Abstract: The CCT(continuous cooling transformation)curves,microstructure transformation and mechanical prop-erties of 16 mm plate of ultra-low carbon bainite steel DB800 (%:0.058C,0.29Mo,0.05Nb,0.08V,0.02Ti, 0.001B) melted by 50 kg vacuum induction furnace and control-rolled and cooled have been measured and studied. Results show that the structure of test steel water cooled with cooling rate 10 ℃/s is globular bainite which presents lath morphology by TEM observation; the test steel has excellent comprehensive mechanical properties:tensile strength-885 MPa,yield strength-733 MPa,elongation- 15.2%,longitudinal impact energy at -20 ℃-46 J and nice cold-bending property.

Key words: Ultra-Low Carbon Bainite Steel DB800, Microstructure, Mechanical Properties

摘要： 测试和研究了50 kg真空感应炉熔炼、控轧控冷16 mm超低碳贝氏体DB800(%:0.058C、0.29Mo、0.05Nb、0.08V、0.02Ti、0.001B)板材的连续冷却转变(CCT)曲线、组织转变和力学性能。结果表明,该试验钢种在冷却速率约为10℃/s的水冷条件下的组织为粒状贝氏体(TEM下呈板条状形貌)。试验钢种具有优良的综合力学性能:抗拉强度885 MPa,屈服强度733 MPa,伸长率15.2%,-20℃纵向冲击韧性值46 J和极优的冷弯性能。

关键词: 超低碳贝氏体钢DB800, 显微组织, 力学性能