1. Scope

1.1 This test method covers tests for the magnetic properties of basic flat-rolled magnetic materials at power frequencies (25 to 400 Hz) using a 25-cm Epstein test frame and the 25-cm double-lap-jointed core. It covers the determination of core loss, rms exciting power, rms and peak exciting current, and several types of ac permeability and related properties of flat-rolled magnetic materials under ac magnetization.

1.2 This test method shall be used in conjunction with Practice A 34/A 34M.

1.3 This test method provides a test for core loss and exciting current at moderate and high magnetic flux densities up to 15 kG [1.5 T] on nonoriented electrical steels and up to 18 kG [1.8 T] on grain-oriented electrical steels.

1.4 The frequency range of this test method is normally that of the commercial power frequencies 50 to 60 Hz. With proper instrumentation, it is also acceptable for measurements at other frequencies from 25 to 400 Hz.

1.5 This test method also provides procedures for calculating ac impedance permeability from measured values of rms exciting current and for ac peak permeability from measured peak values of total exciting currents at magnetic field strengths up to about 150 Oe [12000 A/m].

1.6 Explanation of symbols and abbreviated definitions appear in the text of this test method. The official symbols and definitions are listed in Terminology A 340.

1.7 The values and equations stated in either customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard. Within this standard, SI units are shown in brackets except in the sections concerning calculations where there are separate sections for the respective unit systems. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this standard.

1.8 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

A34/A34M Practice for Sampling and Procurement Testing of Magnetic Materials

A340 Terminology of Symbols and Definitions Relating to Magnetic Testing

A677 Specification for Nonoriented Electrical Steel Fully Processed Types

A683 Specification for Nonoriented Electrical Steel, Semiprocessed Types

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

A889/A889M Test Method for Alternating-Current Magnetic Properties of Materials at Low Magnetic Flux Density Using the Voltmeter-Ammeter-Wattmeter-Varmeter Method and 25-cm Epstein Frame

E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods

E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

E1338 Guide for Identification of Metals and Alloys in Computerized Material Property Databases

Keywords

alternating-current; ammeter; core loss; customary units; Epstein; exciting power; magnetic; magnetic flux density; magnetic material; magnetic test; permeability; power frequency; voltmeter; wattmeter; A-C (alternating-current) magnetic properties; Alternating-current permeability; Commercial power frequencies; Core loss--alternating-current; Current measurement--alternating-current; Electrical steel (non-oriented); Electrical steel (oriented); Epstein test frame; Exciting current--alternating-current; Nonoriented electrical steel; Oriented electrical steel; Peak exciting current--alternating-current magnetic properties; Wattmeter-ammeter-voltmeter method--magnetic properties;

ICS Code

ICS Number Code 17.220.20 (Measurement of electrical and magnetic quantities)

DOI: 10.1520/A0343_A0343M-03

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