水冷工艺对Q420qE桥梁钢组织与力学性能的影响

Effect of Water Cooling Process on Microstructure and Mechanical Properties of Q420qE Bridge Steel

研究了水冷工艺对Q420qE钢板组织和力学性能的影响。结果表明:通过控制水冷工艺可以得到完全的贝氏体组织或铁素体+贝氏体的混合组织,并且可以控制各相的比例和组织的粗细程度。降低开始冷却温度可以产生先析出铁素体,能够有效降低屈强比;增大冷速可以明显细化铁素体和贝氏体,使得屈强比升高,冲击韧性提高;降低终冷温度先析出铁素体形貌没有明显差异,针状铁素体和贝氏体含量增加,屈服强度无明显变化,抗拉强度升高,屈强比降低。

The effects of the water cooling process on the microstructure and mechanical properties of Q420qE bridge steel were studied. The results indicate that by controlling the water cooling process, a complete bainite structure or the mixed structure of ferrite +bainite can be obtained, and the proportion of each phase and the thickness of the structure can be controlled. Decreasing the initial cooling temperature can produce precipitation ferrite, which can effectively reduce the yield ratio. Increasing the cooling rate can significantly refine the ferrite and bainite, increasing yield ratio, and increasing the impact toughness. There is no obvious difference in the morphology of the first precipitation ferrite when the final cooling temperature is decreased, the content of acicular ferrite and bainite increases, and the yield strength does not change significantly, the tensile strength increases, and the yield strength ratio decreases.