Alleima® 353 MA* is an austenitic, chromium-nickel stainless steel contributing to longer tube life and reduced maintenance in a wide range of high-temperature applications.
Alloyed with nitrogen and rare earth metals (REM), Alleima® 353 MA is characterized by high performance in oxidizing, carburizing and nitriding environments.
Finned tubes for ethylene furnaces
The high resistance against carburization makes Alleima® 353 MA especially suited for finned tubes in ethylene furnaces. Combined with good oxidation properties at high temperatures, the use of Alleima® 353 MA finned tubes can contribute to longer production runs before decoking.
High creep strength
Alleima® 353 MA exhibits very good creep properties at high temperature and its creep strength meets the design requirements of steam cracking furnace tubes. The material's high content of nitrogen contributes to the high temperature strength.
Comparing Alleima® 353 MA with cast alloys, it can be seen that the creep strength is not as high. The additional strength in cast material is, however, normally not utilized, since the limiting factor for tube life is carburization and time between decoking.
Fabrication
The weldability of Alleima® 353 MA is good. Suitable welding methods are manual metal-arc (MMA) welding with covered electrodes and gas shielded arc welding with the TIG and MIG methods as first choice. Preheating and post-weld heat treatments are normally not necessary.good