Investigation on Metallurgical Properties and Corrosion Resistance of Duplex Stainless Steel with and Without Heat Treatment Exposed to Marine Environment

Abstract

Duplex stainless steel has proved to be the most satisfactory materials for marine and saline applications due to its superior mechanical properties and corrosion resistance with good erosion and wear resistance. However, the greatest drawback with conventional stainless steel is susceptibility to localized corrosion in chloride-containing aqueous solutions which limits their use in seawater systems. Corrosion of a material leads to a gradual deterioration of its properties until it fails to fulfill its purpose and necessities to be replaced. DSS exhibits higher resistance to stress corrosion cracking and it has higher strength than austenitic stainless steel. DSS has equal phase balance of about identical quantities of ferrite and austenite. It has assorted microstructure consisting of ferrite (BCC) and austenite (FCC) phases. The mechanical and corrosion properties of stainless steels can be studied in corrosive environment with the effect of heat treatment and investigation of changes in microstructure which influence on mechanical and corrosive property. To study the behavior of DSS under the action of corrosive environments. Precipitation of secondary phases in DSS which led to improve the some mechanical properties and a drastic reduction in its corrosion resistance. Another factor which is responsible for the change in the ferrite / austenite ratio where the corrosion occurred preferentially in the ferrite phase of DSS 2205. newlineThis study presents the systematic approach to examine the mechanical and corrosion behaviour of plain DSS and the consequence of heat treatment at 1050°C and different quenching medium like air, water and furnace on the morphology, mechanical properties and corrosion resistance on the DSS. Examine the effect of various notches and heat treatment with different quenching medium on impact toughness of DSS 2205. Tensile test and micro hardness is observed for with and without heat treatment in various cooling medium. For observed the corrosion behaviour of the DSS 2205, specimens are te