中文摘要：

为了适应管道的大位移环境和高强度管线钢发展的需要，研制和开发了大变形管线钢。研究结果表明，大变形管线钢的主要性能特征是在保证高强韧性的同时，要求具有低的屈强比、较高的均匀伸长率和形变强化指数；大变形管线钢的组织特征为B＋F和B＋M/A双相组织。通过适度加速冷却方法、双相区加速冷却方法和延迟加速冷却方法，可以获取B＋F大变形管线钢；通过在线配分技术，可以获取B＋M/A大变形管线钢。

英文摘要：

In order to adapt to the large displacement environment of pipeline and to meet the demand of developing high strength pipeline steel , a kind of high deformability pipeline steel has been researched and developed in recent years. The study result indicated that the main performance characteristic of large deformability pipeline steel is to ensure high toughness and with lower yield ratio,higher uniform elongation and higher strain hardening exponent. The microstructure characteristic of large deformability pipeline steel is dual-phase microstructure of B＋F and B＋M/A. The B＋F pipeline steel can be obtained by the mild accelerated cooling, dual-phase region accelerated cooling and delayed accelerated cooling. The B＋M/A pipeline steel can be obtained by the heating on-line partitioning method.