields such as the automobile industry and the like of the heat plating zinc band steel made in China.

Description

Technical field: [0001] The invention relates to a strip steel galvanizing process, in particular to a strip steel hot-dip rare earth zinc-aluminum process. Background technique: [0002] The continuous hot-dip galvanizing process of strip steel is the process of uncoiling, welding, degreasing, reduction annealing, hot-dip plating, skin-pass leveling, surface treatment, and winding of strip steel in sequence. [0003] The reduction annealing process is a process of annealing the deformed steel strip at elevated temperature and recrystallizing to eliminate internal stress and restore plasticity. According to the difference between the strip galvanizing requirements and the strip material, especially the strip galvanizing requirements, there are six process sections for strip preheating, reduction heating, reduction soaking, cooling, equalization, and thermal tension. , Or, it is divided into four process sections of strip reduction heating, reduction soaking, cooling, and th...

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Problems solved by technology

[0005] The raw material for traditional strip coating is zinc or zinc-aluminum alloy. Due to the poor fluidity of the zinc solution, not only the surface of the strip coated with zinc or zinc-aluminum alloy is obviously rough, but also the strip is hot-dipped during the hot-dip process. Or the wettability of zinc-aluminum alloy to steel is not ideal enough, the zinc liquid is difficult to penetrate the steel base, and the strip steel coating made of zinc or zinc-aluminum alloy cannot adhere firmly to the steel base, that is to say, the The strip steel coating made of aluminum alloy cannot be firmly attached to the surface of the strip steel, and even in the chemical corrosion and electrochemical corrosion environment, the strip steel coating made of zinc or zinc aluminum alloy will produce peeling phenomenon

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