| 摘要 |
PURPOSE:To allow a steel to show superior corrosion resistance in an environment in which an exhaust gas economizer is used by specifying the amounts of C, Si, Mn, Cr, Cu, Ni and Mo in the steel. CONSTITUTION:The composition of a steel is composed of, by weight, 0.03-0.25% C, <=1.0% Si, <=2.0% Mn, 0.3-2.5% Cr, <=1.0% Cu, <=1.0% Ni, <=1.5% Mo and the balance Fe with impurities. In the composition, Mo is an element required essentially when a soot blower is used and exposed to shot blasting so as to prevent reduction in thermal efficiency by the sticking of combustion residue, and it is preferable that Mo is added by >=about 0.25%. The steel is suitable for use as a material for an exhaust gas economizer, has superior corrosion resistance, is easily welded and causes hardly electric corrosion. The steel can be also used as a material for a boiler, a gas heater, a heat exchanger, etc. |
