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
