High-strength hot-dip galvanized steel sheet reduced in burr formation and process for producing same

Abstract

There are provided a high-strength galvanized steel sheet having excellent anti-burring performance with a low burr height and a method for manufacturing high-strength galvanized steel sheet. The high-strength galvanized steel sheet having excellent anti-burring performance contains C: 0.04% or more and 0.13% or less, Si: 1.0% or more and 2.3% or less, Mn: 0.8% or more and 2.0% or less, P: 0.05% or less, S: 0.0010% or more and 0.01% or less, Al: 0.1% or less, and N: 0.008% or less on a mass percent basis, and the remainder of Fe and incidental impurities, wherein a ferrite phase constitutes 75% or more, a bainitic ferrite phase constitutes 1% or more, a pearlite phase constitutes 1% or more and 10% or less, and a martensite phase constitutes less than 5% on an area ratio basis, and the area ratio of the martensite phase / (the area ratio of the bainitic ferrite phase + the area ratio of the pearlite phase) is 0.5 or less.

Description

technical field [0001] The present invention relates to a steel sheet excellent in burr resistance during processing, which is used after punching, shearing, etc., for automobiles, home appliances, etc., and a method for producing the same. Background technique [0002] Thin steel sheets are widely used for automobiles, home appliances, furniture, etc., but generally, they are finished into desired products or parts in the order of blank processing-forming-assembly. In recent years, against the background of the complexity and high functionality of products, the requirements for machining accuracy have become increasingly strict. In terms of raw materials, what degrades machining accuracy is the burr that occurs on the end surface during punching. If the burr is large, it will cause fatal accuracy degradation in the final assembly stage. Furthermore, in the case of automobiles, there is a possibility that a gap may be generated in a superimposed portion between steel sheets...

AI Technical Summary

Problems solved by technology

In terms of raw materials, what degrades machining accuracy is the burr that occurs on the end surface during punching. If the burr is large, it will cause fatal accuracy degradation in the final assembly stage.

In addition, in the case of automobiles, there may be serious effects on functions such as the occurrence of gaps in the superimposed part of the steel plates and the deterioration of corrosion resistance.

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