控轧控冷工艺对钒钛微合金钢组织性能的影响

Effect of Controlled Rolling and Cooling Processing on Microstructures and Properties of V-Ti Microalloy Steels

对低碳微合金V-Ti钢分别进行了不同终轧温度和冷却方式的控制轧制,并对轧后的试样进行了拉伸、冲击实验以及显微组织和透射电镜组织分析.结果表明:不同终轧温度和冷却方式对轧后显微组织及强度有明显的影响,当终轧温度为800±20℃,终冷温度为550±10℃时,实验钢具有贝氏体组织,抗拉强度可以提高到690MPa以上;高温加热+两阶段再结晶轧制(低温终轧830℃)+轧后空冷的加工方式使材料的冲击韧性和塑性提高,但强度下降;高温再结晶终轧(1 000℃)+快速水冷,使得材料碳氮化物析出最多,性能最好,获得优良的强度和韧性.满足了汽车用钢强韧性的要求,为制定合适的生产工艺制度提供了依据,对开发高强度的汽车用钢具有参考价值.

Abstract： Controlled rolling experiments with different finishing rolling temperatures and cooling methods were carried out on V-Ti mieroalloy steel. And the properties of steel were tested by tensile test, impact test, microscopic structure analysis and TEM analysis. The results show that different finishing temperatures and cooling methods have significant effects on microstructures and properties of the rolled steels, when the finish- ing temperature is 800±20℃and the final cooling temperature is 550 ± 10℃ , bainite can be seen, the ten- sile strength is above 690 MPa; the impact toughness and plasticity increase and the strength decreases after high temperature heating and two-stage recrystallization rolling（low temperature finishing rolling 830 ℃ ） and cooling in air after being roiled; the steel has more carbonitride and appropriate strength and ductility after high temperature recrystallization rolling（1 000 ℃ ） and fast water cooling . The results are useful for the de- velopment of high strength automobile strip steel.