Alloyed with nitrogen and rare earth metals (REM), Sandvik 353 MA is characterized by high performance in oxidizing, carburizing and nitriding environments.

¹⁾ To cerium should be added the quantity of other rare earth metals because the addition takes the form of misch metal containing about 50% Ce.

Finned tubes for ethylene furnaces

The high resistance against carburization makes Sandvik 353 MA specially suited for finned tubes in ethylene furnaces. Combined with good oxidation properties at high temperature, the use of Sandvik 353 MA finned tubes can contribute to longer production runs before decoking.

Read more about the oxidation and carburization properties of Sandvik 353 MA

High creep strength

Sandvik 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 Sandvik 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 Sandvik 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.

Compared with cast alloys, tubes in wrought alloys such as Sandvik 353 MA, can be produced in longer lengths. The longer length has cost advantages, since less welding is required during fabrication of furnace coils. Wrought materials are also more ductile at room temperature. Consequently, welding is easier, especially after service exposure. Both cold bending and hot bending are possible depending on tube dimensions and the bending radius.

*353 MA is a trademark owned by Outokumpu OY.