中文摘要：

采用力学性能测试手段和电子显微分析技术对一种高铌（Nb）合金设计的X80管线钢的组织与性能进行了研究。结果表明：这种高Nb管线钢具有高的强韧性和低的韧脆转变温度，已成功应用于国内“西气东输二线”工程。对Nb元素在管线钢的细晶强化、组织强化和沉淀强化作用进行了分析。

英文摘要：

Mechanical property testing and microscope analysis were applied to evaluate the microstructure and mechanical properties of a high niobium-microalloyed X80 pipeline steel. The results show that the high niobium-microalloyed pipeline steel possesses higher strength-toughness and lower ductile-brittle transition temperature, and was already successfully applied to the Second West-east Gas Pipeline Project in China. The effects of niobium-microalloyed element on grain refinement, micro structure strengthening and precipitation hardening of pipeline steel were analyzed.