ISO/TC 44/SC 6/WG 3 - Quality management and testing

This document specifies the geometries and dimensions of projections for embossed projection welding. Tools to make the projections are also included in Annex B. The projections are used on hot-rolled, cold-rolled, uncoated and coated steels, stainless steels and nickel alloys for conventional welding quality up to 3 mm thickness, as single projections, in multiples or as a group of multiples. Any solid projections are not included in this document.

This document specifies requirements for resistance spot welding in the fabrication of assemblies of aluminium sheet, extrusions (both work- and age-hardening alloys) and/or cast material comprising two or three thicknesses of metal, where the maximum single (sheet) thickness of components to be welded is within the range 0,6 mm to 6 mm. This document is applicable to the welding of sheets or plates of dissimilar thickness where the thickness ratio is less than or equal to 3:1. It applies to the welding of three thicknesses where the total thickness is less than or equal to 9 mm. Welding with the following types of machines is within the scope of this document: — pedestal welding machines; — gun welders; — automatic welding equipment where the components are fed by robots or automatic feeding equipment; — multi-welders; — robotic welders. Information on appropriate welding equipment is given in Annex A and on spot welding conditions in Annex B. The latter are for guidance only and can require modification depending on service conditions of the fabrication, type of welding equipment, characteristics of the secondary circuit, electrode material and geometry. The welding of coated material, e.g. zinc-coated or anodized material, is outside the scope of this document.

This document specifies test specimens and procedures for performing constant load amplitude fatigue tests on multi-spot-welded and multi-axial specimens in the thickness range from 0,5 mm to 5 mm at room temperature and a relative humidity of maximum 80 %. The applicability of this document to larger thicknesses can be limited by mechanical properties such as yield strength and formability of the specimen material. The thickness range for advanced high strength steels (AHSS) is generally below 3,0 mm. Greater thicknesses apply for aluminium alloys, for example. Depending on the specimen used, it is possible from the results to evaluate the fatigue behaviour of: — spot welds subjected to defined uniform load distribution; — spot welds subjected to defined non-uniform load distribution; — spot welds subjected to different defined combinations of shear-, peel- and normal-tension loads; and — the tested specimen. Multi-spot specimens with which the different load distributions can be realized are the following: a) defined uniform load distribution: H-specimens for shear- and peel-loading, (welds subjected to uniform shear or peel loading transverse to the joint line); single- and double-hat specimens subjected to four-point bending (spot welds subjected to uniform shear load in the direction of the row of welds); double-disc specimen under torsion (spot welds subjected to uniform shear load); double-disc specimen under tensile load (spot welds subjected to uniform peel load); double-disc specimen under combined torsion and tensile loading; flat multi-spot specimens using defined grips; b) defined non-uniform load distribution: H-specimens with modified grips; modified H-specimens with standard grips; modified H-specimens with modified grips; flat multi-spot specimens with modified grips; modified multi-spot flat specimens with standard grips; modified multi-spot flat specimens with modified grips; c) defined combinations of shear-, peel- and normal-tension loads: the KS-2 specimen; the double disc specimen; d) spot welds subjected to undefined non-uniform load distribution — single-hat, double-hat and similar closed hollow sections under torsion, 3-point bending and/or internal pressure. The specimens and tests referred to under c) above are not dealt with further in this document, because the results obtained with these specimens are specific to the components as tested and may not be generalized or used for deriving data pertaining to the load-carrying behaviour of the welds. Results obtained with such tests are suitable for comparing the mechanical properties of the tested components with those of similar components tested in the same manner. These tests are, however, not suitable for evaluating or comparing the load-carrying properties of the welds. The test results of the fatigue tests obtained with component like specimens are suitable for deriving criteria for the selection of materials and thickness combinations for structures and components subjected to cyclic loading. This statement is especially relevant for results obtained with specimens with boundary conditions, i.e. a local stiffness similar to that of the structure in question. The results of a fatigue test are suitable for direct application to design only when the loading conditions in service and the stiffness of the design in the joint area are identical. NOTE Specimens are modified to take into consideration constraints or specific demands posed by design, e.g. smaller than standard overlap, smaller or larger than standard nugget diameter, and specific load distribution, thus enhancing the value of the test results for the design engineer.

This document gives an overview of ISO documents for resistance welding. It covers the following processes: — resistance spot welding; — projection welding; — seam welding; — flash welding; — upset (resistance butt) welding.

ISO 14271:2017 specifies the procedures for the hardness testing of etched cross-sections of resistance spot, projection, and seam welds. The aim of the hardness tests is to determine the Vickers hardness, in the low-force or microhardness range, of the weld nugget, the heat affected zone, and parent material in ferrous or non-ferrous metals for welds made in sheets of thickness 0,5 mm to 6 mm.

ISO 18278-3:2017 specifies procedures for the determination of the acceptable welding current range and the electrode life for spot weld bonding using resistance spot welding with adhesive bonding. ISO 18278-3:2017 is applicable for the evaluation of the weldability of prepared assemblies of uncoated and coated metal sheets with individual thicknesses from 0,4 mm to 6,0 mm.

ISO 14272:2016 specifies specimen dimensions and a testing procedure for the cross tension testing of spot and projection welds in overlapping sheets in any metallic material of thickness 0,5 mm to 3 mm, where the welds have a maximum diameter of 7√t (where t is the sheet thickness in mm). The object of cross tension testing is to determine the tensile force that the test specimen can sustain.

ISO 14270:2016 specifies specimen dimensions and a testing procedure for mechanized peel testing of single spot, seam and embossed projection welds, in overlapping sheets, in any metallic material of thickness 0,5 mm to 3 mm, where the welds have a maximum diameter of 7√t (where t is the sheet thickness in mm). For welds of diameter between 5√t and 7√t, the peel strength values obtained may be lower than expected when using the recommended test specimen dimensions because the test specimen width is designed for welds of diameter of 5√t or less. The object of mechanized peel testing is to determine the peel strength that the test specimen can sustain.

ISO 14273:2016 specifies specimen dimensions and a testing procedure for tensile shear testing of spot and embossed projection welds, in overlapping sheets, in any metallic material of thickness 0,5 mm to 10 mm, where the welds have a maximum diameter of 7√t (where t is the sheet thickness in mm). The object of tensile shear testing is to determine the tensile shear force that the test specimen can sustain.

ISO 18278-2:2016 provides specific test procedures for the determination of the acceptable welding current range and the electrode life. It is applicable for the evaluation of the weldability of assemblies of uncoated and coated sheets of individual thicknesses from 0,4 mm to 6,0 mm.

ISO 18278-1:2015 specifies procedures for assessing the generic weldability for resistance welding of uncoated and coated metals. It is assumed for this and other linked standards that their application is entrusted to appropriately trained, skilled, and experienced personnel. For the quality of welded structures, the relevant part of ISO 14554 is applicable. The specification of procedures is to follow guidelines as in ISO 15609‑5. The purpose of the tests are to a) compare the metallurgical weldability of different metals, b) assess the weldability of differing component designs, e.g. dimensional configuration, stack-up, projection geometry, etc., c) investigate the effect of changes in welding parameters such as welding current, weld time, electrode force or complex welding schedules including pulse welding, current stepping etc. on weldability, and/or d) compare the performance of resistance welding equipment. Precise details of the test procedure to be used will depend on which aspect of items a) to d) will be evaluated relative to the welding result obtained.

ISO 14373:2015 specifies requirements for resistance spot welding in the fabrication of assemblies of uncoated and metallic coated low carbon steel, comprising two or three sheets of metal, where the maximum single sheet thickness of components to be welded is within the range 0,4 mm to 3 mm, for the following materials: uncoated steels; hot-dip zinc or iron-zinc alloy (galvannealed) coated steel; electrolytic zinc, zinc-iron, or zinc-nickel coated steel; aluminium coated steel; zinc-aluminium coated steel. It is applicable to welding of sheets of the same or dissimilar thickness, where the thickness ratio is less than or equal to 3:1. It applies to the welding of three thicknesses, where the total thickness is less than or equal to 9 mm. Welding with the following types of equipment is within its scope: pedestal welding equipment; gun welders; automatic welding equipment where the components are fed by robots or automatic feeding equipment; multi welders; robotic welders. It also gives information, for guidance only, on appropriate welding equipment on spot welding conditions. The welding of organic coated or primer coated steels is not within its scope.

ISO 14323:2015 specifies specimen dimensions and testing procedures for impact tensile shear and cross-tension testing of resistance spot and embossed projection welds in overlapping sheets, in any metallic material of thickness 0,5 mm to 4 mm.

ISO 10447:2015 specifies the procedures and recommended tooling to be used for peel and chisel testing of resistance spot and projection welds. ISO 10447:2015 applies to welds made in two or more sheets in the thickness range of 0,5 mm to 3,0 mm. The aim of these tests is to determine - weld size and failure type when welds are destructively tested, and - verification of welds by non-destructive chisel tests.

ISO 15614-12:2014 specifies the tests which can be used for qualification of welding procedure specifications for spot, seam, and projection welding processes. It is part of the ISO 15614 series, details of which are given in ISO 15607, Annex A. ISO 15614-12:2014 defines the conditions for carrying out tests and the limits of validity of a qualified welding procedure for all practical welding operations covered by it.

ISO 14554-2:2013 specifies requirements for the demonstration of the capability of a manufacturer or a sub-contractor to produce welded constructions, fulfilling specified quality requirements, in one or more of the following: a) a contract between involved parties; b) an application standard; c) a regulatory requirement. The requirements contained within ISO 14554-2:2013 can be adopted in full or can be selectively deleted by the manufacturer if not applicable to the construction concerned. They provide a flexible framework for the control of welding by providing specific requirments for: 1) Case 1 ? resistance welding in contracts which require the manufacturer or sub-contractor to have a quality system other than ISO 9001[1] and where the documented welding control has a minor importance to the overall integrity of the final construction; 2) Case 2 ? resistance welding as guidance to a manufacturer or sub-contractor developing a quality system; 3) Case 3 ? references in application standards which use resistance welding as part of their requirements or in a contract between relevant parties. ISO 14554-2:2013: i) is independent of the type of welded construction to be manufactured; ii) defines quality requirements for welding both in production plants and on site; iii) provides guidance for describing the capability of a manufacturer to produce welded constructions to meet specified requirements; iv) can also be used as a basis for assessing the manufacturer in respect to his welding capability. For general guidelines for selection and use, see ISO 3834‑1, while being aware that only comprehensive and elementary requirements are specified for resistance welding. An annex gives a summary comparison of specific quality requirements for resistance welding in ISO 14554-2:2013 and ISO 14554‑1.

ISO 14554-1:2013 specifies requirements for the demonstration of the capability of a manufacturer or a sub-contractor to produce welded constructions, fulfilling specified quality requirements, in one or more of the following: a) a contract between involved parties; b) an application standard; c) a regulatory requirement. The requirements contained within ISO 14554-1:2013 can be adopted in full or can be selectively deleted by the manufacturer if not applicable to the construction concerned. They provide a flexible framework for the control of welding by providing specific requirements for: 1) Case 1 ? resistance welding in contracts which require the manufacturer or sub-contractor to have a quality system in accordance with ISO 9001; 2) Case 2 ? resistance welding in contracts which require the manufacturer or sub-contractor to have a quality system other than ISO 9001; 3) Case 3 ? resistance welding as guidance to a manufacturer or sub-contractor developing a quality system; 4) Case 4 ? references in application standards which use resistance welding as part of their requirements or in a contract between relevant parties, although it is more appropriate for ISO 14554‑2 to be used in such cases. ISO 14554-1:2013: i) is independent of the type of welded construction to be manufactured; ii) defines quality requirements for welding both in production plants and on site; iii) provides guidance for describing the capability of a manufacturer to produce welded constructions to meet specified requirements; iv) can also be used as a basis for assessing the manufacturer in respect to his welding capability. For general guidelines for selection and use, see ISO 3834‑1, while being aware that only comprehensive and elementary quality requirements are specified for resistance welding. An annex gives a summary comparison of specific quality requirements for resistance welding in ISO 14554-1:2013 and ISO 14554‑2.

ISO 15614-13:2012 specifies tests for the qualification of welding procedure specifications applicable to upset (resistance butt) welding and flash welding of metallic materials, e.g. with solid, tubular, flat or circular cross-section. Its basic principles can also be applied to other resistance welding processes when this is stated in the specification. ISO 15614-13:2012 defines the conditions for carrying out tests and the limits of validity of a qualified welding procedure for all the practical welding operations that it covers. The tests required to qualify the procedure for a particular component or assembly depend on the performance and quality requirements of the component or assembly, as defined in the design specification. The tests are intended to be carried out in accordance with the requirements of ISO 15614-13:2012, unless more severe tests are specified by the relevant application standard or specification and when these apply. ISO 15614-13:2012 covers the following resistance welding processes, as defined in ISO 4063: 24 flash welding, using direct current or alternating current with various movement sequences, constant flashing and pulsed flashing; 25 resistance upset welding, using direct current or alternating current with various pressure sequences.

1 Scope This International Standard specifies specimen dimensions, testing equipment and the procedure for torsion testing of resistance spot welds with single sheet thicknesses ranging from 0,5 mm to 6,0 mm in steels. It can be used for non-ferrous materials in certain circumstances. The aim of this International Standard is to determine the weld diameter and the failure type of fractured specimens, and to evaluate the influence of different steel types, welding parameters and other factors on the deformation characteristics of a resistance spot weld.

ISO 15609-5:2011 specifies requirements for the content of welding procedure specifications for resistance spot, seam, butt and projection welding processes. It is necessary to establish the acceptability of applying the principles of ISO 15609-5:2011 to other resistance and related welding processes before any qualification is undertaken. Variables listed in ISO 15609-5:2011 are those influencing either weld dimensions (quality), weld nugget dimension, weld pattern positioning, mechanical properties or geometry of the welded joint.

ISO 27654:2011 specifies the pressure test method to be applied to resistance-seam-welded specimens of different types of materials with single sheet thicknesses ranging from 0,3 mm to 3,2 mm. The purpose of this pressure test is to determine the suitability of the material, welding equipment, welding parameters and of other factors on a tank, a vessel or a container for liquids or gases, which are manufactured by resistance seam welding.

ISO 18595:2007 specifies requirements for resistance spot welding in the fabrication of assemblies of aluminium sheet, extrusions (both work- and age-hardening alloys) and/or cast material comprising two or three thicknesses of metal, where the maximum single (sheet) thickness of components to be welded is within the range 0,6 mm to 6 mm. ISO 18595:2007 is applicable to the welding of sheets or plates of dissimilar thickness where the thickness ratio is less than or equal to 3:1. It applies to the welding of three thicknesses where the total thickness is less than or equal to 9 mm. Welding with the following types of machines is within the scope of ISO 18595:2007: pedestal welding machines; gun welders; automatic welding equipment where the components are fed by robots or automatic feeding equipment; multi-welders; robotic welders. The welding of coated material, e. g. zinc coated or anodised material, is not within the scope of ISO 18595:2007.

ISO 18594:2007 specifies the procedure and the experimental set-up for determining the transition resistance of a single sheet or two overlapping sheets of aluminium or steel, with or without surface treatment, and with or without surface coating.

ISO16433:2006 specifies requirements for resistance seam welding in the fabrication of assemblies of uncoated and metallic coated low carbon steel comprising two sheets of metal, where the maximum single sheet thickness of components to be welded is within the range 0,4 mm to 3 mm for the following materials: uncoated steels; hot-dip zinc or iron-zinc alloy (galvannealed) coated steel; electrolytic zinc, zinc-iron, or zinc-nickel coated steel; aluminium coated steel; zinc-aluminium coated steel.

ISO 16432:2006 specifies requirements for embossed-resistance-projection welding in the fabrication of assemblies of uncoated and metallic coated low carbon steel comprising two thicknesses of metal, where the maximum single sheet thickness of components to be welded is within the range 0,4 mm to 3 mm for the following materials: uncoated steels; hot-dip zinc or iron-zinc alloy (galvannealed) coated steel; electrolytic zinc, zinc-iron, or zinc-nickel coated steel; aluminium coated steel; zinc-aluminium coated steel. Organic coated or primer coated steels are not covered by ISO 16432:2006.

ISO 14327:2004 specifies procedures for determining the weldability lobe for producing quality welds. The tests are used in particular to determine the weldability lobe for coated/uncoated steels, stainless steels and aluminium and its alloys but may also be used for other metallic materials. The aim of this procedure is to allow determination of the range of welding parameters which give rise to an acceptable weld quality as defined within precise limits. The procedure can be used to determine: The influence of electrode material, electrode shape and dimensions on the available welding range for a particular material and welding machine. The influence of material type and thickness on the available welding range when using a particular combination of welding electrodes and welding machine. The influence of welding machine type, or electrode cooling on the available welding range for a particular material using a particular electrode shape. The available welding range in a production situation.

ISO 14324:2003 specifies test specimens and procedures for fatigue testing spot welds, at ambient conditions, under repeated tensile loading to produce either shear or cross-tension loading of the spot weld, in steel of sheet thicknesses of 0,5 mm to 6 mm. The test results are not, in general, directly applicable to the fatigue behaviour of a spot-welded component or structure. This procedure can be used for other materials provided proper test conditions (e.g., heating) have been determined.

Specifies the characteristics and dimensions of projections for resistance welding. Includes also the appropriate design and dimensions for tools (see annex B). The projections may be used on either hot-rolled or cold-rolled, uncoated mild steel, of conventional welding quality and up to 3 mm thick, as single projections, in multiples or as a group of multiples.

ISO 18592:2009 specifies test specimens and procedures for performing constant load amplitude fatigue tests on multi-spot-welded and multi-axial specimens in the thickness range from 0,5 mm to 5 mm at room temperature and a relative humidity of max. 80 %. The applicability of ISO 18592:2009 to larger thicknesses can be limited by mechanical properties such as yield strength and formability of the specimen material. The thickness range for advanced high strength steels (AHSs) is generally below 3,0 mm. Greater thicknesses apply for aluminium alloys, for example. Depending on the specimen used, it is possible from the results to evaluate the fatigue behaviour of: a) spot welds subjected to defined uniform load distribution; b) spot welds subjected to defined non-uniform load distribution; c) spot welds subjected to different defined combinations of shear-, peel-and normal-tension loads; and d) the tested specimen. Multi-spot specimens with which the different load distributions can be realized are: 1) defined uniform load distribution; 2) defined non-uniform load distribution; 3) defined combinations of shear-, peel- and normal-tension loads; 4) spot welds subjected to undefined non-uniform load distribution. The specimens and tests referred to under 4) are not dealt with further in ISO 18592:2009, because the results obtained with these specimens are specific to the components as tested and may not be generalized or used for deriving data pertaining to the load-carrying behaviour of the welds. Results obtained with such tests are suitable for comparing the mechanical properties of the tested components with those of similar components tested in the same manner. These tests are, however, not suitable for evaluating or comparing the load-carrying properties of the welds. The test results of the fatigue tests obtained with component like specimens are suitable for deriving criteria for the selection of materials and thickness combinations for structures and components subjected to cyclic loading. This statement is especially relevant for results obtained with specimens with boundary conditions, i.e. a local stiffness similar to that of the structure in question. The results of a fatigue test are suitable for direct application to design only when the loading conditions in service and the stiffness of the design in the joint area are identical.

ISO 15614-13:2005 specifies the tests which should be used for qualification of welding procedure specifications. It applies to resistance butt welding and flash welding of metallic materials, e.g. with solid, tubular, flat or circular cross-section. The basic principles of ISO 15614-13:2005 may be applied to other resistance welding processes when this is specified in the specification. ISO 15614-13:2005 defines the conditions for carrying out tests and the limits of validity of a qualified welding procedure for all practical welding operations covered by ISO 15614-13:2005. ISO 15614-13:2005 covers the following resistance welding processes as defined in ISO 4063: 24 flash welding using direct current or alternating current with various movement sequences, constant flashing and pulsed flashing; 25 resistance butt welding, using direct current or alternating current with various pressure sequences.

ISO 18278-1:2004 recommends procedures for determining the generic weldability for resistance spot, seam and projection welding of metallic materials. This procedure is applicable for the assessment of the weldability of uncoated/coated steels, stainless steels and non-ferrous alloys such as aluminium, titanium, magnesium and nickel and their alloys of single thickness lower than or equal to 5 mm. The weldability of metallic materials in resistance welding is defined in terms of: the ability to make the weld in the first place; the ability to continue making welds; the ability of the weld to withstand the imposed service stresses. The procedures recommended in ISO 18278-1:2004 can be used to: compare the weldability of different metallic materials; compare the welding response of particular welding equipment and allow comparisons between different equipment and determine the influence of the static/dynamic properties of different welding equipment; determine the weldability of a material when any welding configuration is changed e.g. electrode material and/or shape, water cooling requirements etc.; investigate the effect of welding parameters such as welding current, weld time, electrode force or complex welding schedules including pulse welding, current stepping etc. on weldability.

ISO 18278-2:2004 specifies a laboratory test procedure for the determination of the acceptable welding current range and the assessment of electrode life using a multi-spot test with specific conditions. ISO 18278-2:2004 is applicable for the assessment of the weldability of uncoated and coated sheet steels of thicknesses up to 3 mm. The test procedure specified in this International Standard and the results obtained, apply only for the introduction of a new type or batch of material.

ISO 15609-5:2004 specifies requirements for the content of welding procedure specifications for resistance spot, seam, butt and projection welding processes. The acceptability of applying the principles of this International Standard to other resistance and related welding processes should be established before any qualification is undertaken. Variables listed in ISO 15609-5:2004 are those influencing either weld dimensions (quality), weld nugget dimension, weld pattern positioning, mechanical properties or geometry of the welded joint.

ISO 15614-12:2004 specifies the tests which may be used for qualification of welding procedure specifications for spot, seam and projection welding processes. ISO 15614-12:2004 defines the conditions for carrying out tests and the limits of validity of a qualified welding procedure for all practical welding operations covered by this International Standard. Tests shall be carried out in accordance with this International Standard unless more severe tests are specified by the relevant application standard or contract when these shall apply. The acceptability of applying the principles of this International Standard to other resistance welding processes should be established before any qualification is undertaken. ISO 15614-12:2004 covers the following resistance welding processes: - spot welding; - indirect spot welding; - direct spot welding; - seam welding; - lap seam welding; - mash seam welding; - fail butt-seam welding; - seam welding with strip; - projection welding; - indirect projection welding; - direct projection welding.

ISO 14329:2003 specifies the definitions of the geometric measurements and fracture types to be used in relation to the testing of resistance spot, projection and seam welds in which different loading configurations cause different stress distributions in the weld. The aim of these definitions is to give a base for all other related standards.

ISO 17654:2003 specifies the pressure test method to be applied to resistance seam welded specimens of different types of material, e.g. uncoated and coated ferritic steels and uncoated austenitic steel sheet with single sheet thicknesses ranging from 0,3 mm to 3,2 mm. The purpose of this pressure test is to determine the suitability of the material, welding equipment, welding parameters and of other factors on a tank, a vessel or a container for liquids or gases, which are manufactured by resistance seam welding.

ISO 17653:2003 is applicable to spot welded test specimens with single sheet thicknesses ranging from 0,5 mm to 3,0 mm in steels. It may be used for non-ferrous materials in certain circumstances. The aim of this test is to determine the influence of different steel types, welding parameters and other factors on the deformation characteristics of a spot weld. Using this test, it is possible to determine the weld diameter and the fracture type from fractured specimens. Additionally, the maximum torsion moment (torque) and the corresponding torsion angle can be determined.