En Payam Gheysari, Dr Fathallah Karimzadeh, Dr Ahmad Rezaeian, En Amin Shahsavari,
Volume 3, Issue 2 (Journal OF Welding Science and Technology of Iran 2018)
Abstract
In this research in order to improve the mechanical properties of Aluminium alloy 2024, nanostructure Aluminum sheets were first produced by Cryorolling process and then was welded by resistance spot welding method. For this purpose, the samples solution treated at 495˚C for 55 minute and subsequently cryorolled up to 85% reduction in thickness. For obtaining simultaneous strength and ductility, the cryorolled sheets were then subjected to aged. In this regard the produced samples were then resistance spot welded with different welding parameters, including welding current 60 to 105 KA, electrode force of 3 KN, and welding time of 0.1 s. The highest tensile shear peak load was obtained through welding with 95 KA current.
M.r. Borhani, S.r. Shoja Razavi, F. Kermani, M. Erfan Manesh, S.m. Barekat, H. Naderi Samani, M. Shahsavari,
Volume 8, Issue 2 (Journal OF Welding Science and Technology 2023)
Abstract
The purpose of this research is to laser cladding of stellite6 and stainless steel 17-4PH powders on the substrate of stainless steel 17-4PH, and investigate its solidification microstructure. The results showed that the microstructure of the stellite6 cladding has a cobalt solid solution ground phase with an FCC structure and Cr7C3 and Cr23C6 carbides. Also, the values of the primary dendrite distance and the distance of the secondary dendrite arm have decreased by moving away from the interface; The reason for this is related to the difference in the cooling rate in different parts of the coating. The microstructure of 17-4PH stainless steel coating includes martensitic, ferritic, and austenitic phases; Due to the same chemical composition of the substrate and the cladding, the weight percentage of elements such as iron, nickel, chromium, and copper did not change from the cladding to the interface. It indicates the uniformity of the chemical composition of the cladding and the substrate. The calculated microhardness for the cladding of stellite6, the substrate and the cladding of stainless steel 7-4PH is about 480, 350, and 350 respectively. The reason for the higher microhardness of the cladding is the presence of chromium carbides (Cr7C3 and Cr23C6) formed in the cobalt field and the cobalt solid solution field of the cladding.
