《China Foundry》
Title:Hot deformation behavior of 2707 hyper duplex stainless steel
Author:*Ai-qin Wang1, 2, Pei Liu1, 2, Chen-lu Liu3, Hang Wang4, and Jing-pei Xie1, 2
Address: 1. College of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; 2. Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology, Luoyang 471023, China 3. Henan Aerospace Precision Machining Co., Ltd., Xinyang 464000, Henan, China 4. School of Mechatronics Engineering (Engineering Training Center), Xuchang University, Xuchang 461000, Henan, China
Key words:hyper duplex stainless steel; hot deformation; constitutive equation; softening mechanism
CLC Nmuber:TG142.71
Document Code:A
Article ID:1672-6421(2025)06-691-10
Abstract:
The hot deformation behavior of 2707 hyper duplex stainless steel (HDSS) was investigated through a hot compression test at 950 °C to 1,250 °C at strain rates of 0.01 s-1 to 10 s-1. Observations from the flow stress curves reveal a balance between work hardening and dynamic recovery at the beginning of the deformation and subsequently demonstrate various softening mechanisms with the increase of strain. At high strain rates, dynamic recovery is the prevailing mechanism, whereas, at medium and low strain rates, dynamic recrystallization becomes dominant. The constitutive equation was constructed, and the deformation activation energy was calculated to be 645.46 kJ·mol-1. The hot processing map was drawn based on the dynamic material model at a strain of 0.8. The results indicate that the hot workability of 2707 HDSS decreases due to its high alloying content. The microstructure evolution of 2707 HDSS at 1,050 °C was identified by means of electron backscatter diffraction and transmission electron microscopy. The results demonstrate that the ferrite completes dynamic recrystallization at the strain rate of 1 s-1. The softening process of austenite is influenced by ferrite and mainly experiences dynamic recovery. The austenite located at the α/γ phase boundaries tends to undergo dynamic recrystallization.