Caracterización de juntas soldadas en acero inoxidable AISI 304 mediante los procesos SMAW, GMAW y GTAW

Abstract

The aim of this work is to characterize the welded joints in stainless steel AISI 304 by means of the welding processes SMAW, GMAW and GTAW. In that way, changes in microstructure, HAZ, mechanical properties and costs in each process are related. In order to check the purchased base material composition, a spectrometry analysis by spark emission was made, this analysis reveals the material actual composition. Also, a tensile test was done to verify the mechanical properties of this material. For the experimental analysis, the plates were prepared with the right separation and bezel for each process. Once the welded joints were obtained, non-destructive tests were made, visual testing, liquid penetrant and radiographic. Destructive tests were performed as well: tensile test, face and root bend. In addition, hardness mappings with Rockwell B scale at the welding surroundings were done. AWS D1.6 standard was taken as a reference to establish the acceptance criteria of the performed tests. Comparisons among the three process were done to define which one produces: welding with higher tensile strength, smaller HAZ and involves less cost. These results were used to find the most suitable process for the welding of the studied material. Finally, it was found that the most adequate process considering both technical and economic aspects for the plate welding of the stainless steel AISI 304 was GMAW.