CORROSION OF STEEL WELDMENT

Abstract

Austenitic stainless steels find important and variety application such as construction materials in chemical and petrochemical industries, civil engineering, marine, ship building, oil and gas industry. SS 316 (stainless steel 316) is one of most popular austenitic stainless steel used for these applications. Welding of stainless steels modify the constancy of the passive layer causes the corrosion issue arises when it is exposed to the industrial environment. This work is aim to determine the corrosion behavior of welded SS 316 steel under different welding parameters. Electrochemical tests (Open Circuit Potential, Linear Polarization, Cyclic Polarization and electrochemical impedance spectroscopy) are used in order to obtain the corrosion behavior of SS 316 steel. Nine welding parameters are used in this project and from every welding parameter two samples are used for investigation; welded cut section at fusion zone and cut section at HAZ (heat affected zone) of SS 316 with one base metal sample. Temperature and pH of the 3.5% NaCl solution are the parameters that involve in determining the corrosivity of the welded SS 316.