Hot-dipped galvanized steel material having excellent weldability and press workability and manufacturing method therefor

Abstract

Disclosed are a hot-dipped galvanized steel material and a method for manufacturing the same. The hot-dipped galvanized steel material comprises an iron substrate and a hot-dipped galvanizing layer formed on the iron substrate, wherein the hot-dipped galvanizing layer comprises, by wt%, 0.01 to 0.5% of Al, 0.01 to 1.5% of Mg, 0.05 to 1.5% of Mn, 0.1 to 6% of Fe, and the balance of Zn and inevitable impurities, with a Zn-Fe-Mn based alloy phase present at the interface between the iron substrate and the hot-dipped galvanizing layer, and an area ratio of the Zn-Fe-Mn-based alloy phase to the hot-dipped galvanizing layer ranging from 1 to 60%.

Description

technical field [0001] The present invention relates to a hot-dip galvanized steel material excellent in weldability and press workability, and a method for producing the same. Background technique [0002] Since hot-dip galvanized steel has a lower corrosion potential than iron, it has the characteristics of sacrificial corrosion protection (Sacrificial Corrosion Protection) that corrodes earlier than iron in a corrosive environment and suppresses the corrosion of steel. Therefore, it is used in automobiles, home appliances, and building materials. demand is increasing. [0003] However, air pollution and deterioration of the corrosive environment due to industrial sophistication are increasing, and due to strict regulations on resources and energy saving, it is necessary to develop steel materials with better corrosion resistance than existing galvanized steel materials. [0004] In order to improve the corrosion resistance, various studies have been made on adding elemen...

AI Technical Summary

Problems solved by technology

Galvalume, a representative galvanized alloy-based steel, contains 55% by weight of Al and 1.6% by weight of Si. In order to manufacture this steel, the temperature of the plating bath needs to be maintained at 600°C or higher. The alloy phase of iron and zinc degrades the plating quality and reduces the workability of the plating, which accelerates the corrosion of the internal equipment of the plating bath such as the sink roll and shortens the life of the equipment

[0009] However, in Patent Document 3, a relatively high Al content is maintained relative to the Mg content, thereby forming a primary Al single-phase structure in the plating layer, resulting in poor processability and weldability of the plated material

In addition, in Patent Document 4, a relatively high Mg content is maintained relative to the Al content, thereby inducing hexagonal MgZn 2 The coarsening of the single-phase structure, the formed MgZn 2 The hardness of the single-phase structure is very high, so there is a problem that the corrosion resistance of the processed part and the cross-section part such as cracks in the plating layer when processing the plated material is poor

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