试验分析了开冷温度、冷却速度和终冷温度对X80HD2管线钢组织和性能的影响，结果表明，在不同开冷温度下，均能得到铁素体和贝氏体双相组织，随开冷温度的降低，铁素体含量增多，M/A含量增加，屈服强度下降，Rt0.5/Rm下降，均匀伸长率降低；随冷却速度提高，贝氏体组织细化，屈服强度增加，Rt0.5/Rm升高，均匀伸长率降低；随终冷温度降低，M/A细化，抗拉强度降低，Rt0.5/Rm升高，加工硬化速率升高，均匀伸长率升高。最佳冷却工艺参数：开冷温度690℃，冷却速度15℃/s，终冷温度400℃。%The influence of cooling temperature, cooling rate and final cooling temperature on the microstructure and properties of X80HD2 pipeline steel were analyzed. The results showed that: in different cold temperatures, the ferrite and bainite dual phase microstructure were obtained. But with decreasing of the cooling temperature, although the ferrite content and the content of M/A increased, the yield strength, Rt0.5/Rm and uniform elongation decreased. With increasing of the cooling rate, the bainite refined, yield strength, Rt0.5/Rm increased, and the uniform elongation decreased. With decreasing of the final cooling temperature, the M/A island refined, tensile strength, Rt0.5/Rm, dσ/dεand uniform elongation increased. The optimum cooling process parameters are:the start cooling temperature is 690℃, the cooling rate is 15℃/s and the final cooling temperature is 400℃.
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