High Temperature Corrosion Properties of Chromized Austenitic Stainless Steel

Abstract

Studies on the high temperature corrosion behavior of SUS347H in oil fired boiler environments were carried out by laboratory corrosion tests and examinations of the served tube.
It was observed that chromized SUS347H showed a better corrosion resistance than 18Cr-8Ni austenitic stainless steels when they were precoated with 20/80%V₂O₅-80/20%Na₂SO₄ synthetic ash and heated at 600800°C for 5100 h in 1%SO₂-5%O₂-15%CO₂-bal. N₂ gas. Chroinized SUS347H reheater tube, which served for about 10 000 h in an oil fired boiler, did not show a significant thickness loss. Cr₂O₃ scale formed on chromized surface increased high temperature corrosion resistance in oil fired boiler.