Microstructure transformation and strengthening-plasticization mechanism of S32205 duplex stainless steel after cold rolling and annealing

doi:10.13251/j.issn.0254-6051.2022.04.022

Abstract

Abstract: A novel process of cold rolling and annealing was designed to improve mechanical properties of S32205 duplex stainless steel. Both the tensile strength and the elongation were enhanced by this process. The microstructure characteristics and the strengthening mechanism of the new-designed microstructure were investigated by means of room temperature tensile tests, optical microscope, electron back-scattered diffraction analysis and thermodynamic calculations, etc. The results show that the microstructure of the S32205 duplex stainless steel obtained by the process exhibits a bimodal grain size distribution with fine austenite precipitated in the ferrite phase. Under the combined effect of fine-grained strengthening and back stress strengthening caused by the incompatible deformation between the two phases, the strength and plasticity of the tested steel are both improved compared with the conventional solution heat treatment process.

Key words: duplex stainless steel, microstructure modulation, fine-grained strengthening, back stress strengthening, mechanical properties

CLC Number:

TG156

Lü Jiesheng, Song Zhigang, He Jianguo, Feng Han, Zheng Wenjie, Zhu Yuliang. Microstructure transformation and strengthening-plasticization mechanism of S32205 duplex stainless steel after cold rolling and annealing[J]. Heat Treatment of Metals, 2022, 47(4): 141-145.

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