Control of Interphase Bowdlerizes in Steel

(α+γ)和(α+θ)片层组织经大量冷轧和退火热处理后形成了α晶粒度小于1μm的微双相组织。α相在(α+γ)中为亚晶结构，而α相在(α+θ)中既有高角晶界又有小角晶界。Y中的VC和α中的S-铜在固溶处理和时效后都与其母体共格。然而，在基质再结晶后，由于失去了原来的取向关系，它们变得不一致。在Ni-Cr合金面心立方晶界的析出过程中，无论是否存在近乎合理的取向关系，析出相(Bcc)/基体面(Fcc)界面都呈现出平面小平面，常含有台阶和规则排列的线缺陷。通过分析几何近重合位模型，平面小面的边界取向对应于相干原子密度较高的平面。研究了超高碳钢(α+θ)组织与超塑性行为的关系。对珠光体组织进行奥氏体化、淬火和回火处理，得到具有大角度α+θ晶界的(α)微双相组织。在973K拉伸试验中，奥氏体化、调质和回火的超塑性伸长率明显高于温轧试件。在奥氏体中非共格的MnS+V(C，N)复合析出物上的晶内铁素体自形体形核过程中，铁素体与其奥氏体基之间没有特定的取向关系，表明铁素体的转变织构是随机的。

The (α+γ) and (α+θ) lamellar structures are heavily cold rolled and annealed to form the microduplex structures of which α grain size is less than 1 μm. α phase exhibits a subgrain structure in the (α+γ) case whereas α phase contains both of high angle and low angle boundaries in the (α+θ) case.VC in y.and s-Cu in α are both coherent to their matrices after solution treatment and aging. However, they become incoherent by losing the original orientation relationship after the recrystallization of matrix. After losing coherency, these precipitates coarsens vary rapidly.In the bcc precipitation from fcc matrix in a Ni-Cr alloy, regardless of the presence of near rational orientation relationship, precipitate (bcc)/matrix(fcc) interphase boundaries exhibit planar facets that often contain ledges and regularly aligned line defects. The boundary orientations of the planar facets correspond to the planes with the higher densities of coherent atoms by analyzing the geometrical near coincidence site model.Relation between the (α+θ) microstructure and the superplastic behavior in ultra-high carbon steels has been studied. The austenitizing, quenching and tempering treatment of pearlite structure produces an (α+θ) microduplex structure with high angle α grain boundaries. The specimen austenitized, quenched and tempered shows much larger superplastic elongation in the tensile tests at 973K than the as warm rolled specimens. This structure also exhibits the superior strength-ductility balance at room temperature.In the nucleation of intragranular ferrite idiomorphs on the incoherent MnS+V(C, N) complex precipitates in austenite, there is no specific orientation relationship between the ferrite and its austenite matrix indicating that the ferrite transformation texture could be randomized.