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对硅锰铸钢在A1点以上温度进行磁场等温处理诱发珠光体(P)相变的可能性进行了研究,探讨了P形核位置、领先相、核心形态及长大方式。结果表明,①磁场可在A1点以上的温度诱发P,随着磁场作用时间的延长,所诱发的P量的增加主要是P团长大所致,存在一定数量具铁磁性的先共析相、磁场作用时间及其强度的大小是决定在A1以上温度诱发P量的关键因素;②初期形成的P形态并不都呈现出两组成相的平行排列,而是受在晶粒交叉部位、晶界处优先形核的先共析相铁素体(F)形态的限制;③在P形核与长大过程中,P片间距并不是常数,F与渗碳体(Cm)的宽度均下降,降速以Cm为快;④P中Cm可在F片内沉淀析出。Cm的形核与长大速度是制约P形成的主要因素。
The possibility of phase transition of pearlite (P) induced by the magnetic field isothermal treatment of silicon-manganese cast steel at the temperature above A1 was studied, and the P-nucleus position, leading phase, core morphology and growth pattern were discussed. The results show that ① the magnetic field can induce P at a temperature above A1, and the increase of the amount of P induced by the prolongation of the magnetic field is mainly due to the growth of the P group. There are a certain number of ferromagnetic proeutectoid phases , The time of magnetic field and the magnitude of its intensity are the key factors that determine the amount of P induced by temperature above A1; (2) the initial formation of P morphology does not all show the parallel arrangement of two phases, (P) ferrite (F) shape preferentially nucleated in the boundary; ③In the P-nucleation and growth process, the P-spacing is not constant and the width of F and cementite (Cm) , Slow down to Cm as fast; ④ P Cm in F chip precipitation. Cm nucleation and growth rate is the main factor restricting the formation of P.