The Effect of Welding Parameters on the Corrosion Resistance of Austenitic Stainless Steel

Abstract

Electricity produced in power plants is essential in our everyday life. In general, the energy transfer takes place after processing the energy source in boilers or steam generators. Steam is generated through this process, that operates the turbines and they generate electricity through the generators. As such equipment operates in a high pressure, corrosive and high temperature environment, these circumstances may damage the tubes in the heat exchangers. Our research examines the potential of corrosion of heat exchanger tubes after welding. The typical corrosion process is pitting. The corrosion resistance of stainless steel depends on a protective, passive film formed on the surface of the steel exposed to the service environment. The use of fusion welding for fabrication leads to local variations in the chemical composition inside the material, which may significantly alter the stability of the passive layer and hence the corrosion behavior. The impact of welding parameters (shielding gas, amperage) was examined on corrosion resistance of X6CrNiTi18-10 austenitic stainless steel. The corrosion test was performed according to ASTM G48 standard. The weight loss was measured in Fe(III)-chloride solution by the first corrosion test. The results showed that the corrosion resistance of stainless steel was better at 50 A and 10 l/min welding parameters. During the second test, a potentiodynamic corrosion test was made, and the potentiodynamic curve was measured in 9% saline solution. In this solution, the stainless steel had a better corrosion property because it was measured in a less aggressive medium.