Showing 2 results for Abedi Chermahini
Hossein Abedi Chermahini, Mohammad Mahdi Piran, Ali Akbar Esmaeili Chamgordani, Masoud Atapour,
Volume 9, Issue 2 (Journal OF Welding Science and Technology 2024)
Abstract
In this research, the mechanical properties and microstructure of L316 grade stainless steel sheets welded using the resistance spot welding method with a copper interlayer were investigated. In this regard, two types Connection were considered: one without the interlayer and the other with the copper interlayer, connected at different currents. To select the optimal current for both types of connections, tensile tests were initially conducted. Following that, microstructural examinations, microhardness tests, elemental evaluations, and failure mode analyses were performed on the optimized samples. according to the results obtained, increasing the electric current raised the input heat in the weld pool to an appropriate level, improving the microstructural and mechanical properties of the weld region. Additionally, due to the optimal electric current in both samples "with and without" the interlayer, both samples experienced interfacial failure, indicating high strength at their joint and weld points. Changes in chemical composition across different weld areas were minimal, and element distribution was reported to be uniform throughout all regions. The highest hardness was observed from the base metal towards the center of the weld in the order of weld area > base metal > heat-affected zone, which corresponded with results from microstructural examinations.
Hossein Abedi Chermahini, Masoud Atapour, Mojtaba Esmail Zadeh,
Volume 9, Issue 2 (Journal OF Welding Science and Technology 2024)
Abstract
Nowadays, to achieve the simultaneous properties of multiple alloys in important applications such as automotive and aerospace, the use of surface coating methods is common. Coating through welding (cladding) is one of the widely used methods for surface modification of metal parts and sheets in the industry. Low-alloy steel AH36 is one of the steels used in shipbuilding, known for its toughness and good corrosion resistance, gaining significant recognition among other steels used in this industry. In this research, to improve the corrosion properties of this steel, the cladding process was performed using Gas Tungsten Arc Welding (GTAW) with copper/nickel filler wire. Two samples from coated and uncoated sections, termed base metal and weld metal, were prepared and subjected to microstructural and corrosion investigations. The results indicated an increase in grain size in the heat-affected zone of the weld metal sample, leading to a reduction in mechanical properties. The pitting potential for both base and weld metals was reported as -1.7 V and -0.5 V, respectively, indicating a greater capability of the weld metal for pitting repair in case of stable pit formation. The presence of only a single semicircle in the Nyquist plot indicates a single-loop equivalent circuit and confirms the absence of a passive layer. Additionally, resistance to pitting and charge transfer resistance was reported to be higher in the base metal compared to the weld metal
