What would four times longer tube life do for your recuperator efficiency?
Sandvik 253 MA* proved to be the right steel grade for use in recuperators and played a central role when a Turkish steel manufacturer set out to reduce energy consumption and increase equipment service life.
One of Turkey's largest steel producers wanted to reduce energy consumption, prolong the service life of recuperators and simultaneously increase production. To make it possible, the recuperators, essential for recovering outgoing heat from the furnaces, had to be able to run at higher temperatures. The challenge was to find a steel grade that could perform effectively at higher temperature levels.
The Sandvik solution
After contacts with material experts from Sandvik, the customer decided to install tubes in grade Sandvik 253 MA into four recuperators. Sandvik 253 MA is a heat resistant, austenitic chromium-nickel steel characterized by very good resistance to isothermal and cyclic oxidation, as well as structural stability at high temperatures. It includes the rare earth metal cerium, making it oxidation resistant and perfectly suited to a hot recuperator environment.
The changeover to tubes in Sandvik 253 MA made it possible to run the recuperators at higher temperatures and save substantially on energy consumption. At the same time, a production increase of 60% has been achieved. The old conventional high-temperature tubes in the recuperators had a service life of about 2 years. The tubes in Sandvik 253 MA have, so far, been running for 8 years without problems.
* 253 MA is a trademark owned by Outokumpu OY.