Austenite-ferrite dual-phase heat-resistant steel as well as preparation method and application thereof

The invention aims to solve the technical problems of the existing grate plate material of the chain grate machine, and provides austenite-ferrite dual-phase heat-resistant steel as well as a preparation method and application of the austenite-ferrite dual-phase heat-resistant steel. The heat-resistant steel comprises the following chemical components in percentage by mass: 0.30-0.40% of C; 0.5 to 1.0 percent of Si; mn: 3.0 to 4.0%; cr: 24.0% to 28.0%; ni: 3.0 to 4.5%; 0.20% to 0.24% of N; 0.1% to 0.15% of Nb; p is less than or equal to 0.035%; s is less than or equal to 0.035%, and the balance is Fe and inevitable impurities. According to the biphase heat-resistant steel, the high-temperature mechanical property and the high-temperature oxidation resistance are greatly improved, and the biphase heat-resistant steel can be stably used at the temperature of 100-1000 DEG C. 本发明的目的是为了解决现有链篦机篦板材料存在的技术问题，提供了一种奥氏体-铁素体双相耐热钢及其制备方法和应用。耐热钢各化学组分质量百分比为：C：0.30～0.40％；Si：0.5～1.0％；Mn：3.0～4.0％；Cr：24.0～28.0％；Ni：3.0～4.5％；N：0.20