ISO 10275-2020 pdf free.Metallic materials – Sheet and strip – Determination of tensile strain hardening exponent.
This document specifies a method for determining the tensile strain hardening exponent n of flat products (sheet and strip) made of metallic materials.
The method is valid only for that part of the stress-strain curve in the plastic range where the curve is continuous and monotonic (see 8.4).
In the case of materials with a serrated stress-strain curve in the work hardening range (materials which show the Portevin-Le Chatelier effect, e.g. AlMg-alloys), the automatic determination (linear regression of the logarithm true stress vs. the logarithm true plastic strain, see 8.2) is used to give reproducible results.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 6892-1, Metallic materials一Tensile testing一Part 1: Method of test at room temperature
ISO 7500-1, Metallic materials一Calibration and verification of static uniaxial testing machines一Part 1:Tension/compression testing machines一Calibration and verification of the force-measuring system
ISO 9513, Metallic materials一Calibration of extensometer systems used in uniaxial testing
ISO 10113, Mtallic materials – Sheet and strip – – Determination of plastic strain ratio
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
一ISO Online browsing platform: available at hts://wwwis.org/obp
一IEC Electropedia: available at http://www.electropedia.org/
4 Symbols and designations
4.1 The symbols and corresponding designations used in determining the tensile strain hardening exponent are given in Table 1.
5 Principle
A test piece is subjected to uniaxial tensile strain at a prescribed constant rate within the region of uniform plastic strain. The tensile strain hardening exponent n is calculated either by considering a portion of the stress-strain curve in the plastic region, or by considering the whole uniform plastic strain region.
6 Test equipment
6.1 Tensile testing machine, verified and calibrated in accordance with ISO 7500-1 and of class 1 or better. The method of gripping the test piece shall conform to the requirements of ISO 6892-1.
6.2 Extensometer, of class 2 or better (class 1 in the event of determination of the plastic strain ratior, see ISO 10113) in accordance with ISO 9513, for measuring changes in the gauge length.
6.3 Dimension-measuring equipment, capable of measuring the width and thickness of the parallel- sided section of the test piece to within the tolerances specified for these dimensions in IS0 6892-1.
7 Test pieces
7.1 Sampling to obtain test pieces shall be in accordance with the requirements of the relevant product standard or, if not specified therein, by agreement. Machining tolerances, tolerances on shape, and the marking shall be as specified in ISO 6892-1.
7.2 In the event of the plastic strain ratio r and the tensile strain hardening exponent n being determined simultaneously, the conditions of ISO 10113 shall apply.
The thickness of the test piece shall be that of the full sheet, unless otherwise specified.
7.4 The surface of the test piece shall not be damaged (by scratches, etc.).
8 Procedure
8.1 In general, the test shall be carried out at ambient temperature, i.e. between 10 °。C and 35 °C. Tests carried out under controlled conditions, where required, shall be made at a temperature of(23+5) °C.
8.2 The test piece shall be mounted in the tensile testing machine (see 6.1) so that the force can be applied axially in accordance with ISO 6892-1.ISO 10275 pdf download.