超高强度钢的精细组织与强韧性

THE MICROSTRUCTURE AND STRENGTHTOUGHNESS OF ULTRA-HIGH STRENGTH STEELS

对300M钢的不同淬火状态的组织进行了观察分析。结果表明,钢的组织主要由马氏体和贝氏体组成。一般来说,在一个奥氏体晶粒内存在四个马氏体领域。母相奥氏体和不同马氏体板条之间的取向可分别满足不同的等效的K-S关系。钢中的下贝氏体组织改变了显微组织特征和马氏体束中板条的相对取向,使有效晶粒或板条尺寸减小,从而使钢的强度和韧性获得改进。

An observation of microstructure features in the quenched ultra high strength steel(300M)at different temperatures was made. The results show that the structure consists of lath martensite and bainite. Usually, there is four martensitic fields in an austenite grain. The orientation between A and two martensitic laths may follow different equivalent K-S relationship. The lower bainite in steel changes microstructure features and relative orientation of lath martensite in a packet and thus decreaes effective grain size or lath size. The strength and toughness of steel are improved.