2553

These consumables are formulated to align with alloys frequently utilized in castings. The incorporation of copper serves a dual purpose, enhancing corrosion resistance in sulfuric acid environments while also presenting the potential to improve strength and wear resistance. It's important to highlight that, compared to alloys with less than 1% Copper, the as-welded toughness and resistance to pitting in chloride environments may be reduced. The composition is carefully controlled to maintain a minimum Pitting Resistance Equivalent (PRE) of 40, aligning with superduplex alloys for optimal pitting resistance. However, for applications in non-sulfuric acid media, consumables with less than 1% Copper may be preferred, unless post-weld heat treatment (PWHT) is applied. These consumables find applications in pumps, valves, corrosion-resistant and wear-resistant components, as well as process equipment suitable for use in offshore oil and gas industries, pulp and paper, textile industries, and chemical and petrochemical plants.

25%Cr ferritic-austenitic superduplex stainless steels with nominally 25%Cr-8%Ni-3.5%Mo-1.5%Cu-0.2%N.

In the as-welded, or solution annealed condition, the microstructure is an austenite-ferrite duplex with about 25-60% ferrite.

EN W.Nr.: 1.4515 (G-X3CrNiMoCuN 26 6 3), 1.4517 (G-X3CrNiMoCuN 26 6 3 3).
ASTM: A351 & A744 gr. CD4MCu, A890 gr. 1A, A890 gr. 1B.
UNS: S32550, J93370, J93372, S39255+
PROPRIETARY: Ferralium® 255–SD50, 255–SD40 (Langley Alloys), Uranus® 50M, 55, 52N, 52N+, 47N (Industeel), Ferrinox® 255 (Advanced Metals).

Preheating is generally unnecessary for typical fabrication welds, and the interpass temperature is maintained below 150°C. However, for highly restrained welds like castings, implementing a preheat-interpass range of 100-225°C proves advantageous to mitigate the risk of hydrogen cracking. The consumables are primarily designed for use in the solution annealed condition. Castings invariably necessitate solution annealing, and both the electrode and flux-cored wire offer increased toughness and slightly reduced strength after solution annealing. The standard post-weld heat treatment involves heating to 1120°C for about 2-3 hours, followed by water quenching.