利用TMCP开发F550高强度船板钢的实验研究

F550 High Strength Plate Steel for Shipbuilding Produced by TMCP

使用Gleeble 3800热模拟实验机研究了一种低C微合金SiMnCrNiMo钢的奥氏体连续冷却相变(CCT)行为,使用辊径750mm的二辊可逆实验轧机进行了系列TMCP实验,开发出F550高强度船板。生产F550船板的TMCP工艺为:在奥氏体再结晶区和未再结晶区进行两阶段轧制,精轧温度800～820℃,精轧压下率67%,轧后以14～18℃/s的速率冷却至350～500℃。钢板的显微组织为细密贝氏体,其屈服强度大于590MPa,抗拉强度大于700MPa,-60℃下Charpy冲击吸收能量高于230J。

Continuous cooling transformation （CCT） behavior of a low carbon micro-alloyed SiMn- CrNiMo heavy plate steel was investigated employing a Gleeble 3800 thermo-mechanical simulator. A series of thermo-mechanical control process （TMCP） operations were conducted employing a two high reversing pilot rolling mill with accelerated cooling system. F550 shipbuilding plates with yield strength （YS） greater than 590MPa and average Charpy V Notch （CVN） energy at --60~C higher than 230J were successfully developed by the TMCP. Finish rolling at 800-820~C with reduction rate 67 ~ followed by accelerated cooling interrupted at 350-500~C is essential to achieve fine bainite micro- structure and superior properties in the F550 plates.