The effect of nitrogen and heat treatment on the microstructure and tensile properties of 25Cr-7Ni-1.5Mo-3W-xN Duplex stainless steel castings

The effects of nitrogen content and solution treatment temperature on the microstructure and tensile properties of 25Cr-7Ni-1.5Mo-3W-xN Duplex stainless steel (DSS) castings were investigated. An increase of nitrogen decreases the ferrite volume fraction and also can cause gas defects and change the solidification mode from ferrite single phase to ferrite-austenite mode. An increase of heat treating temperature increases the ferrite volume fraction, which decreases the tensile strength and the elongation but increases the yield strength almost linearly. (C) 2001 Elsevier Science B.V. All rights reserved.