Shiraz UniversityIranian Journal of Science and Technology Transactions of Mechanical Engineering2228-618738M220141001EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES AND MICROSTRUCTURES IN A 36 REPAIR BUTT WELDMENT431438250610.22099/ijstm.2014.2506ENJournal Article20121015Welding is one of the usual assembling methods with various applications. The<br />different defects are generated during welding and also in service conditions. After inspection and<br />identifying the defects, the repairs are applied. Welding repair operation causes the mechanical<br />properties and the microstructures of weldment to change. In the present work the variations of<br />yield stress, hardness and microstructures in the A 36 repair butt specimens were investigated by<br />the experimental study. The welding technique was Tungsten Insert Gas method without using<br />filler. The specimens were cut from the welded plates using water jet method for avoiding heat<br />effect during the cutting. The low-carbon steel A 36 thin plate was used to construct the<br />specimens. This material has numerous applications to construct various structures and parts. The<br />specifications of specimens and tests were selected according to the standards. The tensile tests<br />were performed for four numbers of each specimen. The mean of yield stresses in the specimens<br />were reduced after the repairing through half- thickness of the butt welds. Moreover, the mean of<br />yield stresses in the specimens after repairing would be decreased if the welding voltage and<br />current increased. Reduction of the hardness in heat affected zone and variation of the phases and<br />grain size after repairing were other outcomes from testing on the specimens.Shiraz UniversityIranian Journal of Science and Technology Transactions of Mechanical Engineering2228-618738M220141001NONDESTRUCTIVE EVALUATION OF MECHANICAL PROPERTIES OF DUCTILE CAST IRON PARTS USING EDDY CURRENT SIGNALS439443250710.22099/ijstm.2014.2507ENJournal Article20110817The present research investigates improvement of Eddy Current (EC) technique as a<br />nondestructive method for measurement of ductile cast iron microstructural and mechanical<br />characteristics. Six samples of heat treated ductile cast iron have been selected to study the<br />relations between pearlite content and EC outputs. These outputs include voltage and normalized<br />impedance as well as calculated parameters of harmonic analysis. Furthermore, correlation<br />between mechanical properties such as hardness, yield strength and ultimate tensile strength in<br />samples containing different ferrite-pearlite matrices and the magnetic responses has also been<br />found. High correlation coefficients of the relations indicate an acceptable level of accuracy in<br />comparison with destructive method.