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对 Fe-C_6,Fe-X-C 及 Cu-Zn 合金相变驱动力的计算表明,贝氏体在热力学上不可能以切变机制形成。钢中贝氏体宽面上存在巨型长大台阶,长大界面呈弯曲形态,显示贝氏体很可能按台阶机制长大。在一些 Fe-Ni-C 合金及工业用钢中,奥氏体强度和 B_s 之间并无简单关系,B_s 却与碳和 Fe 的扩散系数呈线性关系,贝氏体相变在鼻部温度的孕育期与含 D~v_(Fe)的函数成正比,因此至少在 B_s 至鼻部温度,贝氏体相变的发生似受 Fe 原子扩散的控制。在一个低碳 Ni-Cr 钢中,贝氏体的界面形态和马氏体的不同,贝氏的惯习面近(1711)a,与马氏体惯习面(110)_(?)相距达13.3°,说明贝氏体相变不同于马氏体相变。在接近 Ms 时,相变驱动力足够大,贝氏体形态呈切变促发特征,贝氏体相变可能为切变型。对 Ag-Cd,Cu-Zn-Al 合金,18 Cr Ni WA 钢及其脱碳试样的内耗测定揭示:在孕育期内贝氏体预相变为局域软模导致的形核过程。
Calculations of the driving forces for the transformation of Fe-C_6, Fe-X-C and Cu-Zn alloys show that bainite can not be thermodynamically formed by a shear mechanism. Large bainitic steels exist in the steel, with large growth steps, and the growing interface is in a curved form, indicating that bainite is likely to grow by a step mechanism. In some Fe-Ni-C alloys and industrial steels, there is no simple relationship between the austenite strength and B_s, B_s but a linear relationship with the diffusivities of carbon and Fe, bainite transformation at nasal temperature The incubation period is proportional to the function of D ~ v_ (Fe), so the occurrence of bainite transformation seems to be controlled by the diffusion of Fe atoms, at least at B_s to nasal temperature. In a low-carbon Ni-Cr steel, the interface morphology of bainite is different from that of martensite, and the habitat of Bayesian is near (1711) a, which is away from the martensite habitus (110) Up to 13.3 °, indicating that the bainitic transformation is different from the martensitic transformation. When approaching Ms, the driving force for phase transformation is large enough, the bainite morphology appears to be shear-triggering, and the bainite transformation may be shear-thinning. The internal friction determination of Ag-Cd, Cu-Zn-Al alloy, 18 Cr Ni WA steel and its decarburized samples revealed that the pre-phase transformation of bainite into the nucleation process caused by local soft-mold during the incubation period.