Yong Steel Group, an iron and steel producer in China, has managed to extend the service life of its pulverised coal injection (PCI) lance tubes – one of the most important blast furnace components – from one month to one year by replacing standard grade tubing with Sandvik 253 MA.
Sandvik 253 MA is an austenitic chromium-nickel steel that is designed for excellent high temperature oxidation resistance and carburisation corrosion resistance and good high temperature strength. These properties have proven key to reducing the cost of PCI through improved energy efficiency and production consistency.
Photo courtesy of Sandvik
“Worn out or bent lance tubes may cause the shutdown of the blast furnace and result in huge economic losses. This can be avoided with Sandvik 253 MA, which has higher creep rupture strength, abrasion resistance and better corrosion resistance at higher temperatures. The grade has improved high temperature strength and structural stability to give added safety benefits”, said David Zhou, Technical Marketing Specialist, Sandvik.
Whereas standard grades last from between one to two months, or for as little as two-to-three weeks, with standard AISI 304L, Sandvik 253 MA can increase PCI lance tube life by more than three times. It has been widely used abroad to replace familiar PCI lance tubes manufactured from conventional materials such as 310S, TP 321H and 316L.
