Анотація
This specification covers the chemical and anodic treatments used to prepare magnesium alloy surfaces for printing. The procedures for preliminary surface treatment using alkaline and acidic cleaners are described. Class I Type I (chrome pickle) surface treatment procedure is applicable to all forms of magnesium, except for certain special alloys containing silver. I class II (seal cr kimchi) surface treatment procedures are applicable to all types and forms of magnesium alloy, only restricted by the I class I class to handle. Type I and type III processing are applicable to all types and forms of magnesium alloy, but the M1 alloy and some similar to EK30A except for rare earth alloy. Class II Type I (electroplated dichromate treatment) produces a black coating with good protective and analgesic qualities for all alloys and forms of magnesium, including the M1 alloy. Class II, Type II treatment is applicable to all forms and alloys of magnesium. Class II, Type III treatment is applicable to all forms and alloys of magnesium without attachments or inserts of other metals.

ASTM D1732-2018 “Обробка поверхні магнієвих сплавів для фарбування”

The concept
1.1 These practices cover two classes of treatments used to prepare magnesium alloy surfaces for coating, наступним чином:

The first category – chemical treatment.

The second category – anodic treatment.

В загальному, the latter treatment is more protective in both categories. Mechanical (abrasive) лікування, solvent cleaning, alkaline solution treatment, and acid pickle do not result in protective conversion coatings are preliminary treatments suitable for metals exposed only under mild corrosive (indoor) exposure. When you need a high degree of corrosion protection and paint adhesion, such as in many outdoor environment, surface treatment using conversion coating is one of the categories above. The use of a method based on hexavalent chromium is not recommended because hexavalent chromium is a known carcinogen.

Примітка 1: Coating tests – Quality control tests for coatings are usually desirable. These tests usually include exposure to salt spray, humidity or the natural environment, with or without paint, and have procedures in place to assess the degree of breakdown suffered after fixed time intervals. Coating quality control testing is recommended to use high-purity materials such as AZ31A alloy whenever possible, 2 whose inherent corrosion rate varies from batch to batch, and precautions should be taken to remove surface contaminants prior to coating application. Such contaminants should be removed by pickling to a depth of at least 0.001 inches (25 мікрометри) on each side.

ASTM D1732-2018 “Обробка поверхні магнієвих сплавів для фарбування”

1.2 this standard may involve hazardous materials, operations, and equipment. Цей стандарт не призначений для вирішення всіх питань безпеки, якщо хто-небудь, пов'язані з його використанням. Відповідальність за встановлення належної безпеки несе користувач цього стандарту, здоров’я та навколишнього середовища, а також для визначення застосовності нормативних обмежень перед використанням. See note 11.

1.3 Цей міжнародний стандарт розроблено відповідно до міжнародно визнаних принципів стандартизації, встановлених у Рішенні про принципи розробки міжнародних стандартів., Настанови та рекомендації, видані Комітетом з технічних бар’єрів у торгівлі Світової організації торгівлі.