Multicomponent Phase Diagram of Lean Duplex Stainless Steel UNS S82441 and Its Application to Evaluate the Microstructure in the Heat Affected Zone

作者：de Pauli Evandro Armini; Schon Claudio Geraldo; Brandi Sergio Duarte^*

来源：Journal of Phase Equilibria and Diffusion, 2017, 38(3): 332-342.

DOI：10.1007/s11669-017-0551-x

• intermetallic phases
• lean duplex stainless steel
• Thermo-calc (R)
• UNS S82441
• welding

Duplex stainless steels are Fe-Cr-Ni-Mo-N alloys with nitrogen replacing some nickel to improve its properties. These steels have a balanced microstructure, which means that ferrite (alpha) and austenite (gamma) are in equal proportions of approximately 50% by volume. These alloys have a tendency to form intermetallic precipitates such as chromium nitrides and sigma phase (sigma), depending on their chemical composition and welding thermal history. Precipitation of these intermetallic phases can impair mechanical and corrosion properties. In addition, material processes such as welding and heat treatment can change the balanced microstructure. The objective of this work was to compare phases formed during heat treatment and welding of duplex stainless steel UNS S82441 with the equilibrium phases predicted by Thermo-calc (R) software. In general, the results showed good agreement between predicted and measured phases, as well as, agreement between the measured volume fraction of austenite in the heat-affected zone and austenite predicted by Thermo-calc (R) software.

• 出版日期2017-6