水电站用800 MPa级低焊接裂纹敏感性高强钢板SX780CF的开发

Development of 800 MPa Low Welding Crack Sensitivity High Strength Steel Plate SX780CF for Hydropower Station

通过设计成分(/%:0.09C,0.15Si,1.15Mn,0.58Ni,0.47Cr,0.44Mo,0.033V,0.022Nb,0.0012B,0.036Al,0.014Ti),控制熔炼分析N含量≤20×10^(-6)冶炼,钢锭最高加热温度≤1200℃轧制、930℃淬火、610℃回火,开发出的60mm厚SX780CF钢板屈服强度780MPa,抗拉强度887MPa,延伸率18%,5%应变250℃时效后-20℃冲击功(KV_(2))203~210 J,满足水电站用800 MPa级低焊接裂纹敏感性高强钢技术要求。

Through the design composition(/%:0.09C,0.15Si,1.15Mn,0.58Ni,0.47Cr,0.44Mo,0.033V,0.022Nb,0.0012B,0.036Al,0.014Ti),the N content of smelting analysis controlled to be≤20×10^(-6)in steel smelting,rolling with ingot maximum heating temperature≤1200℃,and quenching at 930℃and tempering at 610℃,the developed 60 mm SX780CF steel plate has yield strength 780 MPa,tensile strength 887 MPa,elongation 18%and 5%strain 250℃aged-20℃impact energy(KV_(2))203~210 J,which meet the technical requirements of 800 MPa low welding crack sensitivity high strength steel for hydropower station.