The component for external surface of the automobile body of the Al - Si - Mg alloy board make which is locked vis-a-vis steel structure

摘要

This invention to be something which deals with the component for external surface of the body of the automobile of the thickness which is included between 0.8mm and 1.2mm, constitution (weight %), Si: 0.7-1.3 Fe0.5 Cu: 0.5-1.1 Mn: 0.4-1.0 Mg: As for the 0.6-1.2 Zn0.7 Cr0.25 Zr+Ti0.20 other element each one 0.15, as for remainder the aluminum, with the alloy make, after the aging processing of 3 weeks at solution heat treatment, sudden cooling, and room temperature, under 170MPa and displays the limit of elasticity R under 160MPa_0.2 desirably 0.05 and altogether. The component for external surface which relates to this invention, when being locked to steel structure before the painting, shows the action which is improved vis-a-vis the expansion difference of the steel, it is ideal in the roof panel of the automobile body.