Local heat treatment system and cold forming method using the same

Abstract

The present disclosure relates to a local heat treatment system and a cold forming method using the same. The local heat treatment system includes a heating device configured to locally heat only a plastic deformation occurrence portion of a blank material to a predetermined temperature, a moving device configured to move the heating device to a position of a local heating region of the blank material, and a controller configured to control the heating device and the moving device.

Description

TECHNICAL FIELD[0001]The present disclosure relates to a local heat treatment system and a cold forming method using the same, and more particularly, to a local heat treatment system and a cold forming method using the same capable of improving the formability of an ultra-high tensile steel sheet and minimizing the springback phenomenon.BACKGROUND ART[0002]In general, weight reduction of automobiles is effective for improving automobile fuel economy, and thus, the use of a high-tensile steel sheet, which is a material having a high specific strength, is increasing in recent years. The strength of such a high-tensile steel sheet is improving, and in recent years, an ultra-high tensile steel sheet having a tensile strength of 1 GPa or more has also been developed.[0003]Because the ultra-high tensile steel sheet has a high strength, press molding of the ultra-high tensile steel sheet is not easy, so that it is easy to cause seizing due to increased molding load and increased mold wear,...

AI Technical Summary

Benefits of technology

[0017]A local heat treatment system according to an embodiment of the present disclosure and a cold forming method using the same can improve formability of a material by selectively heating the material locally using an external heat source and then cooling the material to adjust physical properties thereof.

[0018]Further, by locally heating only a part to be plastically deformed so that the physical properties are adjusted, a molding load can be reduced, so that the wear of the mold can be minimized during cold forming and springback phenomenon can be minimized after the cold forming.

[0019]Further, compared to conventional hot forming, productivity and quality can be improved, as well as energy cost can be reduced.

[0020]Further, as artificial intelligence (AI) and sensing technology are combined, the process can be easily and quickly performed when the material is locally heated, thereby improving productivity, and the local heat treatment system can be conveniently applied even when the material has a complex molding shape

Problems solved by technology

Because the ultra-high tensile steel sheet has a high strength, press molding of the ultra-high tensile steel sheet is not easy, so that it is easy to cause seizing due to increased molding load and increased mold wear, and the springback at which the molded shape returns is large, and thus the shape fixability is deteriorated.

In addition, the ultra-high tensile steel sheet has a low ductility and tends to crack when a tensile stress is applied during molding.

However, this method of heating the entire difficult-to-form material may cause unnecessary energy loss by heating even a region where molding is not performed.

However, because this method is to warm a material after heating the material in a warm forming process, the productivity due to the heating time decreases, and during material handling, the local heating part cools quickly, making it difficult to maintain a constant quality.

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