Hot Cracking Susceptibility in Duplex Stainless Steel Welds

摘要

Duplex stainless steels (DSSs) are structural materials that exhibit high yield strength-toughness combination and superior localized corrosion resistance when compared with other stainless steels. However,Duplex stainless steel undergo microstructural changes during welding that may have an impact on their mechanical and corrosion properties. The solidification microstructure of the heat affected zone (HAZ) in the weld does not have nearly equal amounts of a and y phase as the parent metal. Thus,the mechanical property and corrosion resistance of the weldment is degraded because there is much less y in the fusion zone. Due to the occurrence of these problems in arc welding,the application of laser welding is expected in recent years. Laser beam welding (LBW) also leads to low distortion in the welded structure,even for alloys with a high thermal expansion coefficient and low thermal conductivity. These reasons explain why the LBW process has been frequently preferred for welding fabrication in several industrial fields. However,there are still many studies on the evaluation of corrosion resistance,strength,and toughness,mainly about arc welding,and there are not many studies on laser welding.