A cyclic heat treatment method for improving the paint performance of aluminum alloy automotive panels

Abstract

The invention belongs to the technical field of aluminum alloy automobile sheet treatment processes, and discloses a circulating heat treatment method for improving the performance of stoving varnishof an aluminum alloy automobile sheet. A 6000-series aluminum alloy cold-rolled sheet is subjected to solution treatment for 20 min to 30 min under the condition with the temperature ranging from 530DEG C to 550 DEG C and then is immediately quenched in cold water; a sample subjected to solid solution-quenching is immediately put in an aging oven with the temperature ranging from 160 DEG C to 180DEG C to be subjected to heat preservation for 40 min to 60 min; the aged sample is subjected to solution treatment for 20 min to 30 min under the condition with the temperature ranging from 530 DEGC to 550 DEG C and is immediately quenched in cold water; and the sample subjected to secondary solid solution-quenching is immediately put in the aging oven to be subjected to pre-aging treatment for10 min to 20 min under the condition with the temperature ranging from 90 DEG C to 110 DEG C. In the method, beta phases are evenly separated out in an aluminum alloy matrix through heat treatment ofthe first stage; through pre-aging in heat treatment of the second stage, natural aging is restrained, and more phase cores are formed; and in the stoving varnish hardening process, the beta cores cannot be dissolved and are converted into dispersed and fine beta phases, and the stoving varnish strengthening effect is further improved.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloy automobile sheet processing technology, and in particular relates to a cyclic heat treatment method for improving the paint performance of aluminum alloy automobile sheet. Background technique [0002] In response to the national concept of energy saving, emission reduction and green development, automobile lightweight is the main direction of the development of the automobile industry. The 6000 series Al-Mg-Si alloy has some excellent properties, such as sufficient strength, high stiffness to weight ratio, good formability, excellent corrosion resistance, and recyclability, making it a substitute for steel Materials with large proportions such as cast iron and cast iron are applied to various parts of the car to meet the weight reduction requirements of the car. The composition of 6000 series aluminum alloy automotive sheet materials is generally Si: 0.75% ~ 0.10%; Fe: 0.15% ~ 0.23%; Cu: ...

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Problems solved by technology

[0003] To sum up, the problems existing in the prior art are: with the increase of traffic accidents today, the quality of automobile body panels is getting higher and higher, so it is necessary to seek a super-performance aluminum alloy automobile panel, which can be improved by cyclic heat treatment. There are few ways to bake paint properties

This is because the current research methods for improving the performance of baking paint mainly focus on single-stage pre-aging, pre-strain, pre-aging + pre-straining and microalloying, and there is a lack of exploration and research on the method of cyclic heat treatment to improve the performance of baking paint

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