Mecánica de materiales (probetas)

Designation: E 8M – 04 METRIC

Standard Test Methods for

Tension Testing of Metallic Materials [Metric]1
This standard is issued under the fixed designation E 8M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon(e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense.

1. Scope* 1.1 These test methods cover the tension testing of metallic materials in any form at room temperature, specifically, the methods of determination of yield strength, yield point elongation, tensile strength, elongation, andreduction of area.
NOTE 1—These test methods are the metric companion of Test Methods E 8. Committee E-28 was granted an exception in 1997 by the Committee on Standards to maintain E8 and E8M as separate companion standards rather than combining standards as recommended by the Form and Style manual. NOTE 2—These metric test methods are essentially the same as those in Test Methods E 8, and arecompatible in technical content except that gage lengths are required to be 5D for most round specimens rather than 4D as specified in Test Methods E 8. Test specimens made from powder metallurgy (P/M) materials are exempt from this requirement by industrywide agreement to keep the pressing of the material to a specific projected area and density. NOTE 3—Exceptions to the provisions of these test methodsmay need to be made in individual specifications or test methods for a particular material. For examples, see Test Methods and Definitions A 370 and Test Methods B 557M. NOTE 4—Room temperature shall be considered to be 10 to 38°C unless otherwise specified.

A 356/A356M Specification for Steel Castings, Carbon, Low Alloy, and Stainless Steel, Heavy-Walled for Steam Turbines A 370 Test Methods andDefinitions for Mechanical Testing of Steel Products B 557M Test Methods of Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products [Metric] E 4 Practices for Force Verification of Testing Machines E 6 Terminology Relating to Methods of Mechanical Testing E 8 Test Methods for Tension Testing of Metallic Materials E 29 Practice for Using Significant Digits in Test Data to DetermineConformance with Specifications E 83 Practice for Verification and Classification of Extensometers E 345 Test Methods of Tension Testing of Metallic Foil E 691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method E 1012 Practice for Verification of Specimen Alignment Under Tensile Loading 3. Terminology 3.1 Definitions—The definitions of terms relating to tensiontesting appearing in Terminology E 6 shall be considered as applying to the terms used in these test methods of tension testing. Additional terms being defined are as follows: 3.1.1 discontinuous yielding—in a uniaxial test, a hesitation or fluctuation of force observed at the onset of plastic deformation, due to localized yielding. (The stress-strain curve need not appear to be discontinuous.) 3.1.2lower yield strength, LYS [FL−2]—in a uniaxial test, the minimum stress recorded during discontinuous yielding, ignoring transient effects. 3.1.3 upper yield strength, UYS [FL−2]—in a uniaxial test, the first stress maximum (stress at first zero slope) associated with discontinuous yielding. 3.1.4 yield point elongation, YPE—in a uniaxial test, the strain (expressed in percent) separating thestress-strain curve’s first point of zero slope from the point of transition from

1.2 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 2.1 ASTM...