Microstructural and Hardness Evolution in a Duplex Stainless Steel Processed by High-Pressure Torsion

Crystals

Yi Huang¹  TerenceG. Langdon²  Ming Ma³  ChengWei Tian³  Hua Ding⁴ 

[1] Department of Design and Engineering, Faculty of Science and Technology, Bournemouth University, Poole, Dorset BH12 5BB, UK;Materials Research Group, Department of Mechanical Engineering, University of Southampton, Southampton SO17 1BJ, UK;School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China;State Lab of Rolling and Automation, Northeastern University, Shenyang 110819, China;

关键词: duplex stainless steel;    Hall–Petch relationship;    high-pressure torsion;    severe plastic deformation;    ultrafine grains;   

DOI  :  10.3390/cryst10121138

来源: DOAJ

【 摘 要 】

The duplex stainless steel 2205, designated DSS2205 and having a duplex structure comprising ferrite and austenite phases, was processed by high-pressure torsion (HPT) and the microstructural and hardness evolutions were investigated after various HPT revolutions and at different positions within the specimens. The results show that the grain refinement induced by severe deformation processing is different in the ferrite and austenite phases such that the ferrite grains are refined via dislocation subdivision, whereas grain refinement in the austenite phase depends mainly on the interaction of dislocations and twin boundaries at relatively low strains. When the numbers of revolutions increases, the grain refinement in austenite restricts the occurrence of deformation twinning so that dislocation slip becomes dominant. During HPT processing, the effect of the phase boundaries on the mechanical properties of the alloy is very significant. The results show the average width between two adjacent phases and the hardness of the alloy are generally consistent with the classical Hall–Petch relationship.

【 授权许可】

Unknown