CEN/TC 262 - Metallic and other inorganic coatings

This document reviews methods for measuring the thickness of metallic and other inorganic coatings on both metallic and non-metallic substrates (see Tables 1, A.1 and A.2). It is limited to tests already specified, or to be specified, in International Standards and excludes certain tests that are used for special applications.

This document specifies the information to be supplied by the purchaser to the finisher, requirements and test methods for electropolishing as a means of smoothing and passivating stainless steel alloys in the S2XXXX, S3XXXX and S4XXXX series, and the precipitation hardened alloys (see ISO 15510 for information on composition).

This document specifies a method for assessing the resistance of materials or products to a humid atmosphere containing sulfur dioxide.
This method is applicable to testing metals and alloys, metallic and non-organic coatings and organic coatings.

ISO 21207:2015 defines two accelerated corrosion test methods to be used in assessing the corrosion resistance of products with metals in environments where there is a significant influence of chloride ions, mainly as sodium chloride from a marine source or by winter road de-icing salt, and of corrosion-promoting gases from industrial or traffic air pollution.
ISO 21207:2015 specifies both the test apparatus and test procedures to be used in executing the accelerated corrosion tests.
The methods are especially suitable for assessing the corrosion resistance of sensitive products with metals, e.g. electronic components, used in traffic and industrial environments.

This International Standard specifies two accelerated corrosion test procedures, Methods A and B, for the evaluation of corrosion behaviour of surface-treated metals and their alloys with and without paint on them in atmospheric environments. It also specifies the apparatus used. The two tests involve salt deposition and dry/wet conditions at a constant absolute humidity.
Method A applies to:
metals and their alloys (including corrosion-resistance alloys)
Method B applies to:
metals and their alloys
metals and their alloys with coatings [including metallic coatings (anodic or cathodic), organic
coatings, and conversion coatings]

This document gives guidance on the selection of test methods for evaluating the performance of vitreous and porcelain enamelled finishes in different applications. This document references the test methods available for measuring the properties of these finishes and correlates these properties to the requirements of specific enamelled articles.
This document is limited for the most part to test methods in ISO documents or European standards but does not provide acceptance criteria or performance limits for the properties.
This document is applicable to all enamelled articles, irrespective of their basis metals.

This document specifies tests which are intended to determine the influence of one or more flowing polluting gas(es) at volume fractions less than or equal to 10−6 on test samples and/or articles of metals and alloys with or without corrosion protection under determined conditions of temperature and relative humidity.
This document is applicable to
a) metals and their alloys,
b) metallic coatings (anodic and cathodic),
c) metals with conversion coatings,
d) metals with anodic oxide coatings, and
e) metals with organic coatings.

This document specifies a simulating method of test for determination of the release of metal-ions from enamelled articles, which are intended to come into contact with food.
This document also specifies limits for the release of metal-ions from enamelled articles, which are intended to come into contact with food.
This document is applicable to enamelled articles, including tanks and vessels, which are intended to be used for the preparation, cooking, serving and storage of food.

This document specifies the apparatus, the reagents and the procedure to be used in conducting the neutral salt spray (NSS), acetic acid salt spray (AASS) and copper-accelerated acetic acid salt spray (CASS) tests for assessment of the corrosion resistance of metallic materials, with or without permanent or temporary corrosion protection.
It also describes the method employed to evaluate the corrosivity of the test cabinet environment.
It does not specify the dimensions or types of test specimens, the exposure period to be used for a particular product, or the interpretation of results. Such details are provided in the appropriate product specifications.
The salt spray tests are particularly useful for detecting discontinuities, such as pores and other defects, in certain metallic, organic, anodic oxide and conversion coatings.
The NSS test is particularly applicable to:
—    metals and their alloys;
—    metallic coatings (anodic and cathodic);
—    conversion coatings;
—    anodic oxide coatings;
—    organic coatings on metallic materials.
The AASS test is especially useful for testing decorative coatings of copper + nickel + chromium, or nickel + chromium. It has also been found suitable for testing anodic and organic coatings on aluminium.
The CASS test is useful for testing decorative coatings of copper + nickel + chromium, or nickel + chromium. It has also been found suitable for testing anodic and organic coatings on aluminium.
The salt spray methods are all suitable for checking that the quality of a metallic material, with or without corrosion protection, is maintained. They are not intended to be used for comparative testing as a means of ranking different materials relative to each other with respect to corrosion resistance or as means of predicting long-term corrosion resistance of the tested material.

This document specifies the requirements for the design and use of vitreous enamel coated bolted cylindrical steel tanks for the storage or treatment of water or municipal or industrial effluents and sludges.
It is applicable to the design of the tank and any associated roof and gives guidance on the requirements for the design of the foundation.
It is applicable where:
a) the tank is cylindrical and is mounted on a load-bearing base substantially at or above ground level;
b) the product of the tank diameter in metres and the wall height in metres lies within the range 5 to 500;
c) the tank diameter does not exceed 100 m and the total wall height does not exceed 50 m;
d) the stored material has the characteristics of a liquid, exerting a negligible frictional force on the tank wall; the stored material can be undergoing treatment as part of a municipal or industrial effluent treatment process;
e) the internal pressure in the headspace above the liquid does not exceed 50 kPa and the internal partial vacuum above the liquid does not exceed 10 kPa;
f) the walls of the tank are vertical;
g) the floor of the tank is substantially flat at its intersection with the wall; the floor of the tank can have a rise or fall built in to allow complete emptying of the tank contents, the slope of which does not exceed 1:100;
h) there is negligible inertial and impact load due to tank filling;
i) the minimum thickness of the tank shell is 1,5 mm;
j) the material used for the manufacture of the steel sheets is carbon steel (tanks constructed of sheets made from aluminium or stainless steel are outside the scope of this document);
k) the temperature of the tank wall during operation is within the range −50 °C to +100 °C under all operating conditions.
This document also gives details of procedures to be followed during installation on site and for inspection and maintenance of the installed tank.
It does not apply to chemical-reaction vessels.
It does not cover resistance to fire.

This document specifies the basic conditions concerning the method for determining the resistance of vitreous and porcelain enamelled articles to heat.
The method specified is applicable to vitreous and porcelain enamelled articles that are, in service, subjected to high temperature, for example, to some cooker components, exhaust pipe silencers, gas heating chimneys and flue pipes.

This document specifies a method for measuring the thickness of the individual nickel layers in electroplated multilayer nickel coatings and measuring the potential differences between the individual nickel layers in electroplated multilayer nickel coatings.
The measurement of coatings or layer systems other than electroplated multilayer nickel coatings is outside the scope of this document.

This document specifies a method of test for determining the scratch hardness of the surface of vitreous and porcelain enamels.

This document specifies a method for determining optical and dielectric constants in the UV-VIS-NIR spectral range as well as layer thicknesses in the field of at-line production control, quality assurance and material development through accredited test laboratories.
It is applicable to stand-alone measuring systems. The presentation of the uncertainty of results conforms to ISO/IEC Guide 98-3.

This document specifies spectroscopic ellipsometry for the determination of optical properties (refractive index n and extinction coefficient k) and the optical classification of different types of amorphous carbon films within the n-k plane.
It is applicable to amorphous carbon films deposited by ionized evaporation, sputtering, arc deposition, plasma-assisted chemical vapour deposition, hot filament techniques and others.
It does not apply to carbon films modified with metals or silicon, amorphous carbon films that have a gradient of composition/property in the thickness, paints and varnishes.

This document specifies a method for non-destructive measurements of the thickness of conductive coatings on non-conductive base materials. This method is based on the principle of the sheet resistivity measurement and is applicable to any conductive coatings and layers of metal and semiconductor materials. In general, the probe has to be adjusted to the conductivity and the thickness of the respective application. However, this document focuses on metallic coatings on non-conductive base materials (e.g. copper on plastic substrates, printed circuit boards).
This method is also applicable to thickness measurements of conductive coatings on conductive base materials, if the resistivity of the coating and the base material is significantly different. However, this case is not considered in this document.

This document specifies a test method for the determination of the crack formation temperature of enamels for the chemical industry by subjecting enamelled steel specimens to thermal shock using cold water.
The value of the crack formation temperature measured according to this test method does not apply to the finished component (see Annex A). It is a parameter of vitreous and porcelain enamels for comparing the relative quality of different enamel formulations.

This document defines the terms related to the general types of surface-finishing processes. Emphasis is placed on practical usage in surface-finishing technology in the metal-finishing field.
This document does not include terms for porcelain and vitreous enamel, thermally sprayed coatings and galvanising for which specialized vocabularies and glossaries exist. For the most part, basic terms that have the same meaning in surface finishing as in other fields of technology, and that are defined in handbooks and dictionaries of chemistry and physics, are not included.

Specifies a test method which is used as a factory production control test. The test is not intended to be used for testing the adhesion of the enamel. Annexes A and B are for information only.

This International Standard specifies a method of determining, by successive thermal shock tests, the
behaviour of vitreous and porcelain enamelled cooking utensils and similar articles under sudden
changes of temperature (resistance to thermal shock).

Applies to enamelled walls of roasting devices, grills and baking devices; self-cleaning consists in the capacity first to absorb oil or fat in droplet form, and then to volatilize the greater part of the fat or oil by the sequential processes of distillation, decomposition, and combustion. Is not applicable to pyrolytically cleaning enamels.

This document specifies the general properties of hot dip galvanized coatings and test methods for hot dip galvanized coatings applied by dipping fabricated iron and steel articles (including certain castings) in a zinc melt (containing not more than 2 % of other metals). This document does not apply to the following:
a) sheet, wire and woven or welded mesh products that are continuously hot dip galvanized;
b) tube and pipe that are hot dip galvanized in automatic plants;
c) hot dip galvanized products (e.g. fasteners) for which specific standards exist and which can include additional requirements or requirements which are different from those of this document.
NOTE      Individual product standards can incorporate this document for the galvanized coating by quoting its number, or can incorporate it with modifications specific to the product. Different requirements can also be made for galvanized coatings on products intended to meet specific regulatory requirements.
This document does not apply to after-treatment or additional coating of hot dip galvanized articles.

This document specifies a destructive method for the measurement of the local thickness of metallic and other inorganic coatings by examination of cross-sections with a scanning electron microscope (SEM). The method is applicable for thicknesses up to several millimetres, but for such thick coatings it is usually more practical to use a light microscope (see ISO 1463). The lower thickness limit depends on the achieved measurement uncertainty (see Clause 10).
NOTE       The method can also be used for organic layers when they are neither damaged by the preparation of the cross-section nor by the electron beam during imaging.

This document specifies:
a) the determination of mass gain;
b) the surface inspection of products of zirconium and its alloys when corrosion is tested in water at 360 °C or in steam at or above 400 °C;
c) the performance of tests in steam at 10,3 MPa.
This document is applicable to wrought products, castings, powder metallurgy products and weld metals.
This method has been widely used in the development of new alloys, heat-treating practices and for the evaluation of welding techniques. It is applicable for use in its entirety to the extent specified for a product acceptance test, rather than merely a means of assessing performance in service.

This document specifies four electrographic tests for assessing the porosity of electrodeposited gold and gold alloy coatings for engineering, and decorative and protective purposes.

This document specifies a test method for determining the resistance of vitreous and porcelain enamel coatings to abrasion by rubbing, grinding or other mechanical effects.

Specifies the requirements for the testing apparatus to be used. Includes a general description and figures.

1.1  This document specifies procedures for designing, preparing and using pre-cracked specimens for investigating the susceptibility of metal to stress corrosion cracking (SCC) by means of tests conducted under rising load or rising displacement. Tests conducted under constant load or constant displacement are dealt with in ISO 7539-6.
The term “metal” as used in this document includes alloys.
1.2  Because of the need to confine plasticity at the crack tip, pre-cracked specimens are not suitable for the evaluation of thin products such as sheet or wire and are generally used for thicker products including plate, bar, and forgings. They can also be used for parts joined by welding.
1.3  Pre-cracked specimens can be stressed quantitatively with equipment for application of a monotonically increasing load or displacement at the loading points.
1.4  A particular advantage of pre-cracked specimens is that they allow data to be acquired from which critical defect sizes, above which stress corrosion cracking can occur, can be estimated for components of known geometry subjected to known stresses. They also enable rates of stress corrosion crack propagation to be determined.
1.5  A principal advantage of the test is that it takes account of the potential impact of dynamic straining on the threshold for stress corrosion cracking.
1.6  At sufficiently low loading rates, the threshold stress intensity factor for susceptibility to stress corrosion cracking, KISCC, determined by this method can be less than or equal to that obtained by constant load or displacement methods and can be determined more rapidly.

This document specifies methods for the determination of
—    the presence of colourless chromate conversion coatings,
—    the presence of hexavalent chromium in colourless and coloured coatings on zinc or cadmium or aluminium-zinc (mass fraction of aluminium: 55 %, within a range of 54 % to 56 % mass fraction) and zinc-aluminium (mass fraction of aluminium: 5 %) alloys,
—    the total chromium content per unit area on zinc and cadmium,
—    the mass per unit area of both colourless and coloured coatings,
—    the satisfactory adhesion of chromate conversion coatings, and
—    the quality of chromate coatings.
These methods are applicable to
—    colourless and coloured chromate conversion coatings containing trivalent and hexavalent chromium in varying proportions and produced by either chemical or electrochemical processes, and
—    chromate coatings that are free from any supplementary coatings, such as oil, water or solvent-based polymers or wax.

This document specifies a method for the measurement of the local thickness of metallic coatings, oxide layers, and porcelain or vitreous enamel coatings, by the microscopical examination of cross-sections using an optical microscope.

This document specifies a method for the measurement of metal coating thickness by first forming a step between the surface of the coating and the surface of its substrate and then measuring the step height using a profile recording instrument. It covers the instrumentation characteristics and the procedure appropriate to this specific application of profilometric methods.
The method is applicable to the measurement of thicknesses of metal coatings from 0,01 µm to 1 000 µm on flat surfaces and, if appropriate precautions are taken, on cylindrical surfaces. It is highly suitable for the measurement of minute thicknesses but, for thicknesses of less than 0,01 µm, surface flatness and surface smoothness are very critical and, accordingly, the method is not suitable for use down to the lowest level of measurement usual for electronic stylus instruments. The method is suitable for measuring coating thicknesses when preparing coating thickness reference standards.

This document specifies procedures for the removal of corrosion products formed on metal and alloy corrosion test specimens during their exposure in corrosive environments. For the purpose of this document, the term "metals" refers to pure metals and alloys.
The specified procedures are designed to remove all corrosion products without significant removal of base metal. This allows an accurate determination of the mass loss of the metal, which occurred during exposure to the corrosive environment.
In some cases, these procedures are also applicable to metal coatings, providing the possible effects from the substrate are considered.

This document specifies a method of determining the mass per unit area of hot dip galvanized coatings on ferrous materials.
Since an exact knowledge of the area of the surface is essential, this document is mainly applicable to shapes whose areas are easy to determine. If, with heavy samples, the specifications of Clause 7 cannot be met, then the hot dip galvanized coating mass is determined by another method.

This document gives guidelines for the selection of procedures that can be used in the identification and examination of corrosion pits and in the evaluation of pitting corrosion and pit growth rate.

This document specifies methods for determining corrosion rates with standard specimens of metals in indoor atmospheres with low corrosivity. For this direct method of evaluation corrosivity, different sensitive methods can be applied using standard specimens of the following metals: copper, silver, zinc, steel and lead. The values obtained from the measurements are used as classification criteria for the determination of indoor atmospheric corrosivity.

This document establishes a classification of low corrosivity of indoor atmospheres.
It specifies the reference metals for which a corrosion attack after a defined exposure period is used for determining corrosivity categories of indoor atmospheres of low corrosivity.
It defines corrosivity categories of indoor atmospheres according to corrosion attack on standard specimens.
It indicates important parameters of indoor atmospheres that can serve as a basis for an estimation of indoor corrosivity.
The selection of a method for the determination of corrosion attack, description of standard specimens, exposure conditions and evaluation are given in ISO 11844-2. The measurement of environmental parameters affecting indoor corrosivity is given in ISO 11844-3.

This document specifies procedures for designing, preparing and using reversed U-bend (RUB) test specimens for investigating the susceptibility of the metal to stress corrosion cracking. The term "metal" as used in this document includes alloys.

This document defines terms relating to corrosion that are widely used in modern science and technology. In addition, some definitions are supplemented with short explanations.
NOTE 1  Throughout the document, IUPAC rules for electrode potential signs are applied. The term "metal" is also used to include alloys and other metallic materials.
NOTE 2  Terms and definitions related to the inorganic surface treatment of metals are given in ISO 2080.

This document specifies two low voltage tests for detecting and locating defects that extend to the basis metal in vitreous and porcelain enamel coatings.
Method A (electrical) is applicable to the rapid detection and determination of the general location of defects. Method B (optical), based on colour effects, is applicable to the more precise detection of defects and their exact locations. Both methods are commonly applied to flat surfaces. For more intricate shapes, such as undulated and/or corrugated surfaces, ISO 8289-2 is applicable.
NOTE 1  Selection of the correct test method is critical to distinguish the areas of increased conductivity detected by method B from actual pores that extend to the basis metal, which can be detected by both methods.
NOTE 2  The low voltage test is a non-destructive method of detecting defects and, therefore, is completely different from the high voltage test specified in ISO 2746. The results of the high and low voltage tests are not comparable and will differ.

This document specifies methods for measuring the environmental parameters used to classify the corrosivity of indoor atmospheres on metals and alloys.

This document gives guidelines and recommendations for the general principles of design appropriate to articles to be hot dip galvanized after fabrication (e.g. in accordance with ISO 1461) for the corrosion protection of, for example, articles that have been manufactured in accordance with EN 1090-2.
This document does not apply to hot dip galvanized coatings applied to continuous wire or sheet (e.g. to EN 10346).

This document specifies the quality requirements for apparatus, components, appliances and accessories of glass-lined steel (including semi-crystallized enamel coatings) and glass-lined steel castings used for process plants. It specifies the quality requirements and the tests to be carried out by the manufacturer as well as the actions to be taken to repair defects.
It is also applicable to glass-lined pumps, pump components and fittings.
It does not apply to glass-lined flanged steel pipes or glass-lined flanged steel fittings.
NOTE 1  Provisions for glass-lined flanged steel pipes and glass-lined flanged steel fittings are given in ISO 28721-4.
The test methods specified cover checking the enamel, the dimensional accuracy and the performance of apparatus and components.
This document is applicable to new apparatus and components as well as used items that have been re-enamelled.
It does not contain requirements regarding the chemical or physical properties of vitreous and porcelain enamels.
NOTE 2  Examples of test reports are given in Annex A.

This document specifies a method for using phase-sensitive eddy-current instruments for non-destructive measurements of the thickness of non-magnetic metallic coatings on metallic and non-metallic basis materials such as:
a)    zinc, cadmium, copper, tin or chromium on steel;
b)    copper or silver on composite materials.
The phase-sensitive method can be applied without thickness errors to smaller surface areas and to stronger surface curvatures than the amplitude-sensitive eddy-current method specified in ISO 2360, and is less affected by the magnetic properties of the basis material. However, the phase-sensitive method is more affected by the electrical properties of the coating materials.
In this document, the term "coating" is used for materials such as, for example, paints and varnishes, electroplated coatings, enamel coatings, plastic coatings, claddings and powder coatings.
This method is particularly applicable to measurements of the thickness of metallic coatings. These coatings can be non-magnetic metallic coatings on non-conductive, conductive or magnetic base materials, but also magnetic coatings on non-conductive or conductive base materials.
The measurement of metallic coatings on metallic basis material works only when the product of conductivity and permeability (σ, μ) of one of the materials is at least a factor of two times the product of conductivity and permeability for the other material. Non-ferromagnetic materials have a relative permeability of one.

This document specifies the minimum requirements and the functional characteristics of enamel coatings applied by any process, such as wet dipping, wet flow-coating, wet spraying, wet electrostatic spraying, wet electrodeposition or dry-powder electrostatic spraying, to profiled steel heat exchanger panels in regenerative heat exchangers, before and after packing in baskets.
For very severe service conditions, or to obtain extended operational life, more stringent limits can be agreed between customer and supplier.

This document specifies a low-voltage test method for detecting and locating defects (pores, cracks or pop-offs) that occur in enamel coatings of corrugated and/or undulated profiles and that extend down to the metal base.
The method is based on colour effects (optical method) and is applicable to the precise detection of defects and their exact position. It can be used for non-flat, more profiled shapes such as corrugated or undulated surfaces.
NOTE       The low-voltage test is a non-destructive test for detecting defects extending down to the metal base and is, therefore, completely different in comparison to the high-voltage test in accordance with ISO 2746.

This document specifies the requirements for product quality and product testing of enamelled valves and pressure pipe fittings for untreated and potable water supply.
It does not apply to chemical service glass-enamel and apparatus enamel.

This document gives guidelines for determining the average surface density over a measured area of anodic oxide or of a coating deposited autocatalytically, mechanically, by chemical conversion, by electrodeposition, by hot dip galvanizing and by chemical or physical vapour deposition using gravimetric and other chemical analysis procedures that have attained some degree of national or international standardization.
A variety of procedures are described and include:
—          gravimetric procedures for chemical or electrochemical dissolution of the coating or the substrate to determine the coating surface density;
—          gravimetric procedures for weighing the uncoated substrate and the coated (finished) specimen to determine the coating surface density;
—          analytical procedures that utilize dissolution of the coating for determination of the coating surface density by instrumental chemical analysis methods.
With the exception of the gravimetric method as described in ISO 3892, this document does not give the measurement uncertainties of the methods cited.

This document specifies requirements for electroplated coatings of metallic chromium, with or without undercoats, on ferrous and non-ferrous metals for engineering purposes. The coating designation provides a means of specifying the thickness of chromium appropriate for typical engineering applications.

This document specifies a quantitative method for the measurement of adhesive strength of metallic and other inorganic coatings applied to metallic, polymer and glass substrates.
Typical coatings for which this document applies are metallic coatings such as aluminium, copper, nickel, nickel plus chromium, silver, tin, tin-nickel alloys, zinc, gold as well as other inorganic coatings such as oxides or nitrides, e.g. of aluminium, indium and indium-tin, silicon, niobium, titanium, tungsten, zirconium and others.
This document does not apply to certain hot dip, spray and mechanical coatings, for which other standards may apply, e.g. EN ISO 14916 or EN ISO 4624.
The measurement is valid if the cohesion and adhesion properties of the adhesive are higher than those of the coating subjected to test.

This document specifies a method for the determination of resistance to stress corrosion cracking (SCC) of magnesium alloys intended for use in structural applications (such as magnesium front end, gearbox and clutch housing units, steering column parts, shift actuators, valve covers and housings, brackets and intake manifold blades, electronic devices, power tools and medical equipment). The method allows determination of the resistance to SCC as a function of the chemical composition, the method of manufacture and heat treatment of magnesium alloys.
The document is applicable to cast and wrought magnesium alloys in the form of castings, semi-finished products, parts and weldments and covers the method of sampling, the types of specimens, the loading procedure, the type of environment and the interpretation of results.
The document allows assessment of the relative performance of materials and products in environments containing chlorides or sulphates, provided that the failure mechanism is not changed, but does not qualify a material or product for service application.