ISO/TC 164 - Mechanical testing of metals

This document specifies guidelines for testing metallic sheet materials to determine the stress-strain characteristics at high strain rates. This document covers the use of elastic-bar-type systems. This test method covers the strain-rate range above 102 s−1. NOTE This testing method is also applicable to tensile test-piece geometries other than the flat test pieces considered here.

This document applies to force-controlled thermo-mechanical fatigue (TMF) testing. Both forms of control, force or stress, can be applied according to this document. This document describes the equipment, specimen preparation, and presentation of the test results to determine TMF properties.

This document specifies the instrumented indentation method for testing at elevated temperature for determination of hardness and other materials parameters at temperatures above ambient. Elevated temperature testing is defined in this document to be when the test piece and indenter tip are heated above the ambient conditions of the instrument to a controlled and measured temperature; insulating shielding is used to enclose the hot zone to reduce heating effects so that the majority of the instrumented indentation testing machine is at ambient conditions. This document is restricted to test machines that have been traceably calibrated and pass an indirect verification according to ISO 14577-2 when operating at elevated temperature to ensure that any effects on ambient sensors caused by the presence of a hot zone are accounted for. This document covers instrumented indentation testing at elevated temperatures in air, in inert or reducing gaseous environments, or in vacuum. This document provides a method for instrumented indentation testing at elevated temperature with both the indenter tip and test piece actively heated, and with independent feedback control and temperature measurement of both the indenter tip and test piece. This document provides a method for estimation of the uncertainty of the contact temperature. The uncertainty increases as the thermal conductivity of the test piece decreases. It is left to the user to decide if that uncertainty is fit for their purpose. The test method in this document is not applicable to: — instrumented indentation testing where there is no direct measurement of the temperature of the indenter tip body itself; — instrumented indentation testing where above ambient temperatures are obtained by placing the entire instrument in a hot box to achieve iso-thermal heating of the whole system. These systems typically only achieve limited elevated temperature; — instrumented indentation testing with active heating of the test piece but only passive heating of the indenter, e.g. by proximity to the hot test piece and thermal conduction through the indentation contact, hot gas, or any combination.

This document provides specifications for testing miniaturised metallic test pieces where not enough material is available for test pieces according to ISO 6892-1. The guidelines in this document are not intended to replace the requirements of the standard method described in ISO 6892-1. This document refers to conventionally manufactured materials. NOTE 1 Additional information regarding testing of additively manufactured materials are given in ISO/ASTM 52909[5]. NOTE 2 Further information on the performance of miniaturised test pieces in tensile testing and the comparability of respective results is available in References [8] to [14].

This document specifies a method for determining the ability of metallic wire of diameter or characteristic dimension from 0,3 mm to 10 mm to undergo plastic deformation during reverse bend test. The range of applicable diameters or characteristic dimensions is more precisely specified in the relevant product standard.

This document specifies the geometries and proposed finishing procedures of the inner surface of hollow test piece of metallic materials, filled with a high-pressure gaseous medium. The document specifies a tensile testing procedure to evaluate the effect of high-pressure gaseous medium compared to a high-pressure inert gas or air. The document can be used for the screening of metallic materials by evaluating mechanical property changes due to the effects of various test gases, including hydrogen. NOTE Temperature range and pressure range depend on the materials to be tested and test gas to be used.

This document describes how the evaluation of uncertainties in tensile tests can be obtained from tests at room temperature (ISO 6892-1) or elevated temperature (ISO 6892-2). This document reports how it can be applied to tests performed at ambient and elevated temperatures under axial loading conditions with a digital acquisition of force and displacement. NOTE 1 As CWA 15261-2 and UNCERT CoP 07 reports, the tests are assumed to run continuously without interruptions on test pieces that have uniform gauge lengths. NOTE 2 Annex C gives for information an indication of the typical scatter in tensile test results for a variety of materials that have been reported during laboratory inter-comparison exercises.

This document specifies two separate methods of verification of testing machines (direct and indirect) for determining Rockwell hardness in accordance with ISO 6508-1, together with a method for verifying Rockwell hardness indenters. The direct verification method is used to determine whether the main parameters associated with the machine function, such as applied force, depth measurement, and testing cycle timing, fall within specified tolerances. The indirect verification method uses a number of calibrated reference hardness blocks to determine how well the machine can measure a material of known hardness. This document is applicable to stationary and portable hardness testing machines. Attention is drawn to the fact that the use of tungsten carbide composite for ball indenters is considered to be the standard type of Rockwell indenter ball.

This document specifies a method for the calibration of reference blocks to be used for the indirect and daily verification of Rockwell hardness testing machines and indenters, as specified in ISO 6508-2. This document also specifies requirements for Rockwell machines and indenters used for calibrating reference blocks and specifies methods for their calibration and verification. Attention is drawn to the fact that the use of hard metal for ball indenters is considered to be the standard type of Rockwell indenter ball.

This document specifies the method for Rockwell regular and Rockwell superficial hardness tests for scales A, B, C, D, E, F, G, H, K, 15N, 30N, 45N, 15T, 30T, and 45T for metallic materials and is applicable to stationary and portable hardness testing machines. For specific materials and/or products, other specific International Standards apply (e.g. ISO 3738-1 and ISO 4498).

This document specifies the method of instrumented indentation test for evaluation of stress change between reference and target states using indentation force differences. This document primarily applies to measuring the stress change in a specific location and the stress difference between different locations.

This document specifies the Vickers hardness test method for the three different ranges of test force for metallic materials, including hard metals and other cemented carbides (see Table 1), metallic coatings and other inorganic coatings. The Vickers hardness test is specified in this document for lengths of indentation diagonals between 0,020 mm and 1,400 mm. Using this method to determine Vickers hardness from smaller indentations is outside the scope of this document as results would suffer from large uncertainties due to the limitations of optical measurement and imperfections in tip geometry. The Vickers hardness specified in this document is also applicable for metallic and other inorganic coatings including electrodeposited coatings, autocatalytic coatings, sprayed coatings and anodic coatings on aluminium. This document is applicable to measurements normal to the coated surface and to measurements on cross-sections, provided that the characteristics of the coating (smoothness, thickness, etc.) permit accurate readings of the diagonal of the indentation. This document is not applicable for coatings with thickness less than 0,030 mm when testing normal to the coating surface. This standard is not applicable for coatings with thickness less than 0,100 mm when testing a cross-section of the coating. ISO 14577-1 can be used for the determination of hardness from smaller indentations.” A periodic verification method is specified for routine checking of the testing machine in service by the user. For specific materials and/or products, relevant International Standards exist.

This document specifies the Knoop hardness test method for metallic materials for test forces from 0,009 807 N to 19,613 N. This document specifies Knoop hardness tests for length of the long diagonal ≥0,020 mm. Using this method to determine the Knoop hardness from smaller indentations is outside the scope of this document as results would suffer from large uncertainties due to the limitations of optical measurement and imperfections in tip geometry. The Knoop hardness test specified in this document is also applicable for metallic and other inorganic coatings including electrodeposited coatings, autocatalytic coatings, sprayed coatings and anodic coatings on aluminium. This document is applicable to measurements normal to the coated surface and to measurements on cross-sections, provided that the characteristics of the coating (smoothness, thickness, etc.) permit accurate readings of the diagonal of the indentation. This document is not applicable for coatings with thickness less than 0,007 mm when testing normal to the coating surface. This document is not applicable for coatings with thickness less than 0,020 mm when testing a cross-section of the coating. ISO 14577-1 can be used for the determination of hardness from smaller indentations. A periodic verification method is specified for routine checking of the testing machine in service by the user.

This document specifies the methods for: a) uninterrupted creep tests with continuous monitoring of extension; b) interrupted creep tests with periodic measurement of elongation; c) stress rupture tests where normally only the time to fracture is measured; d) a test to verify that a predetermined time can be exceeded under a given force, with the elongation or extension not necessarily being reported. NOTE A creep test can be continued until fracture has occurred or it can be stopped before fracture.

This document specifies a method of instrumented Charpy V-notch pendulum impact testing on metallic materials and the requirements concerning the measurement and recording equipment. With respect to the Charpy pendulum impact test described in ISO 148-1, this test provides further information on the fracture behaviour of the product under impact testing conditions. The results of instrumented Charpy test analyses are not directly transferable to structures or components and shall not be directly used in design calculations or safety assessments. NOTE General information about instrumented impact testing can be found in References [1] to [5].

This document specifies a method for designating test specimen axes in relation to product texture by means of an X-Y-Z orthogonal coordinate system. This document applies equally to unnotched and notched (or precracked) test specimens. This document is intended only for metallic materials with uniform texture that can be unambiguously determined. Test specimen orientation is decided before specimen machining, identified in accordance with the designation system specified in this document, and recorded.

This document specifies a method for determining the ability of metallic wire, of diameter dimension from 0,3 mm to 10,0 mm inclusive, to undergo plastic deformation during reverse torsion. This test is used to detect surface defects, as well as to assess ductility.

This document specifies the method of linear elastic dynamic instrumented indentation test for determination of indentation hardness and indentation modulus of materials showing elastic-plastic behaviour when oscillatory force or displacement is applied to the indenter while the load or displacement is held constant at a prescribed target value or while the indenter is continuously loaded to a prescribed target load or target depth.

This document specifies a method for determining the ear height of metal sheet and strip of nominal thickness from 0,1 mm to 3 mm after deep drawing.

This document establishes verification procedures to determine the accuracy, speed of response, and stability of temperature measurement for materials testing equipment. These procedures are specified for the expected use in fatigue tests on metals where these characteristics are important to the fidelity of tests at high or varying temperature. The principles set out include sufficient provision for both contacting and non-contacting methods of temperature measurement. This document is for the end-to-end verification of registered value compared with “true” specimen temperature at the point of measurement. It cannot be used to specify the correct method or location of measurement. NOTE: The methodologies could be found applicable to test types beyond mechanical fatigue of metals, but that is outside the remit of this document.

This document specifies terms and definitions, symbols and designations, principle, apparatus, test piece, procedure, data processing, evaluation of test result, test report and other contents for the torsion test at high strain rates for metallic materials by using torsional split Hopkinson bar (TSHB).

This document specifies a method for determination of the biaxial stress-strain curve of metallic sheets having a thickness below 3 mm in pure stretch forming without significant friction influence. In comparison with tensile test results, higher strain values can be achieved. NOTE In this document, the term "biaxial stress-strain curve" is used for simplification. In principle, in the test the "biaxial true stress-true strain curve" is determined.

This document applies to stress and/or force-controlled thermo-mechanical fatigue (TMF) testing. Both forms of control, force or stress, can be applied according to this document. This document describes the equipment, specimen preparation, and presentation of the test results in order to determine TMF properties.

This document specifies the conditions for performing torsional, constant-amplitude, nominally elastic stress fatigue tests on metallic specimens without deliberately introducing stress concentrations. The tests are typically carried out at ambient temperature or an elevated temperature in air by applying a pure couple to the specimen about its longitudinal axis. While the form, preparation and testing of specimens of circular cross-section and tubular cross-section are described in this document, component and other specialized types of testing are not included. Similarly, low-cycle torsional fatigue tests carried out under constant-amplitude angular displacement control, which lead to failure in a few thousand cycles, are also excluded.

This document specifies the method for torsion test at room temperature of metallic materials. The tests are conducted at room temperature to determine torsional properties.

This document specifies the method for rotating bar bending fatigue testing of metallic materials. The tests are conducted at room temperature or elevated temperature in air, the specimen being rotated. Fatigue tests on notched specimens are not covered by this document, since the shape and size of notched specimens have not been standardized. However, fatigue test procedures described in this document can be applied to fatigue tests of notched specimens.

This document specifies methods for determining fracture toughness in terms of K, δ, J and R-curves for homogeneous metallic materials subjected to quasistatic loading. Specimens are notched, precracked by fatigue and tested under slowly increasing displacement. The fracture toughness is determined for individual specimens at or after the onset of ductile crack extension or at the onset of ductile crack instability or unstable crack extension. In cases where cracks grow in a stable manner under ductile tearing conditions, a resistance curve describing fracture toughness as a function of crack extension is measured. In some cases in the testing of ferritic materials, unstable crack extension can occur by cleavage or ductile crack initiation and growth, interrupted by cleavage extension. The fracture toughness at crack arrest is not covered by this document. Special testing requirements and analysis procedures are necessary when testing weldments, and these are described in ISO 15653 which is complementary to this document. Statistical variability of the results strongly depends on the fracture type, for instance, fracture toughness associated with cleavage fracture in ferritic steels can show large variation. For applications that require high reliability, a statistical approach can be used to quantify the variability in fracture toughness in the ductile-to-brittle transition region, such as that given in ASTM E1921. However, it is not the purpose of this document to specify the number of tests to be carried out nor how the results of the tests are to be applied or interpreted.

This document specifies the method for measuring the stress-strain curves of sheet metals subject to biaxial tension using a cruciform test piece fabricated from a sheet metal sample. The applicable thickness of the sheet is 0,1 mm or more and 0,08 times or less of the arm width of the cruciform test piece (see Figure 1). The test temperature ranges from 10 °C to 35 °C. The amount of plastic strain applicable to the gauge area of the cruciform test piece depends on the force ratio, slit width of the arms, work hardening exponent (n-value) (see Annex B) and anisotropy of a test material.

This document specifies the conditions for conducting the plane bending fatigue test on an axial machine, constant-amplitude, force or displacement controlled, at room temperature (ideally between 10 °C and 35 °C) on metallic specimens, without deliberately introduced stress concentrations. This document does not include the reversed/partially loading test. The purpose of the test is to provide relevant results, such as the relation between applied stress and number of cycles to failure for a given material condition, expressed by hardness and microstructure, at various stress ratios. Although the shape, preparation and testing of specimens of rectangular and bevelled cross-section are specified, component testing and other specialized forms of testing are not included in this document. Fatigue tests on notched specimens are not covered by this document since the shape and size of notched test pieces have not been specified in any standard so far. Guidelines are given in Annex A. However, the fatigue-test procedures described in this document can be used for testing such notched specimens. It is possible for the results of a fatigue test to be affected by atmospheric conditions. Where controlled conditions are required, ISO 554:1976, 2.1 applies.

This document specifies testing conditions for use when constructing a forming-limit curve (FLC) at ambient temperature and using linear strain paths. The material considered is flat, metallic and of thickness between 0,3 mm and 4 mm. NOTE The limitation in thickness of up to 4 mm is proposed, giving a maximum allowable thickness to the punch diameter ratio.

This document specifies a procedure for developing forming-limit diagrams and forming-limit curves for metal sheets and strips of thicknesses from 0,3 mm to 4 mm.

This document specifies a method for determining the ability of metallic materials to undergo plastic deformation in bending. This document applies to test pieces taken from metallic products, as specified in the relevant product standard. It is not applicable to certain materials or products, for example tubes in full section or welded joints, for which other standards exist.

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 8.7) is used to give reproducible results.

This document specifies methods for high speed compression testing, at room temperature, of porous and cellular metals having a porosity of 50 % or more. The speed range applicable to this test method is 0,1 m/s to 100 m/s (or 1 s−1 to 103 s−1 in terms of the initial strain rate when the specimen height is 100 mm).

This document specifies a method for determining the plastic strain ratio of flat products (sheet and strip) made of metallic materials.

This document specifies the method for tensile testing of metallic materials and defines the mechanical properties which can be determined at room temperature. NOTE Annex A contains further recommendations for computer controlled testing machines.

This document specifies a test method for the determination of brittle crack arrest toughness. It is applicable to ferritic steel base metals exhibiting ductile to brittle transition behaviour. Applicable materials are rolled steel plates. It is intended for materials with a tensile strength of 950 MPa or less and a test piece thickness of 200 mm or less. The range of arrest temperatures is between −196 °C and +100 °C. This document can be applied to flat rolled steel plates but not to flattened steel pipes because the flattening can cause changes in arrest toughness.

This document describes tests for determining the fatigue crack growth rate from the fatigue crack growth threshold stress-intensity factor range, ΔKth, to the onset of rapid, unstable fracture. This document is primarily intended for use in evaluating isotropic metallic materials under predominantly linear-elastic stress conditions and with force applied only perpendicular to the crack plane (mode I stress condition), and with a constant force ratio, R.

ISO/TR 12112:2018 discusses the general principles of multiaxial fatigue testing and the design recommendations for specific classes of multiaxial testing machines and test specimens.

ISO 6892-2:2018 specifies a method of tensile testing of metallic materials at temperatures higher than room temperature.

ISO 6507-4:2018 gives tables of Vickers hardness for use in tests carried out in accordance with ISO 6507‑1.

ISO 7500-1:2018 specifies the calibration and verification of tension/compression testing machines. The verification consists of: - a general inspection of the testing machine, including its accessories for the force application; - a calibration of the force-measuring system of the testing machine; - a confirmation that the performance properties of the testing machine achieve the limits given for a specified class. NOTE This document addresses the static calibration and verification of the force-measuring systems. The calibration values are not necessarily valid for high-speed or dynamic testing applications. Further information regarding dynamic effects is given in the Bibliography. CAUTION Some of the tests specified in this document involve the use of processes which can lead to a hazardous situation.

ISO 26203-1:2018 specifies methods for testing metallic sheet materials to determine the stress-strain characteristics at high strain rates. This document covers the use of elastic-bar-type systems. The strain-rate range between 10−3 and 103 s−1 is considered to be the most relevant to vehicle crash events based on experimental and numerical calculations such as the finite element analysis (FEA) work for crashworthiness. In order to evaluate the crashworthiness of a vehicle with accuracy, reliable stress-strain characterization of metallic materials at strain rates higher than 10−3 s−1 is essential. This test method covers the strain-rate range above 102 s−1. NOTE 1 At strain rates lower than 10−1 s−1, a quasi-static tensile testing machine that is specified in ISO 7500‑1 and ISO 6892‑1 can be applied. NOTE 2 This testing method is also applicable to tensile test-piece geometries other than the flat test pieces considered here.

ISO 6507-2:2018 specifies a method of verification and calibration of testing machines and diagonal measuring system for determining Vickers hardness in accordance with ISO 6507‑1. A direct method of verification and calibration is specified for the testing machine, indenter and the diagonal length measuring system. An indirect verification method using reference blocks is specified for the overall checking of the machine. If a testing machine is also to be used for other methods of hardness testing, it shall be verified independently for each method. ISO 6507-2:2018 is also applicable to portable hardness testing machines but not applicable to hardness testing machines based on different measurement principles, e.g. ultrasonic impedance method.

ISO 6507-3:2018 specifies a method for the calibration of reference blocks to be used for the indirect verification of Vickers hardness testing machines, as specified in ISO 6507‑2. The method is applicable only for indentations with diagonals ≥0,020 mm.

ISO 15653:2018 specifies methods for determining fracture toughness in terms of stress intensity factor (K), crack tip opening displacement or CTOD (δ) and experimental equivalent of the J-integral for welds in metallic materials (J). ISO 15653:2018 complements ISO 12135, which covers all aspects of fracture toughness testing of parent metal and which needs to be used in conjunction with this document. This document describes methods for determining point values of fracture toughness. It should not be considered a way of obtaining a valid R-curve (resistance-to-crack-extension curve). However, the specimen preparation methods described in this document could be usefully employed when determining R-curves for welds. The methods use fatigue precracked specimens which have been notched, after welding, in a specific target area in the weld. Methods are described to evaluate the suitability of a weld for notch placement within the target area, which is either within the weld metal or within the weld heat-affected zone (HAZ), and then, where appropriate, to evaluate the effectiveness of the fatigue crack in sampling these areas.

ISO 4545-3:2017 specifies the method for the calibration of reference blocks to be used for the indirect verification of Knoop hardness testing machines as specified in ISO 4545‑2. The method is applicable only for indentations with long diagonals ≥0,020 mm.

ISO 4545-2:2017 specifies the method of verification and calibration of testing machines for determining Knoop hardness for metallic materials in accordance with ISO 4545‑1. A direct method of verification and calibration is specified for the testing machine, indenter, and the diagonal length measuring system. An indirect verification method using reference blocks is specified for the overall checking of the machine. If a testing machine is also to be used for other methods of hardness testing, it will be verified independently for each method.

ISO 4545-4:2017 gives a table for the calculation of Knoop hardness values for use in tests carried out in accordance with ISO 4545‑1.

ISO 6506-2:2017 specifies methods of direct and indirect verification of testing machines used for determining Brinell hardness in accordance with ISO 6506‑1 and also specifies when these two types of verification have to be performed. The direct verification involves checking that individual machine performance parameters fall within specified limits whereas the indirect verification utilizes hardness measurements of reference blocks, calibrated in accordance with ISO 6506‑3, to check the machine's overall performance. If a testing machine is also to be used for other methods of hardness testing, it has to be verified independently for each method. ISO 6506-2:2017 is applicable to both fixed location and portable hardness testing machines. For machines that are incapable of satisfying the specified force-time profile, the direct verification of force and testing cycle can be modified by the use of Annex B.