Abstract: The hot compression test on 4>5 mm x 86 mm test specimen cut from 80 mm hot-rolled plate of steel EH460 (/% ： 0.07C, 0.39Si, 1.76Mn, 0.34Ni, 0.36Cu, 0.02〜0.05Nb, 0.05~0.10V, ≤0.02Ti, 0.008Als) with 10℃/s heating to 1200 ℃for 5 min austenizing then with 10°C/s cooling to 830 °C and with strain rate 1 s^-1 , deformation 30% at 830°C,then cooling to ambient temperature with 1~30°C/s has been carried out by using a Gleeble-3800 thermal simulation testing machine. And the dynamic continuous cooling transfonnation (CCT) curves of tested steel EH460 is obtained by dilation-temperature curves combined with structure at different cooling rate and using Origin software. Results show that with cooling rate less than 3 °C/s the structure of steel EH460 is ferrite + minor bainite, with cooling rate 5~10°C/s the structure is bainite + minor ferrite and with cooling rate more than 20 °C/s the structure is mainly lath bainite with little granular bainite ； with cooling rate increasing from 1 °C/s to 30 °C/s the HV hardness value of the steel increases form 246 to 274.

Key words: Hull Structure Steel EH460, Phase Transformation, Cooling Rate, CCT Curves

摘要： 通过Gleeble-3800热模机将EH460钢80 mm热轧板（/%:0.07C，0.39Si，1.76Mn，0.34Ni，0.36Cu，0.02~0.05Nb，0.05~0.10V，≤0.02Ti，0.008A1）切取的φ5 mm×86 mm试样以10℃/s加热至1200℃ 5 min奥氏体化,然后以10℃/s冷却至830℃，并在830℃以变形速率1 s^-1，进行30%的热压缩变形试验，并以130℃/s冷却到室温。通过膨胀量-温度曲线,结合不同冷却速率下的组织，利用Qrigin软件得出EH460钢的动态连续冷却转变曲线。结果表明，当冷却速率小于3℃/s时，EH460钢的组织为铁素体+少量贝氏体；当冷却速率为5~10℃/s时，组织为贝氏体+少量铁素体；当冷却速率大于20℃/s时，组织以板条贝氏体为主，并含少量粒状贝氏体；当冷却速率从1℃/s增加至30℃/s时，该钢HV硬度值由246增加到274。

关键词: EH460船板钢, 相变, 冷却速率, CCT曲线