研究了不同热处理工艺对热轧超低碳中锰钢80 mm特厚板组织与性能的影响。在线淬火态钢板分别进行了回火和离线调质处理。结果表明,特厚板经离线调质后厚度方向1/2和1/4位置的显微组织较回火后的显著细化,形成了回火马氏体和逆转变奥氏体。离线调质态特厚板的屈服强度≥700 MPa,屈强比0.83,伸长率≥35%,-60℃冲击吸收能量≥125 J,获得了优异的强韧性匹配,而且具有较高的厚度方向组织性能均匀性,综合力学性能满足FH690级别要求。 The effects of different heat treatment processes on microstructures and properties of ultra-low carbon medium manganese steel 80 mm thick hot-rolled plate were investigated. On-line quenched steel were tempered and off-line quenched and tempered. The results show that the microstructures of 1/2 and 1/4 of the thickness direction after quenched and tempered are significantly thinned after tempering, forming tempered martensite and retrograded austenite. The yield strength of off-line quenched and tempered plate is ≥700 MPa, the yield ratio is 0.83, the elongation is ≥35%, the shock absorption energy is ≥125 J at -60 ℃, which achieves excellent toughness matching and high thickness Direction of organizational performance uniformity, mechanical properties to meet the FH690 level requirements.