Iron-zinc coated steel plate with yield strength being 210 MPa and production method thereof

Abstract

An iron-zinc coated steel plate with the yield strength being 210 MPa comprises chemical compositions including, by weight, 0.03-0.04% of C, 0.007-0.015% of Si, 0.32-0.4% of Mn, less than or equal to 0.02% of P, less than or equal to 0.01% of S, 0.015-0.05% of Als and less than or equal to 0.05% of N. The production method comprises the production steps that continuous hot-dip galvanizing is conducted on a cold-rolled steel plate; the steel plate is sent to an iron-zinc diffusion treatment heating furnace by taking insulation measures; the galvanized steel plate is subjected to high-temperature zinc-iron diffusion treatment first and then low-temperature zinc-iron diffusion treatment; and the steel plate is cooled naturally to the roor temperature for standby application. By means of the production method, on the premise of guaranteeing the application mechanics of the steel plate, a galvanneal coating can be compact in surface structure and free of obvious microcrack defects, and zinc-iron grains on the surface of the coating are fine and uniform in size distribution. The coating is bound firmly to a steel base plate. The coating is not prone to pulverization and shedding during stamping forming.

Description

technical field [0001] The invention relates to a galvanized steel plate and a production method thereof, in particular to an iron-zinc coated steel plate with a yield strength of 210 MPa and a production method thereof, and is suitable for a steel plate with a thickness of 0.7-1.2 mm. Background technique [0002] Zinc-iron coated steel sheet (GA) has excellent corrosion resistance, paintability, weldability and anti-gravel performance, and is widely used in automobile panels. However, zinc slag and zinc ash are prone to appear on the surface of the coating, and the iron content and phase structure of the coating cross-section are unevenly distributed. Defects such as shedding and pulverization of the coating are prone to occur during stamping and forming, which will affect the surface quality of stamping parts and production molds. Negative Effects. [0003] After patent search, a production method of non-powdering thick-gauge zinc-iron alloyed plate was found. The strip ...

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Problems solved by technology

If a fully enclosed alloying furnace is used, the one-step heating method can be used, but the investment of this equipment is high, the equipment is complicated, and the cost of maintenance and accessories is also high

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