Aluminum alloy sheet having good formability

Abstract

Provided is a 6000-series aluminum alloy sheet having good formability for an automotive body panel, which can be manufactured without greatly varying an existing composition or an existing manufacturing condition. The amount of solute Si and the amount of solute Cu in an Al-Mg-Si aluminum alloy sheet are increased in a balanced manner, so that the sheet has a dislocation density within a specific range when tensile deformation in a low-strain region is applied to the sheet. This suppresses localization of dislocations introduced into a material due to tensile deformation during press forming into an automotive body panel, and allows dislocations to be evenly multiplied from the low-strain region to a high-strain region. Consequently, uneven deformation is suppressed during forming into the automotive body panel, and good work hardenability is exhibited.

Description

technical field [0001] The present invention relates to an Al-Mg-Si-based aluminum alloy sheet excellent in formability. The aluminum alloy sheet referred to in the present invention is a rolled sheet such as a hot-rolled sheet or a cold-rolled sheet, and refers to a member or sheet to be used after being subjected to quenching and tempering such as solution treatment and quenching treatment. Aluminum alloy plate before painting and baking hardening. In addition, in the following description, aluminum is also called Al. Background technique [0002] In recent years, social demands for reducing the weight of automobiles and other vehicles have been increasing due to considerations such as the global environment. In order to meet this demand, as a material for automobiles, instead of steel materials such as steel sheets, aluminum alloy materials with excellent formability and coating bake hardening (Bake Hardness, hereinafter also referred to as BH) and lighter weight appli...

AI Technical Summary

Problems solved by technology

Therefore, although the combination of formability is also taken into consideration, the level does not exceed the range of the usual hemming workability and press formability, and it does not achieve such a strict high formability that is required for the panel materials of automobiles in recent years. sexual purpose

[0022] Therefore, in order to achieve the strict high formability required for such automotive panel applications, the actual situation so far has been to take well-known countermeasures in the past, that is, to change the panel design and change the forming conditions to ease the stress during forming. Load, or reduce the strength of the 6000 series aluminum alloy plate during forming, etc.

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