Investigation of Microstructure and Mechanical Properties of DSS (2021). 2205 Weld Thick Section for Pressure Vessel Application

Abstract

Number of Industries including marine, oil and gas, pharmaceutical are facing challenges in welding of thick section duplex stainless steel (DSS) to attain desired microstructure and mechanical properties. The DSS is dual phase structure comprising of austenite and ferrite in equal proportion. The present work is aimed to investigate microstructure and mechanical properties of DSS 2205 thick (20 mm) plate weld for pressure vessel by multi-pass shielded metal arc welding using E2209 electrode to maintain heat input 0.5–1.5 kJ/mm. Weldment was tested for ferrite measurement, tensile, impact, hardness and bend test by cutting across the weld. Scanning electron microscope and optical microscope were used to examine microstructures at weld zone and heat affected zone. In microscopic examination, widmanstetten austenite, intra granular austenite and grain boundary austenite were observed in weld zone while partially transformed austenite in heat affected zone.