Dynamic Recrystallization and Hot Workability of 316LN Stainless Steel

Abstract

Abstract:To identify the optimal deformation parameters for 316LN austenitic stainless steel, it is necessary to study the macroscopic deformation and the microstructural evolution behavior simultaneously in order to ascertain the relationship between the two. Isothermal uniaxial compression tests of 316LN were conducted over the temperature range of 950-1150˝C and for the strain rate range of 0.001-10 s´1 using a Gleeble-1500 thermal-mechanical simulator. The microstructural evolution during deformation processes was investigated by studying the constitutive law and dynamic recrystallization behaviors. Dynamic recrystallization volume fraction was introduced to reveal the power dissipation during the microstructural evolution. Processing maps were developed based on the effects of various temperatures, strain rates, and strains, which suggests that power dissipation efficiency increases gradually with increasing temperature and decreasing stain rate. Optimum regimes for the hot deformation of 316LN stainless steel were revealed on conventional hot processing maps and verified effectively through the examination of the microstructure. In addition, the regimes for defects of the product were also interpreted on the conventional hot processing maps. The developed power dissipation efficiency maps allow optimized processing routes to be selected, thus enabling industry producers to effectively control forming variables to enhance practical production process efficiency.

Nucleation and Grain Boundary Evolution in Dynamic Recrystallization of 316LN Steel During Hot Deformation

“…316LN austenitic stainless steel has been chosen to manufacture heavy key structural components in nuclear power plant owing to its excellent corrosion resistance, high temperature mechanical properties, and adequate weldability (Jones, 1996;Zhang et al, 2014). In recent years, the research of 316LN steel mainly focuses on two aspects: performance and hot deformation (Anita et al, 2006;Kim et al, 2009;Schwartz et al, 2010;Kim, 2012;Mathew et al, 2012;Samantaraya et al, 2012;Duan and Liu, 2013;Zhang et al, 2013;Chen et al, 2014;Samantaray et al, 2014;Sun et al, 2016). In terms of performance, researchers mainly studied creep and fatigue behavior (Schwartz et al, 2010;Mathew et al, 2012), stress corrosion crack (Anita et al, 2006), mechanical properties (Kim, 2012) and welding characteristics (Kim et al, 2009).…”

“…In terms of performance, researchers mainly studied creep and fatigue behavior (Schwartz et al, 2010;Mathew et al, 2012), stress corrosion crack (Anita et al, 2006), mechanical properties (Kim, 2012) and welding characteristics (Kim et al, 2009). In terms of hot deformation, Duan and Liu (2013) and Zhang et al (2013) conducted researches on cracking issue of 316LN steel during hot deformation, and presented prediction models for cracking, respectively; Chen et al (2014) predicted the microstructural evolution of 316LN steel using cellular automaton method; Hot processing map of 316LN steel was built by Sun et al (2016) who discussed the hot workability of 316LN steel; Samantaraya et al (2012), Samantaray et al (2014) revealed the unbalance phenomenon between energy input and energy dissipation during hot deformation of 316LN steel.…”

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

“…The constitutive equation is an important mathematical model to predict and analyze the relationship among temperature, strain rate, and flow stress in a wide hot deformation temperature range [36,37]. The dependence of flow stress to hot deformation variables can be analyzed by the well-known hyperbolic sine function [38] incorporated with the definition of the Zener-Hollomon parameter as follows:…”

Hot Deformation Behavior and Microstructural Evolution Characteristics of Ti-44Al-5V-1Cr Alloy Containing (γ + α2 + B2) Phases

“…Hot processing maps have been widely used to study deformation behaviors of many materials [5,16,17].Processing maps are normally constructed by overprinting power dissipation maps and instability regime maps. Processing maps are based on the dynamic materials model, the principles of which have been described earlier [18][19][20][21].…”

“…Hot processing maps have been widely used to study deformation behaviors of many materials [5,16,17]. Processing maps are normally constructed by overprinting power dissipation maps and instability regime maps.…”