Evaluación de la soldabilidad del hierro fundido nodular con proceso de soldadura GTAW.

Abstract

In the first chapter a study is made of cast iron, beginning with its chemical composition, main characteristics, types of cast iron that exist today, emphasizing the nodular iron, which is the goal of this project. The second chapter corresponds to the GTAW welding process and parameters that govern it, type of current, shielding gas, electrode filler, filler metal; a brief reference to welding positions, bevel types, technical overview, advantages and disadvantages of the process is done. In the third chapter a study on the weldability of nodular cast iron is performed as recommended by the American Welding Society (AWS D11.2 89-2006), weldability types are analyzed, factors influencing the weldability, is details the solderability test program and the necessary equipment. The fourth chapter corresponds to the experimental process performed to determine the weldability of nodular iron; the selection of base material and the electrode is made, the machining of the specimen and the joint design is specified, non-destructive and destructive testing trials are chosen. In the fifth chapter the results of the processes of preheating of samples are analyzed; with the results of tensile tests and bending a comparison is performed with respect to the initial properties of the base material, the microstructure and the heat affected zone is also analyzed. The sixth chapter corresponds to the general considerations for preparing the welding process, the materials and equipment needed, the most common problems during the welding process and general precautions detailed. In the seventh chapter the conclusions and recommendations of this project are presented.