ISO 13807:2022

Overview

ISO 13807:2022 specifies a laboratory test method to determine the crack formation temperature of vitreous and porcelain enamels used in the chemical industry. The method subjects enamelled steel specimens to a controlled thermal shock - heating in an oven followed by immediate quenching with cold water - and identifies the temperature at which the first enamel cracks or chipping appear. The measured value is a comparative parameter for enamel formulations and does not directly represent the behavior of finished components (see Annex A).

Key topics and technical requirements

• Scope and purpose: Test for thermal shock resistance of enamel coatings on steel to determine crack formation temperature for comparing enamel quality.
• Definitions:
  • Crack formation temperature: thermal shock temperature at which the first damage (cracks/chipping) occurs.
  • Thermal shock temperature: specimen temperature immediately before quenching.
• Specimens:
  • Typical specimen: square steel plate enamelled on one side (edge length 150 mm, thickness ≥ 10 mm) or 10MnTi3 low-alloy enamelling steel with specified nominal composition.
  • Finished enamel coating thickness: overall 1.1 mm to 1.4 mm (measured per ISO 2178).
  • Two specimens are used per determination.
• Apparatus:
  • Drying oven capable of ≥ 300 °C.
  • Low-form beaker (2 000 ml, ISO 3819 compliant) and a spray gun for electrostatically charged talcum powder to reveal fine cracks.
• Procedure summary:
  • Heat specimen to the chosen thermal shock temperature in the oven (about 20 °C below expected crack temperature if known).
  • Remove specimen and quench by pouring 2 L of water at 10 °C–30 °C onto the enamelled surface within 3 s of opening the oven.
  • Dry, visually inspect and spray with charged talcum powder to detect cracks.
  • If no damage, repeat the test at increments of +10 °C; average values within 10 °C are reported.
• Preconditioning: Controlled cooling after final firing-heat to 600 °C for ≥ 20 min then cool to 250 °C at ≤ 1 °C/min to reduce residual stresses.
• Reporting: Include enamel type, coating thickness, material code, individual crack temperatures (°C), mean value, and deviations from the procedure.

Applications and users

• Who uses it: Enamel manufacturers, coating labs, quality control engineers, product developers and procurement teams in the chemical process industry.
• Practical applications:
  • Compare thermal shock resistance of different enamel formulations.
  • Provide a repeatable lab parameter for R&D and QC of vitreous/porcelain enamels.
  • Support material selection for equipment where enamel cracking under rapid cooling is a concern.
• Limitations: The test parameter is for comparing enamels under controlled lab conditions; it should not be used alone to predict finished-product resistance in service (see informative Annex A).

Related standards

• ISO 2178 - Coating thickness measurement (magnetic method)
• ISO 2746 - High voltage test for enamels
• ISO 3819 - Laboratory glassware - Beakers
• ISO 19496-1 - Enamel terminology

Keywords: ISO 13807:2022, thermal shock testing, crack formation temperature, vitreous enamel, porcelain enamel, enamelled steel, chemical industry, enamel testing.