封面

利用某钢管厂生产的不同批次三种成分体系X65管线钢管的检测数据，分析了钢管成分与性能的关系。结果表明，无论采用传统Mn-Mo-Nb系管线钢，还是Mn-Nb及Mn-Cr-Nb系管线钢，钢管的性能均能满足GB/T 9711—2017及API SPEC 5L等相关技术规范的要求。传统Mn-Mo-Nb系管线钢在低Mo、Nb条件下即可获得高的韧性；Mn-Nb及Mn-Cr-Nb系管线钢，管体及焊缝的强度随w（Nb）增加而增加；然而，管体、热影响区及焊缝的韧性则随w（Nb）增加到0.050%~0.060%时获得较大的改善效果；Cr对韧性有一定改善作用，但作用不显著。

Analysis of the Relationship between Chemical Composition and Mechanical Properties of X65 Pipeline Steel Pipe

Based on the test data of X65 pipeline steel pipes of different batches with three systems of chemical composition produced by a steel pipe factory, the composition and performance of the steel pipes were analyzed. Results show that the mechanical properties of the steel pipes, either by the traditional Mn-Mo-Nb series pipeline steel or Mn-Nb and Mn-Cr-Nb series pipeline steels, can meet the requirements of GB/T 9711—2017, API SPEC 5L and related technical specifications. The traditional Mn-Mo-Nb pipeline steel can obtain high toughness under low Mo and Nb conditions. For Mn-Nb and Mn-Cr-Nb pipeline steels, the strength of pipe bodies and weld increases with the increase of Nb content. However, the toughness of the tube bodies, the heat affected zones and the weld metals were significantly improved when the Nb content increased to 0.050%~0.060%. Cr may also improve toughness, but the effect is not significant.