EH47止裂钢奥氏体连续冷却转变行为

Continuous Cooling Transformation Behavior of Austenite in EH47 Crack-Resistant Steel

采用Gleeble-3800热模拟实验机测定了Nb-Ti-V微合金化0.04~0.08C-0.6~1.2Ni-0.1~0.5Cr-0.1~0.5Cu大型集装箱船用EH47止裂钢在0.05~50℃/s冷速下连续冷却转变的膨胀曲线,结合光学显微镜的微观组织观察,得出了该钢奥氏体连续冷却转变过程中的CCT曲线;研究了EH47止裂钢连续冷却转变产物的组织形态和显微硬度。结果表明,EH47止裂钢在0.05~50℃/s冷却速率下的组织主要由铁素体+珠光体、针状铁素体+贝氏体组成,即使冷却速度达到了50℃/s,组织中仍然未见马氏体出现。

By measuring the dilatometric curves of Nb-Ti-V micro-alloying 0.04 ~0.08 C-0.6 ~1.2 Ni-0.1 ~0.5 Cr-0.1 ~0.5 Cu crack-resistant steel EH47 for large container ship with cooling rate of 0.05 ~50 ℃/s on a Gleeble-3800 thermo-mechanical simulator,and combining with metallographic analysis,a CCT diagram of austenite continuous cooling transformation is obtained.And the microstructure and hardness of the continuous cooling transformation occurring in EH47 crack-resistant steel are investigated.The results show that the microstructure of EH47 crack-resistant steel at 0.05~50 ℃/s cooling rate consists of ferrite+pearlite and accicular ferrite+bainite.Even the cooling rate as high as 50 ℃/s,no martensite occurs in the microstructure.