Welding continues to be the preferred method of joining metal parts. As welding becomes more digital, the technology becomes more complex, but its application as a process becomes simpler and more efficient. Worldwide, welding continues to grow, and that growth is dependent upon the growth of the steel and other metal industries. Since the last edition ofModern Welding Technology,much has changed in the world of welding. New processes have been born, and others have gotten married. There are now combinations of welding processes known ashybrid welding.Welding power sources have continued to get smaller, more efficient, lighter, and more controllable. Some welding processes have become more popular and others more refined. For example, the laser is more widely used, especially for cutting, and a new process, stir friction welding, is starting to be used to join aluminum for automotive and space applications. The need to improve weld quality and reduce welding costs continues to drive the welding industry. This is the highest priority because of improved materials and fabricating methods. Semiautomatic welding has largely replaced manual welding, and automatic and robotic welding are fording more applications in the industry. Adaptive control is rapidly becoming more widely used. More powerful computer controls and more rugged sensors are being used. All of this has helped take the human welder farther away from the arc and fumes and has helped clean up the welder's environment. Throughout the world many new alloys are being developed. Metals compete with plastics, composites, ceramics, and any material that will serve the need. The end result is the most economical material for a given application. Many new steels and alloys are being welded today, including higher strength thermomechanically processed steels. Steels with lower carbon and lower impurity elements are available with high strengths based on the particular heat treatment. New steels for high-temperature applications have been developed. New grades of stainless steel that combat corrosion are appearing. New aluminums containing lithium and other elements are being utilized in the aircraft industry. Nonmetallic materials are advancing. Plastics have been greatly improved, and there are now composite beams available to build bridges. Ultimately, the most suitable material for the lowest price will be used for every application. The welding industry will determine the welding method. Welding education and training are changing. Today there is less emphasis on skill training for manual welding, but more emphasis on technology training. We must be able to select the proper application of welding to increase productivity. A more thorough understanding is needed. That is the purpose of this book. A major breakthrough has been accomplished by the joint American Welding Society (AWS) and the Welding Research Council program for providing the optimum way to make a quality weld. Standard welding procedures have been issued that show the preferred way to make a particular weld. As a result, welding costs should be greatly reduced because standard procedures save the expense of duplicating qualifying procedures and allow the portability of welding credentials. It is a great step forward. The American Welding Society continues to make welding-related occupations more professional. Through standardizing the qualification and certification of personnel, public confidence in welding will increase. AWS has become the welding authority in the United States and is providing ways to educate welding inspectors, teachers, technicians, and engineers. This is done through increased training, testing, and certification of knowledge, based on proficiency testing. The original concept of this book has been maintained, with emphasis on the arc welding processes and the use of steel for industrial and construction uses. The book still foScott Helzer is the author of 'Modern Welding Technology (6th Edition)', published 2004 under ISBN 9780131130296 and ISBN 0131130293.