We propose a novel processing technique called Stair Rolling Treatment (SRT) to generate a graded sheet with a functionally graded microstructure along its longitude. The SRT process generates a longitudinal plastic strain gradient by the cold rolling of a longitudinally variable-thickness plate. Microstructural and mechanical characterisation of the 304L stainless steel SRT sheets, are performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron channelling contrast imaging (ECCI), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) techniques, microhardness measurements, and uniaxial tensile tests. Mechanical characterisations show that the gradients of phase and grain size lead to mechanical incompatibility and hence non-uniform stress and strain during tensile tests. The annealed SRT sheet samples demonstrate a good combination of strength and ductility.

中文翻译：

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梯级轧制分级奥氏体不锈钢板的特性

我们提出了一种称为楼梯轧制处理 (SRT) 的新型加工技术，以生成沿其经度具有功能分级微观结构的分级板材。SRT 工艺通过冷轧纵向可变厚度板产生纵向塑性应变梯度。通过 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、电子通道对比成像 (ECCI)、电子背散射衍射 (EBSD)、透射电子显微镜 (TEM) 对 304L 不锈钢 SRT 片材进行微观结构和机械表征) 技术、显微硬度测量和单轴拉伸试验。机械特性表明，相和晶粒尺寸的梯度会导致机械不相容性，从而导致拉伸试验中的应力和应变不均匀。