The analyse of relationship between heat input and heat affected zone for gas metal arc welding process

Welding processes have been also affected positively by technological developments as all engineering processes. However in practice, due to the variety manufactured materials and material types, problems occurred during welding processes have been still investigated. One of the problems is the occurrence of formations on the heat affected zone after welding process.Welding process which has wide range of application in manufacturing industry consists of several methods. One of the premier methods is the Gas Metal Arc Welding process because of its provision of several advantages and facilities in practice.In this study, the relation between heat input and heat affected zone for gas metal arc welding process is analyzed. In the first stage of the study, gas metal arc welding processes are defined generally. In the following stages, information provided from the literature about the structure of heat affected zone and probable occurrence of the formations on the heat affected zone after welding process are presented.In the experimental part of the study, the V welding edge of 60°, 55°, 50°, 45°, 40° were implemented respectively for St37 and AlMgZn samples with the dimensions of 200x160x15 mm. MAG (Metal Active Gas) welding process was applied to St37 sample and MIG (Metal Invert Gas) welding process was applied to AlMgZn sample. After the implementation of welding process on these samples, the width of heat affected zone, the hardness of heat affected zone and the most feasible V welding edge that provides the best penetration were determined. The hardness of welding zone was measured by Micro Vickers Hardness Tester. The widths of the heat affected zones were measured by vernier calipers and the penetration was determined by the macro aspects of the samples.Finally the results obtained from the experimental study were compared with the theoretical calculations. It is seen that the width of heat affected zone of St37 sample obtained from the experiment is relatively similar to the result obtained from the calculations. The width of heat affected zone of AlMgZn samples could not be measured so comparison could not be made for these samples. It is observed that the hardness of the samples obtained from the experiments is relatively similar to the predicted values in the theory. Consequently in this thesis the theoretical and experimental results are compared.Keywords: HAZ, heat input, MIG, MAG, St37, AlMgZn