Austenitic stainless steel S31660 (1Cr18Ni12Mo2Ti) is a high quality austenitic stainless steel developed by AFFILOX, a subsidiary of Nippon Steel Corporation. It has high strength, excellent corrosion resistance and good weldability. The chemical composition of S31660 is summarized as follows (wt. %):
C 0.07-0.14
Si ≤ 1.00
Mn ≤ 2.00
P ≤ 0.035
S ≤ 0.030
Cr 17.0-19.0
Ni 11.0-14.0
Mo 2.0-2.5
Ti 0.5-1.00
The corrosion resistance of S31660 is due to its high Chromium content and its inherent resistance to sensitization. Sensitization is the formation of chromium carbide deposits in the grain boundaries due to changing microstructure when exposed to temperatures over 550°C. These carbide deposits can significantly reduce the corrosion resistance of stainless steel as they reduce the amount of chromium available thus allowing chromium depleted regions in the grain boundaries which can lead to intergranular corrosion.
At the same time, S31660 has a reasonable yield strength at 450MPa and a tensile strength at 600MPa. As the alloy has a low carbon content, it has good weldability, meaning that welding processes can be used to join it easily. The main thing to consider when welding S31660 is that, in comparison to other stainless steels, it requires a higher interpass temperature due to its higher heat input of 420 J/cm compared to typical heat requirements of only 320-360 J/cm for 316L stainless steel.
Due to its good strength, corrosion resistance and weldability, S31660 is suitable for use in many ocean and coastal environments. It is also resistant to various applications, such as acid and alkali, and is therefore suitable for applications involving water, seawater, and petroleum. It’s excellent corrosion resistance makes it an ideal choice for chemical processing and offshore oil and gas applications. It is also an excellent choice for food industry applications due to its non-toxicity, which makes it safe to use in contact with food. Furthermore, its use in decorative architectural applications such as handrails and balustrades is becoming increasingly popular due to its excellent aesthetics and low maintenance requirements.
Overall, Austenitic stainless steel S31660 (1Cr18Ni12Mo2Ti) is an excellent stainless steel for many applications due to its high strength, excellent corrosion resistance, good weldability and low carbon content. With its wide range of uses, from building materials to the food industry and from offshore oil and gas applications to decorative architectural applications, S31660 is becoming increasingly popular and gaining popularity in many industries.
