材料期刊网

根据实验证据提出:在钢的马氏体转变过程中,fcc→bcc(或bct)晶格改组时所需的原子相对位置变化是通过畸变fcc奥氏体晶格内的偏位错运动实现的,其方式有两种:一种是偏位错沿(1/m)〈112〉_f/{111}_f中的一个滑移系运动导致的主剪切原子位移;另一种是不同共轭{111}_f滑移面内偏位错同时或先后开动联合造成的M=(1/n)[〈112〉_(f1)/{111}_1+〈112〉_(f2)/{111}_2]复合原子位移。由此出发提出了钢淬火时奥氏体向马氏体转变的偏位错滑移共轭复合原子位移机制,并按此机制对马氏体与奥氏体之间的位向关系,马氏体惯析面及淬火马氏体中的一些特有现象给出了晶体几何学的解释。

With the aid of TEM observation on the martensite transformation of three steels, the relative position changes between atoms caused by the dislocation slip during fcc→bcc (or bet)lattice variation are mainly carried through shears in combination with different slip systems along<112>_f/{111}_f in the distorted fee lattice. Two types of these changes are: (1) the atom displacement of main shear only along one slip system of (1/m)<112>_f/{111}_f and (2)M=(1/n)[<112>_(f1)/{111}_(f1)+<112>_(f2)/{111}_(f2)] complex displacement obtained by all dislocations operated in different {111}_f conjugate sIip plane (n>6). Thus, an atom displacement mechanism of which the austenite transforms into martensite through conjugate complex slips of partial dislocation during quenching has been proposed. Based upon this mechanism, the crystalline geometry explanation may be undoubtedly made on the orientation correlation between matensite and austenite matrix, as well as the martensite habit planes and some special phenomena in quenched martensite.