Abstract: The tested steel 32CrNiMoNb (/% ： 0.32C, 0. 30Si, 0. 30Mn, 0.012P, 0. 004S, 1.25Cr, 1.20Ni, 0. 36Mo, 0. 05Nb) is melted by a 200 kg vacuum induction furnace and cast to 130 mm x 135 mm billet. And in laboratory the billet is rolled to 12 mm plate by a 550mm medium-heavy mill using two stage controlling rolling and cooling and direct- quenching process. The effect of beginning rolling temperature (950°C and 1000°C ),finishing rolling temperature (900°C and 950°C ) and direct-quenching end cooling temperature (150~350 °C ) at second stage on structure and mechanical properties of tested steel has been tested. Results show that at second stage with beginning rolling at (950 土 10)°C , finishing rolling at (900 ± 10)°C and direct-quenching end cooling temperature (250 土 10)°C , the matching of mechanical properties (R_p0.2 - 1 515 MPa, R_m- 1 805 MPa, A- 8% and at -40 °C impact energy KV2- 24 J) and bending performance (180° ) of plate, structure (fine martensite) and precipitated phase ( NbCN) is best.

摘要： 试验用32CrNiMoNb钢（/%:0.32C,0.30Si,0.30Mn,0.012P,0.004S,1.25Cr,1.20Ni,0.36Mo,0.05Nb）经200 kg真空感应炉熔炼,铸成135 mm×135 mm铸坯。在实验室550 mm中厚板轧机,采用两阶段控制轧制加直接淬火工艺生产12 mm钢板。试验了第二阶段开轧温度（950℃和1 000℃）、终轧温度（900℃和950℃）、直接淬火终冷温度（150350℃）对试验钢力学性能和组织等的影响。结果表明,第二阶段开轧温度（950±10）℃、终轧温度（900±10）℃、直接淬火终冷温度（250±10）℃,钢板的力学性能(R_p0.2 1515 MPa,R_m 1805 MPa,A8%,-40℃K_v2冲击功24 J)、弯曲性能（180°）、组织（细小马氏体）和析出相（NbCN）达到了最佳匹配。