Abstract: The general chemical compositions of microalloyed intragranular ferrite steels are 0.2~0.4C,0.2～0.8Si, 1.0~1.7Mn,0.05～0. 15V. It is a main measure to increase the strength and toughness of ferite-pearlite microalloyed steel using recrystallized forging and rolling to control cooling rate in phase transformation range in order to promote formation of fine dispersed intragranular ferrite structure. Recently an important advance to increase strength and toughness of this steel is to select suitable deoxidizing process, get fine, dispersed oxides with definite ingredient which become precipitated nucle- us of MnS, VN and V4C₃ .The chemical compositions and production of microalloyed intragranular ferrite steels at home and abroad are presented and the formation mechanism of intragranular ferrite is analyred in this paper.

Key words: Intragranular Ferrite, Microalloyed Steel, High Strength and Toughness, Development

摘要： 晶内铁素体型微合金非调质钢成分一般为(%):0.2～0.4C,0.2～0.8Si,1.0～1.7Mn,0.05~ 0.15V,采用再结晶锻造或轧制、控制相变区间冷却速率以促进形成细小弥散的晶内铁素体组织是提高铁素体 -珠光体型微合金非调质钢强韧性的重要手段。选择合适的脱氧工艺，获得一定组成的细小、弥散的氧化物， 使之成为MnS、VN和V4C₃ 等的析出核心，利于晶内铁素体析出的氧化物冶金是近来提高该钢强韧性的重要 进展。介绍了国内外晶内铁素体型微合金非调质钢的化学成分和生产工艺，并分析了晶内铁素体形成机理。

关键词: 晶内铁素体, 微合金非调质钢, 高强韧性, 进展