意义及用途
5.1 该测试方法最初是为了研究和开发目的而开发的; 然而, 在特定的材料规格, it is referenced to evaluate production materials (see section 14 on accuracy and deviation).

5.2 Using this test method can effectively predict the spalling corrosion behavior of these alloys in various types of outdoor services, especially in Marine and industrial environments. The four-test solution is highly corrosive and represents a more stringent type of environmental service, and certainly does not include unusual chemicals that are unlikely to be encountered in the natural environment.

5.3 Exfoliation grades were chosen arbitrarily in this test to illustrate the wide range of resistance to exfoliation. 然而, it remains to be determined whether a correlation can be established between EXCO test ratings and the actual conditions of use for a given alloy. The Aluminium Alloy Peeling Corrosion Working Group (G01.05.02.08) is conducting an activity to conduct outdoor exposure testing for this purpose. 例如, it has been reported that Al-Zn-Mg-Cu alloy samples rated EA or P in the 48-hour EXCO test did not experience more than a small amount of early peeling (EA) during six to nine years of exposure to the coastal atmosphere, while in most cases ED grade materials showed significant peeling within a year in the coastal atmosphere. It is expected that more comparisons will be provided as outdoor testing expands.

ASTM G34-2020 循环湿热腐蚀测试方法

半径
1.1 This test method covers a constant immersion exfoliation corrosion (EXCO) test procedure for high strength 2XXX and 7XXX series aluminum alloys.

笔记 1: This test method was originally developed for research and development purposes; 然而, 在特定的材料规格, it is referred to as applicable for evaluating production materials (see section 14, “Accuracy and Deviation”).

1.2 This test method is applicable to all forged products, such as sheets, plates, extrusions and forgings produced by conventional ingot metallurgy processes.

1.3 The test method can be used on any form of sample or part that can be immersed in the test solution.

1.4 本标准并非旨在解决所有安全问题, 如果有的话, 与其使用相关. 本标准的使用者有责任建立适当的安全机制, 健康和环境实践，并在使用前确定监管限制的适用性.

1.5 本国际标准基于《关于制定国际标准的原则的决定》中确立的国际公认的标准化原则, 世贸组织贸易技术壁垒委员会发布的指南和建议.