基于应变设计的X80HD管线钢生产技术研究

为了研究X80HD管线钢的抗大变形能力，分析了轧制工艺对基于应变设计的X80HD管线钢组织性能的影响，并研究了制管工艺过程对管线钢的力学性能的影响规律。结果表明，铁素体/贝氏体双相组织的管线钢，随着始冷温度降低，先共析铁素体和析出物数量增加；随着终冷温度的降低，贝氏体的数量增加，相变强化作用增强，管线钢的抗拉强度提高更为明显；在制管过程中，钢管的屈服强度增加明显，且随着扩径率的增大，钢管屈服强度呈比例增大，但抗拉强度变化不大；当始冷温度约700 ℃和终冷温度低于450 ℃时，钢中的先共析铁素体和贝氏体双相组织组成控制合适，该管线钢具有优良的变形能力，能较好地满足大应变管线钢的性能要求。

Strain-based Design for X80HD Pipeline Steel Production Technology Research

In order to study the high deformation resistance of X80HD pipeline steel, in this article, it analyzed the influence rule of rolling process on microstructure and mechanical properties of X80HD pipeline steel with strain-based design, and researched the influence of pipe making process on pipeline steel mechanical properties. The results showed that ferrite/bainite dual phase organization pipeline steel, along with start cooling temperature reducing, the quantity of proeutectoid ferrite and precipitates increased; as the final cooling temperature decreased, the quantity of bainite increased, the effect of phase transformation strengthening increased, so the tensile strength increase of pipeline steel was more obvious. In the pipe making process, the yield strength of pipe steel obviously increased, along with the expansion ratio increasing, the yield strength increased according to certain proportion, but the tensile strength changed little. When the start cooling temperature at about 700 ℃ and the final cooling temperature below 450 ℃, the proportion of ferrite and bainite dual-phase structure in steel was appropriate. This pipeline steel was with excellent deformability, which can better meet the performance requirements for large strain pipeline steel.