Standards and Specifications
SHERART – standards
At SHERART, QUALITY IS THE STANDARD!
Dr. Frank Natrup
Technical Director
ISO 17668
This International Standard specifies minimum thickness requirements for six classes of zinc diffusion layers applied to ferrous products through the sherardization process.
It does not specify requirements for the surface condition (finish or roughness) of the base material before sherardization.
This standard replaces EN 13811.
ISO 14713-1
This standard provides guidelines and recommendations on the general design principles applicable to galvanized products. All this to protect against corrosion.
In this guideline the degree of corrosion resistance that the zinc coatings offer (when applied to iron and steel objects in different environments) is determined.
ISO 14713-1 relates to zinc coatings that are applied with the following processes:
A) Hot dip galvanized coatings (applied after fabrication)
B) Hot dip galvanized coatings (applied to continuous sheets)
C) Coatings applied by sherardizing
D) Coatings applied by thermal spraying
E) Mechanically applied zinc coatings
F) Coatings applied by electrolytic deposition
ISO 14713-3
Guidelines and recommendations for the protection of iron and steel in structures against corrosion – Zinc coatings – Part 3 Sherardizing
EN 13438
This European Standard specifies performance requirements for organic coating powders and organic powder coatings applied to finished articles (galvanized or sherardized steel products) for construction purposes.
This standard provides advice on how to clean and pre-treat the galvanized or sherardized steel products before powder coating.
EN 15773
This European Standard specifies the agreements between the client, the sherardizer, the chemical suppliers and the applicators of the pre-treatment systems and the organic powder coating systems (if they are not the same).
The standard deals with the quality of the galvanized or sherardised objects to which the powder coatings are applied. As well as the pre-treatment and organic powder coatings to be applied to the galvanized or sherardized objects.
This standard applies to the application of hot dip galvanized and sherardized coatings and organic powder coatings by controlled industrial processes on products consisting of or made of steel.
ISO 12944-5
ISO 12944 describes the types of paint and paint systems commonly used for corrosion protection of steel structures.
The standard provides guidelines for the selection of paint systems (applicable to different environments), surface preparation and the durability class to be expected (low, medium or high).
ISO 9227
In a salt spray test according to ISO 9227, corrosion occurs relatively quickly in any galvanized or diffusion galvanized coating. This while in nature, depending on the layer thickness, it is resistant to rust formation for longer than tested. The explanation? In these accelerated tests, the zinc layer cannot build up a protective patina layer, which explains the rapid failure.
According to ISO 14713, accelerated corrosion tests on zinc coatings do not correlate with real practice observations.
With the application of a passivation or a topcoat, an additional passive protection is applied, so that even thin zinc layers achieve excellent results in a salt spray test. The quick test revials the closedness of the passivation and the connectedness of the entire system. In practice, the topcoat protects the active protective layer until it is damaged by cracks, scratches or mechanical influences. At that moment, the basecoat itself actively fills the impurities that have arisen and the protection remains intact. Duplex systems are therefore significantly stronger than single zinc coatings.
ISO 9001
With this certificate, SHERART demonstrates that products and services are consistently delivered that meet the required quality of the customers.
