ISO/TC 164/SC 2 - Ductility testing

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 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 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.

ISO 16630 describes a method of determining the hole expansion ratio in metallic sheets and strips with a thickness range of 1,2 mm to 6,0 mm inclusive and a width of at least 90 mm. NOTE This test is normally applicable to sheet metal and is used to assess the suitability of the product for forming flanges.

ISO 15363:2017 specifies the ring hydraulic pressure test for metallic tubes. It is generally applied to tubes with an outside diameter greater than 120 mm and outside diameter to thickness ratio of not less than 20. The objective of this test is to ascertain the value of the hoop stress required to produce a specified total circumferential (hoop) strain.

ISO 24213:2017 specifies a method for evaluating the amount of springback of sheets of metallic materials known to exhibit large amounts of springback subjected to plane-strain stretch bending, which is a typical deformation mode generated in press-formed panels. By using this method, the amount of springback under stretch bending is evaluated accurately and quantitatively.

ISO 9649:2016 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.

ISO 11531:2015 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.

ISO 20482:2013 specifies a standard test method for determining the ability of metallic sheets and strips having a thickness from 0,1 mm up to 2 mm and a width of 90 mm or greater to undergo plastic deformation in stretch forming. For materials that are thicker and when only narrower strips are available, tools of specified dimensions are provided, in which case subscripts are used, as shown in Table 1.

ISO 8496:2013 specifies a method for a ring tensile test of tubes to reveal surface and internal defects by subjecting the test piece to strain until fracture occurs. This test may also be used to assess the ductility of tubes. The ring tensile test is applicable to tubes having an outside diameter exceeding 150 mm and a wall thickness no greater than 40 mm. The inside diameter shall be greater than 100 mm.

ISO 8492:2013 specifies a method for determining the ability of metallic tubes of circular cross-section to undergo plastic deformation by flattening. It may also be used to reveal the defects in the tubes. ISO 8492:2013 is applicable to tubes having an outside diameter no greater than 600 mm and a thickness no greater than 15 % of the outside diameter. The range of the outside diameter or thickness, for which this International Standard is applicable, may be more exactly specified in the relevant product standard.

ISO 8494:2013 specifies a method for determining the ability of metallic tubes of circular cross-section to undergo plastic deformation during flange formation. ISO 8494:2013 is intended for tubes having an outside diameter no greater than 150 mm and a wall thickness no greater than 10 mm, although the range of diameters or wall thickness for which ISO 8494:2013 is applicable may be more exactly specified in the relevant product standard.

ISO 8495:2013 specifies a method for a ring-expanding test on tubes, that is used to reveal defects both on the surfaces and within the tube wall by expanding the test piece using a conical mandrel until fracture occurs. It may be also used to assess the ability of tubes to undergo plastic deformation. The ring-expanding test is applicable to tubes having an outside diameter from 18 mm up to and including 150 mm and a wall thickness from 2 mm up to and including 16 mm.

ISO 7802:2013 specifies a method for determining the ability of metallic wire of diameter or thickness 0,1 mm to 10 mm inclusive, to undergo plastic deformation during wrapping.

ISO 20032:2013 specifies a method for evaluating the tensile properties of metallic superplastic materials which exhibit what is called "Fine-Grained Superplasticity", without significant work-hardening or dynamic microstructure evolution, by means of a tensile test at constant cross-head velocity, for flat-form test pieces, without an extensometer attached.

This International Standard specifies a method for determining the ability of metallic wire of diameter or characteristic dimension from 0,1 mm to 14 mm to undergo plastic deformation during simple torsion in one direction.

ISO 13314:2011 specifies a test method for compressive properties of porous and cellular metals with a porosity of 50 % or more. Compressive tests can be carried out at ambient temperature under quasi-static strain rate conditions.

Specifies the method for determining the ability of sheet and strip to undergo plastic deformation in reverse bending. Can be applied to aluminium and its alloys only after previous agreement. The reverse bend test consists of repeated bending through 90 , in opposite directions, of a rectangular test piece held at one end, each bend being over a cylindrical support of specified radius.

Specifies the method for determining the ability of wire of diameter or thickness 0,3 to 10 mm inclusive to undergo plastic deformation during reverse bending. The range of diameters of thicknesses for which ISO 7801 is applicable may be more exactly specified in the relevant product standard. The test consists of repeated bending, through 90 in opposite directions, of a test piece held at one end, each bend being over a cylindrical support of a specified radius.

ISO 11531:2015 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.

ISO 7438:2016 specifies a method for determining the ability of metallic materials to undergo plastic deformation in bending. ISO 7438:2016 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.

ISO 18338:2015 specifies the method for torsion test at room temperature of metallic materials. The tests are conducted at room temperature to determine torsional properties.

ISO 16842:2014 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 shall be 0,1 mm or more and 0,08 times or less of the arm width of the cruciform test piece. The test temperature shall range 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), and anisotropy of a test material.

ISO 16808:2014 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.

ISO 17340:2014 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).

ISO 16630:2009 describes a method of determining the hole expansion ratio in metallic sheets and strips with a thickness range of 1,2 mm to 6,0 mm inclusive and a width of at least 90 mm. This test is normally applicable to sheet metal and is used to assess the suitability of the product for forming flanges.

ISO 12004-1:2008 provides guidelines for developing forming-limit diagrams and forming-limit curves for metal sheets and strips of thicknesses from 0,3 mm to 4 mm.

ISO 12004-2:2008 specifies the testing conditions to be used 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.

ISO 24213:2008 specifies a method for evaluating the amount of springback of sheets of metallic materials known to exhibit large amounts of springback subjected to plane-strain stretch bending, which is a typical deformation mode generated in press-formed panels. By using this method, the amount of springback under stretch bending is evaluated accurately and quantitatively.

ISO 10275:2007 specifies a method for determining the tensile strain hardening exponent 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.

ISO 20032:2006 specifies a method for evaluating the tensile properties of metallic superplastic materials which exhibit fine-grained superplasticity, without significant work-hardening or dynamic microstructure evolution, by means of a tensile test at constant cross-head velocity, for flat-form test pieces, without an extensometer attached.

ISO 10113:2006 specifies a method for determining the plastic strain ratio of flat products (sheet and strip) made of metallic materials.

ISO 7438:2005 specifies a method for determining the ability of metallic materials to undergo plastic deformation in bending. ISO 7438:2005 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.

ISO 7800:2003 specifies a method for determining the ability of metallic wire of diameter or characteristic dimension 0,1 mm to 10 mm inclusive to undergo plastic deformation during simple torsion in one direction.

ISO 20482:2003 specifies a standard test method for determining the ability of metallic sheets and strips having a thickness from 0,1 mm up to 2 mm and a width of 90 mm or greater to undergo plastic deformation in stretch forming.

ISO/TS 16630:2003 describes a method of determining the hole expansion ratio in metallic sheets and strips with a thickness range of 1,2 mm to 6 mm inclusive and a width of at least 90 mm.

Provides guidelines for developing forming-limit diagrams and forming-limit curves for metal sheets and strips of nominal thicknesses from 0,2 mm to 3 mm.