Dynamic Recrystallization and Recovery Behaviors in Austenite of a Novel Fe-1.93Mn-0.07Ni-1.96Cr-0.35Mo Ultrahigh Strength Steel

Yongli Chen,Xuejiao Zhou,Yueyue Jiang,Fei Tan,Yuhua Li,Tingyue Gu

doi:10.1155/2021/2809145

Yongli Chen, Xuejiao Zhou + Show 4 more

Open Access

https://doi.org/10.1155/2021/2809145

Copy DOI

Abstract

Due to the complex composition and high proportion of alloys in traditional ultrahigh strength steel, the dilemma caused by ultrahigh strength and low toughness in casting and forging processes requiring subsequent heat treatment can be mitigated with an efficient and economical rolling process. In this work, the effect of deformation parameters on dynamic recrystallization (DRX) and dynamic recovery (DRV) is discussed through stress-strain analysis, the DRV mathematical model is obtained, and then the dynamic recrystallization activation energy, Zener–Hollomon equation, and hot working equation are obtained. The critical strain of DRX detected by the P-J method is ε c / ε p = 0.631 , which indicates that dynamic recrystallization of this novel steel is relatively easy to achieve by the rolling process. These models and conclusions have potential to be generalized for the formulation of process specification and process configuration without requiring extensive material testing.

Highlights

Ultrahigh strength steel (UHSS) can reduce steel consumption and improve the safety coefficient so significantly that it is widely used in various industrial fields
DRX curve can be obtained by three different mechanisms: discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), and geometric dynamic recrystallization (GDRX) [6, 7]. e stacking fault energy of UHSS attributed to Fe-1.93Mn-0.07Ni-1.96Cr-0.35Mo steel is relatively complex, which can be estimated qualitatively from the deformation of work hardening in the flow stress curves [8]
Little attention has been paid to the high stacking fault energy of the UHSS flow behaviors, which aimed at the efficient direct hot rolling production process

Summary

Introduction

Ultrahigh strength steel (UHSS) can reduce steel consumption and improve the safety coefficient so significantly that it is widely used in various industrial fields. New economic and efficient technology is urgently needed to develop to produce UHSS Physical metallurgical behaviors such as work hardening, dynamic restoration, and dynamic recrystallization compete in development during the austenite hot deformation of UHSS, which determines the rheological stress. E stacking fault energy of UHSS attributed to Fe-1.93Mn-0.07Ni-1.96Cr-0.35Mo steel is relatively complex, which can be estimated qualitatively from the deformation of work hardening in the flow stress curves [8]. Little attention has been paid to the high stacking fault energy of the UHSS flow behaviors, which aimed at the efficient direct hot rolling production process. A thermodynamic simulation experiment for the hot rolling process of experimental steel was carried out to analyze and establish the constitutive equation and dynamic recrystallization model of austenite subjected to the hot deformation. We offer an alternative scheme to develop a more economic and efficient process for the UHSS production

Experimental Materials and Procedures

Results and Discussion

Flow Characteristics and Deformation Mechanisms