What is ISO/TR 22770 - colorimetry for steel preparation about?
Colorimetry is a technique used to determine the concentration of colored compounds in solution. ISO/TR 22770 provides guidelines on the usage of analytical colorimetry to support visual assessment of surface preparation grades described in ISO 8501‑1:2007.
ISO/TR 22770 provides examples of applications where the use of a colorimeter or spectrophotometer can enable a quick and objective assessment of the preparation grade of the substrate.
Who is ISO/TR 22770 - colorimetry for steel preparation for?
ISO/TR 22770 on analytical colorimetry for steel preparation is useful for:
- Operators and owners of cast iron foundries
- Product development teams
- Quality control teams
- Manufacturers of products such as: Steel pipes for the oil and gas industry, Trailers, Freight wagons, Cold drawn bars
Why should you use ISO/TR 22770 - colorimetry for steel preparation?
The performance of protective coatings of paint and related products applied to steel is significantly affected by the state of the steel surface immediately prior to painting. The principal factors that are known to influence this performance are:
- the presence of rust and mill scale
- the presence of surface contaminants, including salts, dust, oils, and greases
- the surface profile
Accurate assessment of the state of the substrate enables you to decide on preparation methods which, in turn, affect the quality of coating adhesion. Coating adhesion affects the longevity of the end-product; since it protects the substrate from corrosion.
ISO/TR 22770 provides a tool to aid the visual assessment of rust grades and of preparation grades. ISO/TR 22770 identifies four levels (designated as “rust grades”) of mill scale and rust that are commonly found on surfaces of uncoated erected steel and steel held in stock. It also identifies certain degrees of visual cleanliness (designated as “preparation grades”) after surface preparation of uncoated steel surfaces and of steel surfaces after overall removal of any previous coating.
ISO/TR 22770 provides detailed guidelines for instrument specifications and instrument handling to conduct the colorimetry procedure. Using ISO/TR 22770 guidelines, you would be able to determine the cleanliness of the substrate so that you can prepare the substrate prior to painting. ISO/TR 22770 facilitates accurate preparation of the substrate which, in turn, extends the longevity of the end-product.