About this Abstract |
Meeting |
Advances in Welding and Additive Manufacturing Research 2022
|
Symposium
|
Advances in Welding and Additive Manufacturing Research 2022
|
Presentation Title |
Varestraint Weldability Testing of Sanicro 25 and 310S Stainless Steel |
Author(s) |
Mikael Magnus Johansson, Peter Stenvall, Maria Asuncion Valiente Bermejo, Joel Andersson |
On-Site Speaker (Planned) |
Mikael Magnus Johansson |
Abstract Scope |
Sandvik Sanicro 25 (UNS S31035) is an advanced high temperature austenitic stainless steel that potentially can be used in super-heaters and reheaters in the next generation of advanced ultra-super critical power plants. The material possesses both high creep strength and good corrosion resistance at temperatures up to 700°C. Its high temperature properties are positioned between other commercially available high temperature austenitic stainless steels and nickel-based alloys. It is, however, well known that an austenitic solidification mode combined with a fully austenitic microstructure exacerbate susceptibility towards hot cracking. The problem increases for thick-walled material in multipass welding and could compromise the integrity of the welded component.
Varestraint weldability testing can be used to investigate susceptibility towards hot cracking of materials. In this paper, Varestraint test results are evaluated for base material of Sanicro 25 and are compared to those of the well-known and well characterized grade 310S (UNS S31008). The more creep resistant alloy, Sanicro 25, is metallurgically more complex than 310S and has additions of several alloying elements to improve its high temperature properties. It benefits from both solid solution hardening as well as precipitation hardening. This investigation therefore attempts, based on the Varestraint weldability test and thermodynamical calculations, to understand if there are any differences in cracking mechanisms between these two grades due to the additional alloying elements used in Sanicro 25. Results from Varestraint testing and crack type investigations will be presented and discussed in some detail. It is shown that hot cracking susceptibility of Sanicro 25 is only slightly higher than that of 310S despite the more complex metallurgy. Weldability of the two alloys is therefore judged to be comparable making the newer alloy well suited also for critical applications. |
Proceedings Inclusion? |
Undecided |