Xuzhou XCMG Mining Machinery Co. LTD, Xuzhou 221000, China.
CUMT-XCMG Mining Intelligent Equipment Technology Research Institute, China University of Mining and Technology, Xuzhou 221116, China.
Scanning. 2023 Apr 17;2023:7705844. doi: 10.1155/2023/7705844. eCollection 2023.
In this work, ultrasonic severe surface rolling (USSR), a new surface nanocrystallization technique, is used to prepare gradient nanostructure (GNS) on the commercial Q345 structural steel. The microstructure of the GNS surface layer is characterized by employing EBSD and TEM, and the result indicates that a nanoscale substructure is formed at the topmost surface layer. The substructures are composed of subgrains and dislocation cells and have an average size of 309.4 nm. The GNS surface layer after USSR processing for one pass has a thickness of approximately 300 m. The uniaxial tensile measurement indicates that the yield strength of the USSR sample improves by 25.1% compared to the as-received sample with slightly decreased ductility. The nanoscale substructure, refined grains, high density of dislocations, and hetero-deformation-induced strengthening are identified as responsible for the enhanced strength. This study provides a feasible approach to improving the mechanical properties of structural steel for wide applications.
在这项工作中，采用超声强烈表面轧辊处理（USSR）这一新型表面纳米晶化技术，在商用 Q345 结构钢上制备梯度纳米结构（GNS）。采用 EBSD 和 TEM 对 GNS 表面层的微观结构进行了表征，结果表明在最顶层形成了纳米尺度的亚结构。这些亚结构由亚晶粒和位错胞组成，平均尺寸为 309.4nm。经 USSR 处理一次后的 GNS 表面层厚度约为 300μm。单向拉伸测量表明，与原始样品相比， USSR 样品的屈服强度提高了 25.1%，而延性略有下降。纳米尺度的亚结构、细化晶粒、高密度位错以及异变形诱导强化被认为是导致强度提高的原因。本研究为提高结构钢的力学性能提供了一种可行的方法，具有广泛的应用前景。
