Deformation Characteristic and Constitutive Modeling of 2707 Hyper Duplex Stainless Steel under Hot Compression

Abstract

Hot deformation behavior and microstructure evolution of 2707 hyper duplex stainless steel (HDSS) were investigated through hot compression tests in the temperature range of 900-1250 • C and strain rate range of 0.01-10 s −1 . The results showed that the flow behavior strongly depended on strain rate and temperature, and flow stress increased with increasing strain rate and decreasing temperature. At lower temperatures, many precipitates appeared in ferrite and distributed along the deformation direction, which could restrain processing of discontinuous dynamic recrystallization (DRX) because of pinning grain boundaries. When the temperature increased to 1150 • C, the leading softening behaviors were dynamic recovery (DRV) in ferrite and discontinuous DRX in austenite. When the temperature reached 1250 • C, softening behavior was mainly DRV in ferrite. The increase of strain rate was conducive to the occurrence of discontinuous DRX in austenite. A constitutive equation at peak strain was established and the results indicated that 2707 HDSS had a higher Q value (569.279 kJ·mol −1 ) than other traditional duplex stainless steels due to higher content of Cr, Mo, Ni, and N. Constitutive modeling considering strain was developed to model the hot deformation behavior of 2707 HDSS more accurately, and the correlation coefficient and average absolute relative error were 0.992 and 5.22%, respectively.

Effects of Heat Input on Microstructure, Corrosion and Mechanical Characteristics of Welded Austenitic and Duplex Stainless Steels: A Review

“…DSS is not as resistant as ferritic SS but more resistant than austenitic against SCC [15]. The susceptibility of DSS to SCC depends on many factors, including alloying elements [120,121], microstructures [122,123], applied stresses [124,125], and environment [126][127][128][129].…”

Plastic Deformation Behavior in Steels during Metal Forming Processes: A Review

“…In addition, processing temperatures and strain rates are equally important for the plastic deformation behavior. Therefore, the dynamics of TMP can be understood through the investigation of microstructural changes combined with interpretations of trends of flow stress-strain curves which depend on DRV and DRX, and SRX [76,77]. I.…”

Constitutive Equation and Hot Processing Map of a Nitrogen-Bearing Martensitic Stainless Steel

“…A, α and n are the material constants, and α = β/n 1 , Z is the Zener−Hollomon parameter. According to previous research [30,31], the power law expression of true stress in Equation 1is generally used for the low stress level, conversely the exponential law in Equation 2is preferred for the high stress level, while the hyperbolic sine law in Equation 3is suitable for all the stress levels. In the present study, the hyperbolic sine law in Equation 3is applied for the description of the hot deformation behavior of the experimental material.…”