Intercritically deformed steels present combinations of different types of ferrite, such as deformed ferrite (DF) and non-deformed ferrite (NDF) grains, which are transformed during the final deformation passes and final cooling step. Recently, a grain identification and correlation technique based on EBSD has been employed together with a discretization methodology, enabling a distinction to be drawn between different ferrite populations (NDF and DF grains). This paper presents a combination of interrupted tensile tests with crystallographic characterization performed by means of Electron Backscatter Diffraction (EBSD), by analyzing the evolution of an intercritically deformed micro-alloyed steel. In addition to this, and using the nanoindentation technique, both ferrite families were characterized micromechanically and the nanohardness was quantified for each population. NDF grains are softer than DF ones, which is related to the presence of a lower fraction of low-angle grain boundaries. The interrupted tensile tests show the different behavior of low- and high-angle grain boundary evolution as well as the strain partitioning in each ferrite family. NDF population accommodates most of the deformation at initial strain intervals, since strain reaches 10%. For higher strains, NDF and DF grains behave similarly to the strain applied.

中文翻译：

---

通过间断拉伸试验分析临界变形微结构中的应变分配

临界变形钢呈现出不同类型铁素体的组合，例如变形铁素体（DF）和非变形铁素体（NDF）晶粒，它们在最终变形道次和最终冷却步骤中发生转变。近来，基于EBSD的晶粒识别和相关技术已与离散化方法一起使用，从而可以在不同的铁素体种群（NDF和DF晶粒）之间进行区分。本文通过分析临界变形微合金钢的演化，提出了通过电子背散射衍射（EBSD）进行的断续拉伸试验与晶体学表征的组合。除此之外，并使用纳米压痕技术，对两个铁素体族进行了微机械表征，并对每个群体的纳米硬度进行了量化。NDF晶粒比DF晶粒更软，这与低角度晶粒边界的存在有关。中断的拉伸试验显示了低角度和高角度晶界演化的不同行为以及每个铁素体族中的应变分配。由于应变达到10％，NDF群体在初始应变间隔处承受了大部分变形。对于更高的应变，NDF和DF晶粒的行为与所施加的应变相似。中断的拉伸试验显示了低角度和高角度晶界演化的不同行为以及每个铁素体族中的应变分配。由于应变达到10％，NDF群体在初始应变间隔处承受了大部分变形。对于更高的应变，NDF和DF晶粒的行为与所施加的应变相似。中断的拉伸试验显示了低角度和高角度晶界演化的不同行为以及每个铁素体族中的应变分配。由于应变达到10％，NDF群体在初始应变间隔处承受了大部分变形。对于更高的应变，NDF和DF晶粒的行为与所施加的应变相似。