ISO 6370-1 Vitreous and Porcelain Enamels - Determination of Resistance to Wear - Part 1: Abrasion Tester

The “ISO 6370-1 Vitreous and porcelain enamels - Determination of resistance to abrasion - Part 1: Abrasion tester” standard, developed by the International Organization for Standardization (ISO), describes the requirements for the test apparatus to be used in determining the abrasion resistance of vitreous and porcelain enamel coatings.

The abrasion test apparatus mainly consists of the following parts (the figure given in the standard shows the arrangement of samples and reference glass plates in the apparatus):

• Driven oscillating table: An oscillating table made of steel or light metal, approximately 10 mm thick. It is placed horizontally on an eccentric drive so that during testing each point of the oscillating table describes a horizontal circle with a diameter of 22 mm plus/minus 1 mm. The oscillating table should be large enough to test at least three specimens and to clamp three reference plates onto it by means of retaining rings. Eccentric drive 300 min^-1 plus/minus 3 min^-1 It will operate at the rotational frequency and will be equipped with a device to control this frequency.
• Retaining rings: A minimum of six retaining rings are required for the test apparatus as shown in the figure. The retaining ring shall be made of steel, cast iron or light metal lined with rubber. The opening is used for the introduction of the abrasive load and shall be capable of being closed with a rubber stopper.
• Sealing rings: At least six sealing rings with an internal diameter of 87 mm plus/minus 0,5 mm, a width of 10 mm plus/minus 2 mm and a thickness of 2 mm plus/minus 0,5 mm, made of a non-rigid elastic material (e.g. rubber), are required in the test apparatus.
• Clamping devices: These must press the lower edge of the retaining ring against the sealing ring that holds the sample or reference glass plate on the oscillating table. It must be possible to quickly loosen the clamping devices so that samples and reference glass plates can be easily changed.

For the purposes of this standard, the following terms and definitions apply:

• Vitreous enamel (porcelain enamel) refers to an essentially glassy or vitreous, inorganic coating bonded to a metal by fusion at a temperature above 500 degrees. This coating can be applied for protective, functional or decorative purposes. Such enamels are produced by applying powdered inorganic glass, dry or suspended in water, to a metal surface and then bonding it by fusion. The fused coating is applied over a temperature range of 20 degrees to 100 degrees to a temperature of 150 × 10⁻⁷ /K with 450 × 10⁻⁷ /K shows a cubic thermal expansion, the actual value varies depending on the type of substrate and the field of application.
• Enameled heavy gauge steel panel refers to cold rolled steel panel that is first shaped and then enameled individually or in groups. Generally, the thickness of steel substrate for enameled heavy gauge steel panels is greater than 0,75mm.
• Enameled light gauge steel panel refers to the panel made by cutting porcelain or vitreous enamel top surface material produced in the enameled state in the continuous coil coating line and laminating it onto a suitable core material or sandwich that provides its shape and strength. Generally, the thickness of the top surface steel for enameled light gauge steel panels is 0,30mm to 0,75mm.

In short, vitreous and porcelain enamels are glassy or vitreous inorganic silica coatings bonded to a metallic substrate by fusion at a temperature of at least 480 degrees. Vitreous and porcelain enameling is the process of coating a metal surface with one or more fusion-bonded coatings of vitreous, inorganic materials.

In general, the ability of vitreous and porcelain enamels to resist surface abrasions encountered in daily use is determined by abrading the glazed surface with a wet abrasive medium consisting of 1-5 mm diameter steel balls, aluminum oxide abrasive powder and distilled water, or with a dry abrasive medium consisting of porcelain cylinders and aluminum oxide abrasive powder.

Among the numerous tests, measurements, analyses and evaluation studies carried out for businesses in various sectors, our organization also provides testing services defined in the “ISO 6370-1 Vitreous and porcelain enamels - Determination of resistance to abrasion - Part 1: Abrasion tester” standard with its trained and expert staff and advanced technological equipment.