| 摘要 |
PURPOSE:To obtain a heat-resistant cast steel combining castability, productivity and machinability comparable to those of conventional heat-resistant cast iron with heat resistance comparable to that of conventional high-alloy heat-resistant cast iron by carrying out regulation of composition and annealing treatment. CONSTITUTION:The heat-resistant cast steel has a composition consisting of, by weight, 0.5-2.3% C, 2-4% Si, 0.2-0.7% Mn, <0.05% P, <0.1% S, 5-10% Cr, 0.5-2% Al and the balance Fe, which is subjected to casting, austenitizing treatment at 900-750 deg.C for >=0.5hr and then annealing treatment comprising furnace cooling down to 680-750 deg.C, holding at 680-750 deg.C for >=0.5hr and cooling. In this way, precipitated carbides in a graphite-free ferritic matrix structure are formed into dendritic primary carbides and finely dispersed secondary carbides. |
