本发明提供了一种耐二氧化碳腐蚀无缝钢管及其制备方法，涉及管线钢制造技术领域，所制备的钢管具有优异的抗二氧化碳腐蚀性能，其腐蚀速率低于0.06mm/a，且造价低；该钢管的成分包括C 0.03～0.08％，Cr 5.50～8.5％，Ni 0.1～2％，Nb 0.010～0.055％，P≤0.012％，S≤0.006％，N≤0.010％，余量为Fe及不可避免的杂质；该方法包括：S1、按各成分质量比冶炼、浇注成钢锭；S2、锻造和第一次退火；S3、第二次退火；S4、管材轧制，得到荒管；S5、热处理。本发明提供的技术方案适用于无缝钢管制备的过程中。

The invention provides a carbon dioxide corrosion-resistant seamless steel pipe and a preparation method thereof, and relates to the technical field of pipeline steel manufacturing. The prepared steel pipe has excellent carbon dioxide corrosion resistance, the corrosion rate is lower than 0.06mm/a, and the cost is low; The composition of the steel pipe includes C 0.03～0.08%, Cr 5.50～8.5%, Ni 0.1～2%, Nb 0.010～0.055%, P≤0.012%, S≤0.006%, N≤0.010%, the balance is Fe and non- Avoided impurities; the method includes: S1, smelting and pouring into steel ingots according to the mass ratio of each component; S2, forging and first annealing; S3, second annealing; S4, tube rolling to obtain a waste tube; S5, heat treatment . The technical scheme provided by the present invention is applicable to the process of preparing seamless steel pipes.