Duplex steels provide resistance to embrittlement

22 February 2021

Researchers from Sandvik and the Royal Institute of Technology (KTH) in Stockholm used high-energy X-rays at the Swedish Material Science beamline to find out why their steels are more resistant to hydrogen embrittlement than competitors’ steels. 

One of the challenges in offshore environments is exposure to hydrogen, which makes steels brittle.

Researchers have since worked to develop steels that are more resistant to hydrogen embrittlement. Such resistance to embrittlement was a key aspect of duplex steels developed by Sandvik.

Researchers from Sandvik and KTH exposed the steel samples to hydrogen and placed these steels under stress – and studied how hydrogen rapidly moves within and interacts with the steel, as well as how the steel’s internal structure evolved.

Duplex stainless steels consist of two phases: the body-centered-cubic (bcc) phase and the face-centered-cubic (fcc) phase. Both fcc and bcc phases are distributed in a complex pattern within the steels.

The coordinated response of the two phases hinders the initiation of micro-cracks, thus providing high resistance to embrittlement.