CORROSION RESISTANCE :

In most of the corrosive solutions, alloy UR™ 28 is more corrosion resistant than alloy UR™ 904L (N08904). The alloy is extensively used in phosphoric acid applications and some sulphuric solutions.
Alloy UR™ 28 may also be used in caustic solutions since its molybdenum content remains low comparing with the nickel and chromium additions.
High chromium and moderate molybdenum additions contribute to improve the local corrosion resistance of UR™ 28 alloy. The grade performs much better than alloy 825 and better than alloy N08904 (UR™ 904L) in acidic chloride containing solutions.
The high nickel and molybdenum contents give UR™ 28 an excellent resistance to stress corrosion cracking phenomena. This is particularly the case for high temperature applications (140 - 400°C = 284 - 752°F) and chloride containing environments.
UR™ 28 is particularly well designed for sour gas applications and has been successfully tested at 230°C (446°F) with 3 bars H2S and 50 bar CO2 with high chloride levels.

APPLICATIONS :

UR™ 28 alloy has been used with success in the following applications :
• Production, concentration and use of phosphoric acid reactors tanks, impellers, piping systems, cyclone evaporators, surface coolers, circulation pumps, agitators, superphosphoric acid storage, shell/tubes for heat exchangers
• Production and use of sulphuric acid: heating equipment, reactor tanks, agitators, inlet pipe in reactors...
• Oil and gas production : sour gas application, tubing, separators...
• Several offshore platform equipment
• Chemical industry (acetic acid, vinyl chlorides)