Zinc-plated hot-formed steel plate or steel strip with excellent cold bending performance and manufacturing method thereof

Abstract

The invention discloses a zinc-plated hot-formed steel plate or steel strip with excellent cold bending performance and a manufacturing method thereof. The zinc-plated hot-formed steel plate or steelstrip comprises a base plate with a surface decarburization layer thickness of 20 [mu]m or below and a zinc coating with an adhesion amount of 10-100 g / m<2> on the base plate. The constituent weight percentage of the base plate is C: 0.1-0.8%, Si: 0.05-2.0%, Mn: 0.5-3.0%, P: <=0.1%, S: <=0.05%, Al: <=0.1%, N: <=0.01%, and the balance Fe and unavoidable impurities. The average size of original austenite grains of the base plate is 15 [mu]m or below. The hot-formed steel plate or steel strip has a continuous and complete coating, no cracks extending to the base plate and excellent cold bending performance on the basis of meeting the conditions that the tensile strength of the base plate after hot-forming is 1500 MPa and the elongation after breaking is 5%.

Description

technical field [0001] The invention relates to the field of metal materials, in particular to a zinc-based coated thermoformed steel sheet or steel strip with excellent cold bending performance and a manufacturing method thereof, which are mainly used in the manufacture of structural components such as automobile B-pillars, door anti-collision beams, and bumpers. . Background technique [0002] The development trend of light weight, safety and low energy consumption of automobiles has promoted the development of high-strength steel plates. The use of advanced ultra-high-strength steel to replace traditional low-strength steel plates has become inevitable, and the use of high-strength steel plates can also significantly improve the crash safety of automobiles. However, with the improvement of the strength of the steel plate, the difficulty of processing the parts is also increasing. For the stamping forming process, thinning and high strength are the dual factors that dete...

AI Technical Summary

Problems solved by technology

However, with the extensive application of hot stamping steel, the requirements for the collision performance of parts after hot stamping, such as cold bending performance and impact toughness, have also increased accordingly, and traditional hot stamping steel cannot meet the demand

[0003] In addition, during the heating process of traditional uncoated hot stamping parts, the surface of the stamped steel plate will be oxidized and peeled, and the oxide scale will increase the friction coefficient between the steel plate and the mold and reduce the service life of the mold. reduced productivity

In order to meet the subsequent processing requirements of stamping parts, it is necessary to remove the oxide scale formed on the surface by shot peening. The shot peening process causes tiny cracks on the surface of stamping parts, which limits the production and use

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