6.5 percent Silicon Bearing Stainless Steel for Sulfuric Acid Plant

摘要

The studies on hot workability of 6.5 percent Si-0.01 percent Pd bearing stainless steels were carried out in order to develop a new corrosion-resistant steel used in sulfuric acid environment with 98 approx percent concentration at up to 200 deg C. Problems on the hot workability are a low temperature of zero ductility due to partial melting of Si-Ni rich intermetallic-compounds and a poor ductility under 950 deg C due to precipitation of Si-Cr rich ones. Alloy design for introducing a small amount of #delta# ferrite (<= 5 percent) make it possible to increase the zero ductility temperature and to improve the ductility under 950 deg C. As the results, the production of the steel plates has become possible on a factory scale.