ASTM A719-14(R2019) pdf free download

ASTM A719-14(R2019) pdf free download.Standard Test Method for Lamination Factor of Magnetic Materials
1. Scope
1.1 This test method covers measurement of the lamination factor (Note 1) of a specimen composed of strips cut from magnetic material. N OTE 1—Lamination factor is also termed space factor or stacking factor. 1.2 This test method shall be used in conjunction with Practice A34/A34M. 1.3 The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard. Within this test method, SI units are shown in brackets. 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 test method. 1.4 This standard does not purport to address the safety concerns associated with its use. It is the responsibility ofthe user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Summary of Test Method
3.1 The laminated test specimen is subjected to pressure in a compression device and the resulting volume is then deter- mined from the measured specimen height, width, and length. An equivalent solid volume is calculated from the specimen mass and the true density ofthe specimen material. The ratio of the calculated (equivalent solid) volume to the measured volume is the lamination factor.
4. Significance and Use
4.1 Lamination factor, S, indicates the deficiency of effec- tive steel volume which is due to the presence of oxides, roughness, insulating coatings, and other conditions affecting the steel surface. 4.2 The term Lamination Factor, S, pertains strictly to the determination of the proportion of material as defined by precise sampling and procedures of this test method. Alterna- tive usage of the term Lamination Factor has evolved to include sampling and procedures outside of the context of this test method. Consideration of alternative sampling and proce- dures should not be included within the scope of this test method.
5. Apparatus
5.1 Testing Machine—A compression testing machine or other compression device capable of exerting the specified pressure. 5.2 Metal Plates—Two flat, smooth, rigid metal plates with square edges and ends are required. They shall be of sufficient stiffness to distribute the pressure uniformly over the surface of the sample. Each plate shall be 8.46 in. [215 mm] long and have a minimum width of 1.97 in. [50 mm] so that the area of strips under pressure when testing 1.18-in. [30-mm] wide specimens will be 10 in. 2 [6450 mm 2 ]. 5.2.1 Extensions can be added to the plates to allow the use ofmicrometers or outside calipers instead ofinside calipers for determining plate separation. Precautions must be taken to ensure that, within the limits of accuracy of the measurements, no significant deflection ofthese extensions result from the test pressure. 5.3 Length-Measuring Tools—Calipers or other devices of adequate accuracy for measurement of plate separation.
6. Sampling
6.1 Test strips shall be selected as representative of the surface condition. Core loss test specimens (Epstein test specimens) are normally used for this purpose. 6.2 In routine testing, where the core loss specimens are too small to conform to the minimum number ofstrips requirement ofTable 1, sufficient specimens may be combined to provide an adequate test specimen. The combined specimens must be of the same thickness and material, have similar surfaces, and be representative of the surface condition of the test lot. 6.3 When a referee test becomes necessary, the test speci- men must be composed of strips taken from one lot of steel. It must be representative of the surface condition, thickness, and other variables. The shearing burrs should be removed and the strips wiped free of loose particles.