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对硅锰铸钢在相变温度(A1)附近进行等温处理的研究表明,经磁场处理后的试样组织中存在更多的粒状珠光体组织。此粒状珠光体由两部分构成:一部分来自块状铁素体中直接析出粒状的不连续渗碳体;一部分来自等温过程中片状渗碳体的熔断。磁场通过促进铁素体的形核与长大,使较多的碳原子“陷落”在铁素体内以沉淀析出方式形成粒状渗碳体,处理温度越低,此作用越明显。此外,磁场下珠光体组成相磁致伸缩率存在差异,引起珠光体两组成相之间的应变能变化,有利于渗碳体以球状析出于奥氏体或铁素体中,也对粒状珠光体分数的增加作出贡献。
The isothermal treatment of Si-Mn cast steel around the phase transition temperature (A1) shows that more granular pearlite structure exists in the sample after magnetic field treatment. The granular pearlite is composed of two parts: one part comes from the granular precipitated cementite which is precipitated directly from the massive ferrite; and the other part comes from the melting of the lamellar cementite during the isothermal process. By promoting the nucleation and growth of ferrite, the magnetic field causes more carbon atoms to fall into the form of granular cementite precipitated in the ferrite. The lower the treatment temperature is, the more obvious this effect is. In addition, there are differences in the magnetostrictive ratio of the pearlite composition in the magnetic field, which leads to the change of the strain energy between two phases of the pearlite, which facilitates the precipitation of cementite in the form of spheres in austenite or ferrite, Body score to contribute to the increase.