Significance and Use

This classification establishes categories of insulating coatings based on their chemical nature, relative insulating ability, and typical applications. These categories describe general physical and chemical characteristics of the coatings that are useful in making broad estimates of their insulating ability and suitability for various applications.

FIG. 1 Apparatus of Surface Insulation Resistivity Measurement for Franklin Test

FIG. 2 Diagram of Connections for Contacts and Resistors for Franklin Test

1. Scope

1.1 This document classifies insulating coatings for electrical steels according to their composition, relative insulating ability, and functionality. The purpose of this classification is to assist users of insulating coatings by providing general information about the chemical nature and use of the coatings, as well as to provide important data concerning limits to their use, that is, relative insulating ability, punchability, temperature stability, weldability, and fabricability. Specific surface insulation resistivity values for each coating are not included in this classification. The user is referred to the flat-rolled electrical steel specifications noted in 1.2 should more detailed information concerning surface insulation resistivity values be required.

1.2 This classification is to be used in conjunction with the various specifications for flat-rolled electrical steels under the jurisdiction of Committee A06, including Specifications A 345, A 677, A 683, A 726, A 840, and A 876 . However, in those instances in which the coating descriptions and characteristics differ between this classification and any of the specifications, this classification shall supersede the specification.

1.3 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units which are provided for information only and are not considered standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

A345 Specification for Flat-Rolled Electrical Steels for Magnetic Applications

A677 Specification for Nonoriented Electrical Steel Fully Processed Types

A683 Specification for Nonoriented Electrical Steel, Semiprocessed Types

A717/A717M Test Method for Surface Insulation Resistivity of Single-Strip Specimens

A726 Specification for Cold-Rolled Magnetic Lamination Quality Steel, Semiprocessed Types

A840 Specification for Fully Processed Magnetic Lamination Steel

A876 Specification for Flat-Rolled, Grain-Oriented, Silicon-Iron, Electrical Steel, Fully Processed Types

A937/A937M Test Method for Determining Interlaminar Resistance of Insulating Coatings Using Two Adjacent Test Surfaces

Keywords

coating; coreplate; Franklin test; insulation; insulating coating; interlaminar resistance; steel; surface insulation resistivity ; Two Surface test; varnish; Classification (standards)--electrical devices/applications; Classification (standards)--insulation; Composition analysis--metals/alloys; Electrical steel; Insulating coating systems; Relative insulating ability;

ICS Code

ICS Number Code 01.040.25 (Manufacturing engineering (Vocabularies)); 25.220.01 (Surface treatment and coating in general)

DOI: 10.1520/A0976-03R08

ASTM International is a member of CrossRef.

ASTM A976