Resistance welding is a fusion welding process that requires the application of both heat and pressure to achieve a sound joint. The key advantage of resistance welding is that no other materials are needed to create the. These are recommendations only, settings must take account of actual conditions and be verified using a destruct test. This document is not an application manual and does not contain a complete statement of all factors pertaining to those topics. A heat transfer study real and simulated welds were used to develop a model for predicting temperature distribution by z. The weld is made by a combination of heat, pressure, and time.
The symbols shown below are used throughout this manual to call attention to and identify possible hazards. The simplest form of the process is spot welding where the pressure is provided by clamping two or more overlapping sheets between two electrodes fig. Thus, a spot weld made in two sheets, each 1 mm in thickness, would generate a nugget 5 mm in diameter according to the 5t. Specification for resistance welding for aerospace. Do not weld on containers that have held combustibles, or on.
Therefore, if youre wondering what the torque specification should be for your weld nut, simply determine the torque capacity of the fastener itself. Do not spot weld where flying sparks can strike flammable material. Review on techniques for online monitoring of resistance. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. Gm global manufacturing engineering global welding standard test procedures resistance spot welding of steel gws5a.
Resistance welding is the joining of metals by applying pressure and passing current for a length of time through the metal area which is to be joined. Specification for resistance welding for aerospace applications. Resistance spot welding resistance spot welding definition. Resistance spot welding resistance welding is a thermoelectric process where heat is generated at the interface of the parts to be joined by passing an electrical current through them or a precisely controlled time and under a controlled pressure also called force.
An understanding of the resistance welding process is basic to making good welds. One general criterion of resistance spotwelding is that the weld shall have a nugget diameter of 5t 12, t being the thickness of the steel sheet. This specification provides the general resistance welding requirements for aerospace hardware. The d8 aws on automotive welding is responsible for the development of aws standards on all aspects of welding in the automotive industry. Applicationspecific measures, such as the diameter of the welding spot, determine the quality of the joint. The flying sparks, hot workpiece, and hot equipment can cause fires and burns. Standard practice for acoustic emission monitoring during.
The goal of good resistance welding is to focus the heat generated close to the weld interface at the spot where the weld is desired. Montgomery, the ohio state university over the past 20 to 30 years the automotive industry has struggled to reduce weight and increase fuel economy, while at the same time meeting strict crash test standards. Resistance spot welding standards search engineering360. Resistance welding equipment insulated pins for use in electrode backups iso 93.
This document presents standard test methods for evaluating the resistance spot welding behavior of automotive sheet steels. When settingup a new resistance spot welding process optimum parameters must be sought usually using a standard as a guideline and the weld quality must be verified, this is done by destructive testing. So this is all covered by the standard iso, standard 5182 which is, which. Y the symbols shown below are used throughout this manual to call attention to and identify possible hazards.
The american welding society aws publishes over 240 awsdeveloped codes, recommended practices and guides which are written in accordance with american national standards institute ansi practices. Development of high strength steel resistance spot welding. Due to the inaccessibility of nugget in inspection process, usually destructive tests are used to assess weld. Therefore, in recent years, a lot of efforts have been made in. Spot welding is a resistance welding process for joining metal sheets by directly applying opposing forces with electrodes with pointed tips. Resistance welding an overview sciencedirect topics. Although many standards exist advising the range of parameters that should usually be applied for specific materials. An economical joining process in sheet metal processing spot welding of a front end source. Pdf overview of resistance spot welding control researchgate.
Resistance spot welding rsw is one of the common assembling process of thin metals. Protect yourself and others from flying sparks and hot metal. Handbook for resistance spot welding warning this document contains general information about the topics discussed herein. An understanding of the resistance welding process is. It works by contacting copper alloy electrodes to the sheet surfaces, whereby pressure and electric current are applied and heat is generated by the passage of current through. American national standards institute february 22, 2012 test methods for evaluating the resistance spot welding behavior of automotive sheet steel materials 3rd edition supersedes awssae d8. European standards harmonised standards not all en standards are harmonised, only those that are considered to satisfy relevant esrs in product directives. Test methods for evaluating the resistance spot welding. A supplement to resistance welder manufacturers association bulletin 16. This article presents a report on an electromotive force that appears in the electromagnetically open circuit during resistance spot welding. Spot welding is the type of resistance welding when the thermoelectric heat is generated, sequentially, at a usually large number of isolated points spots, where the mating surfaces are pressed together by an external force during the whole welding process. This international standard specifies requirements for resistance spot welding in the fabrication of assemblies of uncoated and metallic coated low carbon steel. A current is then passed between the electrodes, sufficient heat being generated at the interface by.
Accidental contact of electrode to metal objects can cause sparks, explosion, overheating, or fire. Harmonised standards contain an appendix z, which defines which directives and esrs the standard meets. Determination of diameter and thickness of weld nuggets in. Resistance welding ranks among progressive and in practice often used manufacturing techniques of rigid joints. Resistance spot welding is an established joining technology, e. Process planning of resistance spot welding oscar an dersson licentiate thesis in production engineering stockholm, sweden 20 oscar andersson process planning of resistance spot welding kth 20 issn. In general, the highest resistance results in the highest heat assuming that the resistance welding power supply can produce sufficient energy to overcome the resistance. This installation, operation, and maintenance of arc welding equipment and the employment of. It is characterized by a high cost effectiveness and process reliability. Resistance spot welding of battery assemblies nasa.
This international standard specifies the dimensions and tolerances of resistance spot welding electrode caps, where a female taper see iso 1089 is used to fix the cap to an electrode adaptor see iso 51831 and iso 51832. Resistance spot welder standard operating procedure. Resistance spot welding has been widely used for joining sheet metals, especially in automotive and aerospace industries. We make the assumption that the weld on the welded nutstud should be stronger than the fastener itself. We measured the potential drop between the cu electrodes during the supply of an alternating current while keeping the area surrounding the electrical lines available for the potential drop measurement. Diameter of the electrode contact surface should be. Jsa jis z 3144 routine test of resistance spot and. Pdf this paper presents an overview of resistance spot welding control.
Kuka resistance spot welding often just called spot welding is a costeffective joining technology that continues to be very popular in the automotive industry where high reproducibility and automation are essential criteria. Din en iso 14327 resistance welding procedures for determining the weldability lobe for resistance spot, projection and seam welding iso 14327. This international standard applies to welds made in two or more sheets in the thickness range of 0,5 mm to 3,0 mm. Stored energy or capacitor discharge type of resistance welding equipment and control panels involving high voltage over 550 volts shall be suitably insulated and protected by complete enclosures, all doors of which shall be provided with suitable interlocks and contacts wired into the control circuit similar to elevator interlocks. Spot, projection and seam welding british standard iso 176771.
Peel and chisel testing of resistance spot and projection welds. Effect of electrode geometry on resistance spot welding of ahss kevin r. Watch for fire, and keep a fire extinguisher nearby. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to. This specification covers requirements for resistance spot and seam welding of the following metals and their alloys. Check and be sure the area is safe before doing any welding. Wpss used during welding shall satisfy the requirements of this process specification and its applicable. Detection of an electromotive force during resistance spot. The presentation of the physical background of the resistance welding process. Development of high strength steel resistance spot welding parameters and failure analysis by b harvey, b.
Process planning of resistance spot welding oscar an. Spot welding or resistance spot welding is a type of electric resistance welding used to weld various sheet metal products, through a process in which contacting metal surface points are joined by the heat obtained from resistance to electric current. The key advantage of resistance welding is that no other materials are needed to create the bond, which makes this process extremely cost effective. This international standard specifies the procedures and recommended tooling to be used for peel and chisel testing of resistance spot and projection welds. Be alert that welding sparks can easily go through small cracks and openings to adjacent areas. As the name implies, it uses the resistance of the materials to the flow of current that causes. Pdf gm global manufacturing engineering global welding. However, since the formation of weld nugget is invisible in resistance spot welding, traditionally offline destructive test is applied for inspection of the weld quality, which is costly and inefficient. It includes, but is not limited to, resistance spot and resistance seam welding of aluminum, magnesium, iron, nickel, cobalt, and titaniumbased alloys. The current and the heat generation are localized by the form of the electrodes. The document contains a number of tests and test methods useful in determining the resistance spot welding performance of coated and uncoated automotive sheet steels of all strength levels and compositions. Spot welding is a resistance welding process that is used primarily for welding two or more metal sheets together by applying pressure and heat to the weld area. Bohr general motors north america, controls, conveyors, robotics and welding, 30300 mound road, warren, mi 480909015. Specification for resistance welding for aerospace applications 1.
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