What is ISO 24284 - Corrosion test method for decorative chrome plating about?
ISO 24284 discusses metallic coatings. Metallic coatings contain a metallic element or alloy. Metallic coatings can be applied by using a sprayer, electrochemically, chemically, or mechanically. ISO 24284 specifies the apparatus, reagents, and procedure to assess the corrosion resistance of chromium electroplated parts in the presence of de-icing salts (especially calcium chloride) in the laboratory.
This method is primarily applicable to decorative parts plated with chromium, especially to exterior (automobile) parts electroplated with nickel-chromium or copper-nickel-chromium. ISO 24284 simulates special corrosion in the presence of hygroscopic and corrosive de-icing salt and conductive mud with a high salt concentration on chromium electroplated deposits during winter.
Who is ISO 24284 - Corrosion test method for decorative chrome plating for?
ISO 24284 on the corrosion test method for decorative chrome plating is useful for:
- Steel manufacturing industries
- Metal plating sector
- Quality control personnel
- Chemical industries
Why should you use ISO 24284 - Corrosion test method for decorative chrome plating?
Decorative, electrodeposited nickel-chromium and copper-nickel-chromium coatings, built up with a multilayer nickel system including micro-discontinuous nickel, are applied to manufactured articles to enhance their appearance and corrosion resistance. These coating systems are characterized by unique corrosion mechanisms. Once corrosion begins, the nickel layer gets dissolved preferentially (especially in the case of a bright nickel layer): it acts as an anode with respect to chromium (which is intended to act as a cathode). In addition, lots of tiny pores or cracks in the micro-discontinuous layer distribute the corrosion current throughout the whole surface. In this way, the amount of current at a given corrosion site is substantially lowered, creating minor pits that remain for a longer time invisible to the naked eye.
In addition, the corrosion penetration through the bright nickel layer is reduced, especially when a more noble semi-bright nickel layer shields it from the substrate or the copper underlayer. An additional different corrosion phenomenon is caused during winter by de-icing salts, especially calcium chloride. This particular corrosion phenomenon is characterized by slightly yellow and less shiny spots on the surface, caused by the complete dissolution of the chromium layer and the partial deterioration of the microporous nickel layer. In this situation, the bright nickel layer remains intact. Such corrosion phenomena are predominantly occurring in areas with cold winter conditions and the use of calcium chloride as a de-icing agent in combination with dirt dust deposits. Using ISO 24284 you can specify the apparatus, reagents, and procedure to assess the corrosion resistance of chromium electroplated parts in the presence of de-icing salts (especially calcium chloride) in the laboratory.
