Dependency of Portevin-LeChatelier Effect and Microstructure Characteristics of 9Cr ODS Steels on Strain Rates Upon Hot Deformation
Dependency of Portevin-LeChatelier Effect and Microstructure Characteristics of 9Cr ODS Steels on Strain Rates Upon Hot Deformation
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DOI：
10.1007/s12540-023-01482-y
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发表时间：
2023-06
影响因子：
3.5
通讯作者：
Xiaosheng Zhou;Yaran Zhang;Yan-mo Li;M. Yuan;Guodong Li;Zhen-Yu Chen;Huang Zhang
中科院分区：
文献类型：
--
作者：
Xiaosheng Zhou;Yaran Zhang;Yan-mo Li;M. Yuan;Guodong Li;Zhen-Yu Chen;Huang Zhang
The flow stress and microstructure evolution of 9Cr oxide dispersion strengthened (ODS) steels were investigated by isothermal compression at 1000–1150oC with strain rates from 0.001 to 1 s− 1. Microstructure characteristics of ODS steels under various condition were studied using the EBSD and TEM techniques. At each deformation temperature, PortevinLe--Chatelier (PLC) effect characteristics of repeated serrated stress was observed, as the strain rates were 0.01, 0.1 and 1 s− 1. The serrations fluctuated about the mean flow curve in quick succession, and the critical strain for the PLC effect was related to both the deformation temperature and strain rates. The stress drops at strain rates of 0.01 and 0.1 s− 1were smaller than those at 1 s− 1. The strain rate affected the dynamic recovery and recrystallization of austenite grains, as well as the texture components of martensite transformed from austenite. Cap-shaped oxide particles in as-fabricated and hot deformed steels were characterized in detail. The cap parts of cap-shaped oxide particles were depleted of alloying elements, and the caps were crystal or amorphous. Large-sized oxide particles were easier to be deformed than small-sized ones. Despite of the oxide deformation, the PLC effect was still suggested to be related to the solute-dislocation interaction.Graphical Abstract
