Microstructure and Mechanical Properties of Gradient Nanostructured Q345 Steel Prepared by Ultrasonic Severe Surface Rolling

Chao Ge; Weilong Meng; Handui Feng; Muchun Cui; Lei Dong; Tianfeng Miao; Yantong Huo; Jiemin Wu; Jing Han

doi:10.1155/2023/7705844

Microstructure and Mechanical Properties of Gradient Nanostructured Q345 Steel Prepared by Ultrasonic Severe Surface Rolling

Scanning. 2023 Apr 17:2023:7705844. doi: 10.1155/2023/7705844. eCollection 2023.

Authors

Chao Ge¹, Weilong Meng^{2

3}, Handui Feng¹, Muchun Cui¹, Lei Dong¹, Tianfeng Miao¹, Yantong Huo¹, Jiemin Wu¹, Jing Han^{2

3}

Affiliations

¹ Xuzhou XCMG Mining Machinery Co. LTD, Xuzhou 221000, China.
² CUMT-XCMG Mining Intelligent Equipment Technology Research Institute, China University of Mining and Technology, Xuzhou 221116, China.
³ School of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, China.

Abstract

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 μm. 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.