Acta Metallurgica Sinica (English Letters) ›› 2024, Vol. 37 ›› Issue (4): 695-702.DOI: 10.1007/s40195-023-01626-4

Previous Articles     Next Articles

Combination of High Yield Strength and Improved Ductility of 21Cr Lean Duplex Stainless Steel by Tailoring Cold Deformation and Low-Temperature Short-Term Aging

Zhenghong Liu1,2, Zhigang Wu1,2, Ying Han1,2,3(), Xiaolei Song1,2,3, Guoqing Zu1,2,3, Weiwei Zhu1,2,3, Xu Ran1,2,3()   

  1. 1Key Laboratory of Advanced Structural Materials, Ministry of Education, Changchun University of Technology, Changchun, 130012, China
    2School of Materials Science and Engineering, Changchun University of Technology, Changchun, 130012, China
    3Jilin Province Key Laboratory of Advanced Materials Processing and Application for Rail Transit, Changchun University of Technology, Changchun, 130012, China
  • Received:2023-08-28 Revised:2023-09-13 Accepted:2023-09-25 Online:2024-04-10 Published:2023-11-24
  • Contact: Ying Han, hanying_118@sina.com; Xu Ran, ranxu@ccut.edu.cn

Abstract:

Proper matching of cold-rolled deformation and low-temperature short-term aging can simultaneously enhance the strength and ductility of the lean duplex stainless steel. To investigate this, the microstructure evolution of cold-rolled and aging steels was observed by using scanning electron microscopy, transmission electron microscopy and electron backscattered diffraction. Additionally, the phase volume fraction was measured using X-ray diffraction. In this study, it was observed that the elongation of 21Cr lean duplex stainless steel significantly increased to 16.7% after undergoing moderate cold deformation (~ 40% reduction) and subsequent aging treatment at 550 °C for 30 min. Remarkably, the material still maintained a high yield strength of 1045 MPa. Such an excellent mechanical property was attributed to a unique microstructure combination of fine α'-martensite, twins, coarsened austenite resulting from partial martensite reverse transformation, and two-phase fine layered structure. The result of this study may open up new horizons for the alloy development in order to overcome the low ductility of cold-rolled high-strength lean duplex stainless steel.

Key words: Lean duplex stainless steel, Cold rolling, Aging, Microstructure, Mechanical properties, Use our pre-submission checklist