1、FTZSTSTA RWMARESISTANCE WELDING MANUAL Revised Fourth Edition RWMARWMA Library of Congress Number: 89-063296 International Standard Book Number: 0-9624382-0-0 Resistance Welder Manufacturers Association, 1900 Arch Street, Philadelphia, PA 19103 www.rwma.org 2003 by the Resistance Welder Manufacturer
2、s Association (RWMA). All rights reserved. This Manual is intended to describe the basic fundamentals of Resistance Welding in its various applications with differing materials and equipment. It covers some safety considera- tions, but it is not a safety manual. It covers some materials standards, b
3、ut, except where specifically identified (e.g., RWMA Electrode Material Standards), it does not set, describe or replace specific industrial or material standards or specifications. It describes the operations, but it is not an operating manual. This Manual is not intended to replace rules, laws, re
4、gulations, standards, directions or specifications relating to safety, design, operations, materials or procedures. All relevant federal and state laws, regulations and standards and all privately created standards should be followed. The Resistance Welder Manufacturers Association, and those acting
5、 for it in preparation of this Manual, will not be responsible for any injury or person or property, or for compensatory, consequential or punitive damages or payments, resulting in whole or part from the use of this Manual. Printed in the United States of America, by George H Buchanan, Bridgeport,
6、NJ.PREFACE The Resistance Welder Manufacturers Association (RWMA) takes extreme pride in presenting the Revised Fourth Edition of the Resistance Welding Manual. At its publishing, this work represents the latest and most complete com- pilation of basic information on resistance welding available any
7、where. The text gathers together the most current data on resistance welding which includes: the different welding processes; types and weldability of various mate- rials; and resistance welding equipment, such as welding machines, electrodes, jigs and fixtures, transformers, con- trols and power su
8、pplies. Also covered, are modern quality control (S.P.C.) and maintenance procedures. This organization, representing North American builders of all types of resistance welding equipment, has a long tradition of providing practical information and assistance to those using and studying this vital we
9、lding process, and of developing standards to serve the entire resistance welding industry. The RWMA has grown in parallel with the industry it serves, reaching its greatest strength as resistance welding gains new recognition for speed and pro- ductivity in automotive, appliance, transport, aerospa
10、ce, electronics and consumer goods manufacturing. An organization such as the RWMA depends on countless hours of unpaid work by member and non-member representatives to bring a massive project like this reference work to fruition. For some individuals, publication of this book represents the finest
11、possible testimony to their dedication. The RWMA wishes to gratefully acknowledge the efforts of literally dozens of member delegates who gave unselfishly of their time working on this volume as part of the Association. March, 2003 RWMA, Philadelphia, PA RWMA MiThe reference data provided in this re
12、vised edition is the product of an indeter- minable amount of hours of charitable contribution by many professionals and orga- nizations. Their work is deeply acknowledged by the RWMA Association; but more important, their contributions will serve to advance the comprehension of resistance welding t
13、hroughout the welding industry. Additionally, state-of-the-art technology and practical resistance welding data will undoubtedly guide significant productivity achievements in the coming years. The entire Resistance Welding Industry will profit from their commitment to this manual. The scope of cove
14、rage, both of resistance welding fundamentals and its advanced applications, will prove useful to engineers, managers and technicians who are en- deavoring to increase their knowledge of resistance welding, upgrade product quality and maximize the use of their manufacturing resources. A comprehensiv
15、e index has been provided which we hope will expedite quick access to information.Also included are illustrations, photographs, and tables to assist information gathering and trouble- shooting. ivACKNOWLEDGEMENTS Machinery Division Automation International, Inc. Banner Welder, Inc. Bergandi Machiner
16、y Company CenterLine (Windor) Ltd. Special Machinery Division Consultores Y Servicios Industriales Cybersmith Engineering Detroit Tool and Engineering Ewald Instruments Corporation Icesa/Modicon Janda Company, Inc. Jenzano, Inc. LORS Machinery, Inc. MIM Industries, Inc. M.L.S. Systems NSRW, Inc. RWC
17、, Inc. Semtorq, Inc. Standard Resistance Welder Co. Division of Jim Dally M INTRODUCTION 1-1 RESISTANCE WELDING PROCESSES 1-1 RELATED PROCESSES 1-3 FUNDAMENTALS OF THE RESISTANCE WELDING PROCESS 1-3 APPLICATIONS 1-8 ECONOMICS 1-9 DESIGN PRINCIPLES 1-12 MATERIALS 1-18 LIMITATIONS 1-18 Spot Welding IN
18、TRODUCTION 2-1 FUNDAMENTALS OF THE PROCESS 2-1 TYPES OF WELDS 2-2 ELECTRODES 2-5 MATERIALS 2-5 WELD QUALITY 2-7 IMPLEMENTATION 2-8 Projection Welding INTRODUCTION 3-1 TYPES OF PROJECTIONS 3-3 GENERAL PRINCIPLES 3-8 WELD QUALITY 3-12 Seam Welding 4 INTRODUCTION 4-1 FUNDAMENTALS OF THE PROCESS 4-2 WEL
19、D QUALITY 4-8 MATERIALS 4-11 Flash And Upset Welding 5 FUNDAMENTALS OF THE PROCESS 5-1 APPLICATIONS 5-3 EQUIPMENT 5-3 WELDING PROCEDURES 5-7 PROCESS VARIABLES 5-11 WELD QUALITY 5-13 TESTING AND INSPECTION 5-15 WELDING OF STEEL 5-15 UPSET WELDING 5-18 viiContents Additional Resistance Welding Process
20、es CROSS WIRE WELDING 6-1 RESISTANCE BRAZING 6-4 HOT RIVETING AND UPSETTING 6-10 PERCUSSION WELDING 6-12 BUTT SEAM WELDING 6-14 RESISTANCE CUTTING 6-16 Section 2 MATERIALS Low Carbon Steels 7A_ INTRODUCTION 7-1 GENERAL PRINCIPLES 7-1 SPOT WELDING 7-3 PROJECTION WELDING 7-11 SEAM WELDING 7-12 ROLL SP
21、OT WELDS 7-13 MASH SEAM WELDS 7-13 FLASH WELDING 7-13 UPSET WELDING 7-16 RESISTANCE WELDS IN SCALY STOCK 7-17 High Carbon And Low Alloy Steels 6 INTRODUCTION 8-1 GENERAL PRINCIPLES 8-1 SPOT WELDING 8-3 SEAM WELDING 8-12 FLASH WELDING 8-12 HIGH STRENGTH LOW ALLOY STEEL (HSLA) 8-14 Stainless And High
22、Alloy Steels JM INTRODUCTION 9-1 GENERAL PRINCIPLES 9-1 SPOT WELDING 9-5 PROJECTION WELDING 9-8 ROLL SPOT AND SEAM WELDING 9-8 FLASH WELDING 9-8 STAINLESS-CLAD STEEL 9-9 Coated And Plated Steels 10-1 SPOT WELDING 10-1 PROJECTION WELDING 10-5 SEAM WELDING 10-5 FLASH WELDING 10-5 viiiContents Aluminum
23、 And Aluminum Alloys 11-1 INTRODUCTION 11-1 MATERIAL PREPARATION 11-3 SPOT WELDING 11-5 QUALITY CONTROL 11-24 ELECTRODES 11-29 SEAM AND ROLL SPOT WELDING 11-30 PROJECTION WELDING 11-33 UPSET WELDING 11-33 FLASH WELDING 11-34 Magnesium And Magnesium Alloys 12-1 INTRODUCTION 12-1 SPOT WELDING 12-2 FLA
24、SH WELDING 12-3 Copper And Copper Base Alloys 13-1 INTRODUCTION 13-1 ALLOYING AGENTS 13-1 COPPER BASE ALLOYS 13-3 GENERAL PRINCIPLES 13-5 SPOT WELDING 13-7 PROJECTION WELDING 13-10 SEAM WELDING 13-10 FLASH WELDING 13-11 Nickel And Nickel-Base Alloys 14-1 INTRODUCTION 14-1 SPOT WELDING 14-6 PROJECTIO
25、N WELDING 14-15 CROSS WIRE WELDING 14-15 SEAM WELDING 14-16 FLASH WELDING 14-18 Miscellaneous And Dissimilar Metals 15-1 TITANIUM 15-1 COBALT BASE ALLOYS 15-2 REFRACTORY METALS 15-4 ZINC AND ZINC DIE CASTINGS 15-4 LEAD AND LEAD ALLOYS 15-5 DISSIMILAR METALS 15-5 ixContents Section 3 EQUIPMENT Machin
26、es 16-1 INTRODUCTION 16-1 ROCKER ARM MACHINES 16-2 BENCH MOUNTED WELDING MACHINES 16-4 PRESS TYPE WELDING MACHINES 16-5 SEAM WELDING MACHINES 16-6 FLASH AND UPSET WELDING MACHINES 16-8 MULTIPLE SPOT WELDING MACHINES 16-11 PORTABLE GUN WELDING MACHINES 16-13 ROBOT SYSTEMS INTEGRATION 16-15 HIGH FREQU
27、ENCY WELDING 16-16 MISCELLANEOUS MACHINES 16-17 Jigs, Fixtures And Tooling 17-1 INTRODUCTION 17-1 WORKHOLDING DEVICES 17-10 JIGS AND FIXTURES FOR GUN WELDING MACHINES 17-12 HOPPER AND MAGAZINE FEEDS 17-13 SEAM WELDING FIXTURES 17-15 FLASH AND UPSET WELDING MACHINE CLAMPING FIXURES 17-15 TYPES OF OPE
28、RATION 17-16 BACKUPS AND LOCATORS 17-17 Resistance Welding Electrodes 18-1 INTRODUCTION 18-1 ELECTRODE FUNCTIONS 18-1 ELECTRODE MATERIALS 18-2 FACTORS AFFECTING CHOICE OF ELECTRODE MATERIALS 18-11 SPOT WELDING ELECTRODES 18-12 PROJECTION WELDING ELECTRODES 18-24 SEAM WELDING ELECTRODES 18-25 UPSET A
29、ND FLASH WELDING ELECTRODES 18-26 PROPER ELECTRODE COOLING 18-27 Welding Transformers And Power Conversion Equipment 19-1 INTRODUCTION 19-1 ELECTRICAL SYSTEM 19-1 SINGLE-PHASE RESISTANCE WELDING TRANSFORMERS 19-4 FREQUENCY CONVERTER SYSTEM 19-9 HIGH FREQUENCY DIRECT CURRENT WELDING POWER SUPPLIES 19
30、-11 DIRECT-CURRENT POWER CONVERSION EQUIPMENT 19-11Contents Welding Controls 20-1 INTRODUCTION 20-1 CONTROL SYSTEMS 20-1 CONTROL TECHNOLOGIES 20-3 STANDARD NEMA CLASSIFICATIONS 20-4 USER INTERFACE 20-5 CONTACTORS 20-6 HEAT CONTROL 20-7 COMPENSATION AND FEEDBACK SYSTEMS 20-11 COOLING REQUIREMENTS 20-
31、14 Power Supply 21-1 INTRODUCTION 21-1 OUT-PLANT POWER SUPPLY SYSTEM 21-1 IN-PLANT POWER SUPPLY SYSTEM 21-7 Instrumentation 22-1 INTRODUCTION 22-1 PROCESS VARIABLES 22-2 EQUIPMENT AVAILABLE 22-5 Fluid Power Systems 23-1 INTRODUCTION 23-1 FLUIDS 23-1 PRESSURE SUPPLY SYSTEMS 23-2 CYLINDERS 23-7 SYSTEM
32、 SELECTION 23-14 Quality Control 24 INTRODUCTION 24-1 PERSONNEL 24-1 FACTORS AND VARIABLES AFFECTING WELD QUALITY 24-1 OPERATOR 24-4 STANDARD METHODS FOR TESTING RESISTANCE WELDS 24-4 APPLICATION OF STANDARD METHODS FOR MECHANICAL TESTING OF RESISTANCE WELDS 24-27 Maintenance And Service 25-1 INTROD
33、UCTION 25-1 INSTALLATION OF EQUIPMENT 25-1 SETUP OF EQUIPMENT 25-4 MACHINE AND EQUIPMENT MAINTENANCE 25-4 PERIODIC INSPECTION AND SERVICE 25-11 SPARE PARTS 25-14 SYMBOLS AND ABBREVIATIONS M INDEX 11-1 xiPROCESSES SECTION 1 Fundamentals Of Resistance Welding 1 Spot Welding 2 Projection Welding 3 Seam
34、 Welding 4 Flash and Upset Welding 5 Additional Resistance Welding Processes 61 Fundamentals Of Resistance Welding INTRODUCTION W elding consists of the joining of two or more pieces of metal by the application of heat and sometimes of pressure. Resistance welding embraces that branch of the welding
35、 art in which the welding heat in the parts to be welded is generated by the resistance offered by these parts to the passage of an electrical current. It dif- fers from other forms of welding in that no extraneous materials, such as fluxes, filler rods, etc. are used; therefore, the metallography o
36、f the weld is not com- plicated by the addition of these materials. Resistance welding further differs from the fusion welding processes, by utilizing the application of mechanical force to forge the heated parts together. The effect of the force is to refine the grain structure, thus produc- ing a
37、weld with physical properties, in most cases, equal to the parent metal, and sometimes even superior. Resistance welding machines and their operation often appear mysterious to the layman when he sees good welds being made quickly and easily. The same characteristics may lead the beginner to believe
38、 the process more simple, or more generally applicable, than is true. It is the aim of this introductory discus- sion to review the fundamentals of the process and to discuss some of the more basic details. Welding is really a metallurgical process. Ordinary iron has been described as a suspension o
39、f ferrite crys- tals of variable compositions in a matrix of its own impurities. It is this matrix of impurities that increases the electrical resistance of all metals which is of real importance in electrical resistance welding. RESISTANCE WELDING PROCESSES Figure 1.1 illustrates, in graphic form,
40、the resistance welding processes1 and their relation to one another. It should be noted from this chart that the general sub- ject of resistance welding may be broken into two gen- eral classifications according to the method of joining the parts. (The same classifications may also be applied to oth
41、er welding processes). See also the latest revision of Standard Welding Terms and Definitions, an American Welding Society (AWS) publication. 11-2 Fundamentals Of Resistance Welding RESISTANCE WELDING Lap Joints Related Processes Spot Welding Projection Welding Seam Welding Butt Joints Flash Welding
42、 Upset Welding Percussion Welding Resistance Brazing Parting Forging Upsetting Fig. 1.1 - Resistance Welding Processes Lap Joining. This is a method whereby the electrodes conduct the welding current and at the same time apply the welding force. This method includes not only any kind of lap joint bu
43、t also any joint in sheets, plates, rods and bars in which the weld is not made end-to-end or edge-to-edge. Spot Welding. Spot welding is the most widely used example of lap joining, and it is accomplished with shaped electrodes held essentially stationary while the weld is made. Projection Welding.
44、 By forming projections in one or both of the workpieces, the current path is localized at the projections. This permits the use of flat electrodes, thus producing projection welds. Pulsation Welding. Normally a spot or projection weld is made with a single application or impulse of current. If, how
45、ever, the flow of current is interrupted and reapplied one or more times without release of electrode force, a pulsation weld results. Seam Welding. Seam welding is quite similar to spot welding, but the electrodes revolve and are actually in motion while the weld is being made. Roll Spot Welding. I
46、f interrupted current is used regardless of whether the wheels rotate continuously or intermittentlyand if the timing is such that the welds do not overlap, the resulting joint is called a roll spot weld. Butt Joining. Butt joining is that method in which the weld takes place on the ends of bars or
47、the edges of sheets or plates. The electrodes introduce current to the two members being welded, and may or may not be used to transmit the upset force. If they are used to transmit the upset force, it is accomplished through the gripping action of the electrodes or clamp jaws; otherwise, upset forc
48、e is provided by means of auxil- iary clamp members or backup members. Flash Welding. If two rods or bars, for example, are clamped end-to-end, with the abutting ends making light contact with one another when current is applied, a flashing action develops. As this flashing proceeds, metal is burned
49、 away, requiring one piece to be moved toward the other to maintain the flashing action. As this takes place the ends of the two pieces attain weld- ing temperature, at which time an upset force is applied, thereby completing the weld. Upset Welding. If two rods or bars, for example, are clamped end-to-end in electrodes, held in contact with one another as welding current and force is applied, the resultant joint is an upset weld. Percussion Welding. This is usually classed as a resistance welding process, although it technically is
