中文摘要：

综述了新一代高性能（屈服强度500～700MPa级）贝氏体钢系列组织控制与形成超细组织的物理冶金原理及工艺技术的发展情况，系统论述了Mn-Mo-Nb-B低碳微合金钢的组织特性、形成温度区间，阐明了中温转变组织超细化的基本理论思路及弛豫一析出一控制相变技术的基本原理，介绍了组织控制与超细化技术在提高低碳微合金钢性能上的应用。

英文摘要：

The metallurgical principle and processing technology to develop ultra-fine low carbon bainitic steel have been overviewed. For the Mn-Mo-Nb-B low carbon mieroalloyed steel, the intermediate transformation mierostmcture characteristics and its transformation temperature range have been revealed. The relaxation-precipitation-phase transformation con- trol （RPC） principle to refine the bainite has been introduced. By the application of microstmcture control and ultra-fine technology, high performance low carbon bainitic steel has been developed.