Cu-B系超低碳钢中贝氏体组织形态探讨

STUDY OF BAINITIC MICROSTRUCTURE IN ULTRA-LOW CARBON STEEL CONTAINING COPPER AND BORON

讨论了低(超低)碳贝氏体钢中显微结构的特征及其与钢材力学性能的关系。研究发现影响力学性能的因素为:两种贝氏体形态αB(位错亚结构组织)及α°B(板条结构)各占的比例多少;位错密度,亚结构特征;板条结构的宽度、长度;M-A岛及沉淀析出相的数量、尺寸大小和分布均影响钢的强韧性;控制轧制过程中的形变量、终轧温度和冷却速度直接影响上述各种微结构的形态、数量,从而影响钢的强韧性。

The study deals with the feature of microstructure and its relationship with the properties of low (ultra-low) carbon bainitic steel. It is discovered that the influencing factors as follows: the fraction of two bainite structures αB (dislocation-substructure) and α°B (sheef-like structure), dislocation density, substructure feature, the width and length of lath structure, the number, size and distribution of M-A island and precipitations. All of them have influence on strength and toughness of the steel, therefore amount of deformation, finishing temperature and cooling rate in controlled-rolling process have direct effect on the form and amount of above mentioned various microstructures and then on the strength and toughness of steel.