一种制备耐低温管线钢的热处理方法,属于管线钢制造技术领域。通过对控轧控冷得到的粒状贝氏体组织进行两次不同温度的加热淬火,使组织均匀化的同时,显著细化组织,得到具有纳米级板条尺寸的贝氏体铁素体基体,保证了极好的强韧性配合再通过回火,消除应力的同时使铬的碳化物析出,进一步提高强度。所述制备耐低温管线钢的化学成分为含铬量在在0.5%~0.15%,其余为级管线钢的成分范围。优点在于,得到含有纳米尺度超细板条的贝氏体铁素体基体和均匀分布碳化物的混合组织,既确保了良好的低温韧性,又提高了强度,适用于高寒地区的管道铺设。

The invention relates to a heat treatment method for preparing low-temperature resistant pipeline steel, belonging to the technical field of pipeline steel manufacturing. By controlled rolling of granular bainite organization of controlled cooling for two different temperature quenching, make organization of homogenization, at the same time significantly refine the organization, with nanoscale lath bainite ferrite substrates size, guarantees the excellent tenacity cooperate again by tempering, eliminating stress at the same time, make the chromium carbide precipitation, further enhance the strength. The chemical composition of preparing low-temperature resistant pipeline steel is in the range of 0.5%~0.15% chromium content, and the rest is in the composition range of grade I pipeline steel. The advantages are that the mixed structure containing nano-scale ultra-fine lath bainitic ferrite matrix and uniformly distributed carbides not only ensures good low temperature toughness, but also improves the strength, which is suitable for pipeline laying in alpine regions.