Sandvik 2RE10
Seamless tube and pipe

General corrosion
Sandvik 2RE10 was developed to combat corrosion problems in nitric acid service. Thanks to its high chromium and low impurity contents it has considerably better resistance to nitric acid than steel type AISI 304L, as illustrated by the isocorrosion diagram, figure 1. In such applications 2RE10 is far superior to AISI 304L, AISI 321 and AISI 329. The corrosion rates of these grades in 65% nitric acid (Huey test) are compared in figure 2. Sandvik 3R12 is the Sandvik version of AISI 304L (see data sheet S-1823-ENG). Results are presented from tests of solution annealed material (the delivery condition) and also material in a sensitised (650°C for 1h) condition. (AISI 329 was sensitised at 650°C for only 5 min.).


    Figure 1. Isocorrosion diagram for Sandvik 2RE10 and 3R12 (AISI 304L) in a naturally aerated, stagnant solution of nitric acid. The curves represent a corrosion rate of 0.1 mm/year (4 mpy).



      Figure 2. Huey test results for different stainless steels (average values).
      Arrows denote accelerated attack for each period, which indicates material will not perform satisfactorily in service.


Stress corrosion cracking
The higher nickel content makes Sandvik 2RE10 slightly more resistant than conventional austenitic stainless steels, such as AISI 304L.

Intergranular corrosion
Sandvik 2RE10 is highly resistant to intergranular corrosion even after long-term sensitisation. Figure 4 shows the results of Huey testing (boiling in 65% nitric acid for 5x48h) sensitised specimens of 2RE10 and a steel of type AISI 304L. The low tendency for sensitisation is an advantage in complicated welding operations. In delivery testing, by means of the Huey test, the guaranteed maximum corrosion rate for 2RE10 is 0.12 mm/year (5 mpy) in the solution annealed condition, and 0.20 mm/year (8 mpy) after sensitisation at 675°C (1250°F). Even lower values can be guaranteed by agreement in certain cases. Figure 3 demonstrates that sensitisation does not increase the corrosion rate greatly in Huey testing, whereas the corrosion rate for AISI 304L increases significantly.

Pitting corrosion
Sandvik 2RE10 has considerably higher pitting corrosion resistance than AISI 304L and is also superior to AISI 329, as illustrated by figure 4.




      Figure 3. Corrosion curves for Sandvik 2RE10 and AISI 304L obtained from Huey testing after sensitisation at 675°C (1250°F).


      Figure 4. Critical pitting temperature (CPT) for Sandvik 2RE10, AISI 304L and AISI 329 in neutral chloride solutions (potentiostatic determination at
      +300 mV SCE).



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A document from the Sandvik Materials Technology web-site.