Abstract

Orientation microscopy (EBSD) has been used to investigate the structure of austenitic stainless steel containing 18% Cr and 9 wt % Ni after its long-term operation at high temperatures and neutron irradiation. The γ → α shear transformation has been implemented partially in the samples during deformation-free cutting. Austenite has decomposed due to isotropic stresses oriented normally to the surface under study. The precision of orientation relationships (ORs), such as Kurdjumov–Sachs, Nishiyama–Wassermann, Greninger–Troiano, and others during γ → α transformation has been comparatively analyzed. The Greninger–Troiano OR has been found to be the best possible OR describing the transformation in this case. The α phase has been shown to nucleate at coherent twin boundaries (Σ3 in the coincidence site lattice model) between austenite grains. This has determined the variants of the current ORs and the unambiguous crystallographic orientation of α-phase grains.

中文翻译：

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特殊边界对奥氏体不锈钢γ→α相变的影响

摘要

取向显微镜 (EBSD) 已被用于研究在高温和中子辐射下长期运行后含有 18% Cr 和 9 wt% Ni 的奥氏体不锈钢的结构。在无变形切削过程中，已在样品中部分实现了 γ → α 剪切转变。奥氏体由于各向同性应力而分解，这些应力通常指向所研究的表面。对Kurdjumov-Sachs、Nishiyama-Wassermann、Greninger-Troiano等γ→α变换过程中取向关系（ORs）的精度进行了比较分析。在这种情况下，Greninger-Troiano OR 被发现是描述转换的最佳 OR。已显示α相在奥氏体晶粒之间的相干孪晶边界（重合位点晶格模型中的Σ3）处成核。