Hot cracking in duplex stainless steel weldments - a review

Due to primary ferritic solidification, the duplex stainless steels are generally considered resistant to solidification cracking. Although very few publications are available on any form of hot cracking of duplex grades, these alloys are not immune to the phenomenon. This review paper gives an introduction to solidification cracking in stainless steel welds, the weldability of the duplex grades, and possible circumstances where solidification cracking may occur. As the duplex alloys are increasingly used in applications where heavy-wall material is welded under highly restrained conditions, the risk for hot cracking also increases. Ways to detect and inspect cracks are discussed. Particular focus is placed on the flux-cored arc welding (FCAW) process where high welding speeds can be reached and especially when using ceramic backing for the root pass. Different compositions and slag concepts by various manufactures for different wires are debated as these can have a considerable effect on the susceptibility.

Automated summary

This article introduces the issue of solidification cracking in stainless steel welding, the weldability of duplex stainless steel, and the possible circumstances where solidification cracking may occur. The methods for detecting and inspecting cracks are discussed, with a particular focus on the flux-cored arc welding process and the effect of different compositions of wires on crack susceptibility.