BS EN IEC 60404-12:2023 Magnetic materials. Methods of test for the assessment of the thermal endurance of surface insulation coatings on electrical steel strip and sheet
1 Scope
This part of IEC 60404 is applicable to surface insulation coatings on electrical steel strip and sheet
classified in IEC 60404‑1‑1.
This document defines the general principles and technical details of the tests for
the assessment of the thermal endurance of surface insulation coatings on electrical
steel strip and sheet.
The assessment is made by evaluating the change of a specified property of the surface
insulation coating due to a heat treatment at a specified temperature up to 850 °C
for a specified duration time up to 2 500 h. The specified property is measured at
an ambient temperature of (23 ± 5) °C both without heat treatment and after heat treatment.
This document is applicable to the following properties of surface insulation coatings:
— adhesion;
— surface insulation resistance;
— stacking factor.
This document is not applicable to other properties of surface insulation coatings,
e.g. welding properties, or to other effects, e.g. discoloration and off-gassing,
which can be caused by exposure to elevated temperatures.
NOTE Some of the tests take a very long time to perform and therefore they are often not
appropriate for acceptance tests of material supplied on a specific order.
BS EN IEC 60404-12:2023 Referenced Document
IEC 60404-1-1 Magnetic materials - Part 1-1: Classification - Surface insulations of electrical steel sheet, strip and laminations
ISO 1519 Paints and varnishes - Bend test (cylindrical mandrel)
BS EN IEC 60404-12:2023 history
2023BS EN IEC 60404-12:2023 Magnetic materials. Methods of test for the assessment of the thermal endurance of surface insulation coatings on electrical steel strip and sheet