Strain-induced Precipitation Research Articles

Influence of deformation temperature on flow stress and dynamic metallurgical phenomena in Al–5.81Zn–1.65Mg alloy subjected to thermomechanical processing

To advance the T5 treatment process for Al–5.81Zn–1.65Mg alloys, this study explored the influence of deformation temperature on the solution temperature, ultrafine grain (UFG) formation via dynamic recrystallization (DRX), and strain-induced dynamic precipitation (SIDP) during thermomechanical processing at 300–500 ℃, with a 70% reduction and a strain rate of 1s−1. The flow curve exhibited pronounced work hardening (WH) at 300–350 ℃, whereas a dynamic recovery-type flow curve was observed at 450–500 ℃. As the temperature increased from 300 to 500 °C, the 1st WH rates (ε=0.2–0.4) were 55, 37.5, 20, 8.5, and 10MPa, respectively. Larger DRX grains were formed at higher temperatures. The DRX rate ranged 20%–30% at 300–400 ℃ and increased to 60% at 500 ℃. The texture gradually transitioned from Goss {011}<100> to brass {110}<112> with an increase in the deformation temperature from 300 to 500 ℃. Discontinuous DRX occurred mainly near the grain boundaries and precipitates at 300–400 ℃, shifting to continuous DRX at temperatures ranging from 400 to 500 ℃. At 300 and 400 ℃, larger precipitates (10–50nm) and smaller ones (<10nm) were observed within grains and along boundaries. Precipitates at 300 ℃ were larger and denser than those at 400 ℃, with η’, and T’ phases formed through SIDP. For this alloy, considering the formation of UFG and ensuring sufficient solubility, the appropriate deformation temperature range was 400–500 ℃.

Effects of Nb Solute and Precipitates on the Continuous Cooling and Isothermal Transformation of Pearlite in High‐Carbon Steel Wire Rods

To investigate the influence mechanism of Nb solute and precipitates on pearlite transformation, the effects of Nb content and heat‐treatment process on pearlite transformation and microstructure in high‐carbon steel wire rods are analyzed in this article. During the austenite deformation stage, the increase in solute Nb and strain‐induced precipitates (SIPs) suppresses austenite recrystallization, while the decrease in prior austenite grain size promotes the reduction of refined pearlite colonies size. During the continuous cooling transformation process, an increase in Nb content and cooling rate increases the supercooling of pearlite transformation and refines the interlamellar spacing (ILS) of pearlite. During the isothermal transformation process, the increase in isothermal temperature increases the incubation period of pearlite transformation and slows down the rate of pearlite transformation. With the increase in Nb content, the incubation period of pearlite transformation lengthens. But uneven distribution of C in austenite is caused by the SIP, which promotes interface migration, and shorts the pearlite transformation time. In high‐carbon steel wire rods, the refinement of pearlite colonies and pearlite ILS is achieved by increasing the Nb content, raising the cooling rate, and lowering the isothermal temperature, thereby increasing the content of precipitates and improving their mechanical properties.

Study of austenite grain growth and recrystallization behavior in pipeline steels containing niobium

Abstract The austenite grain growth and recrystallization behaviors of three pipeline steels with different Nb contents were investigated through reheating and thermal simulation compression experiments. The initiation conditions for dynamic and sub-dynamic recrystallization of austenite were analyzed, and sub-dynamic recrystallization equations in Avrami form were established. The influences of Nb content and deformation conditions on the evolution of grain size during austenite recrystallization was examined. The findings indicate that the austenite grain size of the three steels increases gradually with higher reheating temperatures, while the average grain size decreases with increasing Nb content. Sub-dynamic recrystallization initiation temperatures for the B150-steel, B145-steel, and 73-steel were found to be 920 °C for 10 s, 940 °C for 30 s, and 960 °C for 30 s, respectively. During high-temperature deformation, Nb in solid solution hindered recrystallization by impeding grain boundary and dislocation movement. At lower deformation temperatures, Nb(C, N) precipitation pinned grain boundaries and dislocations and consumed substantial free energy, thus competing with recrystallization. As Nb content increased, strain-induced precipitation became more pronounced, resulting in more effective inhibition of recrystallized grain growth.

Advancement of microstructural evolution and deformation mechanisms in AA6082 aluminum alloy under elevated-temperature tensile loading

This study explores the intricate interplay between strain-induced precipitation (SIP) and the underlying mechanisms that govern hot deformation in AA6082 aluminum alloy. Uniaxial tensile tests were conducted at elevated temperatures, ranging from 200 °C to 400 °C, and varied strain rates from 0.01 s−1 to 10 s−1. Employing advanced methodologies such as scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), energy dispersive X-ray spectrometry (EDS), and transmission electron microscopy (TEM), the research investigates the relationship between deformation, precipitation, and structural evolution. At lower strain rates, longer deformation times promote dynamic recrystallization, thereby promoting the growth of substructures with enhanced ductility. On the contrary, at higher strain rates (10 s−1), shorter deformation times inhibit such processes, resulting in a clear predominance of dislocation motion along specific slip systems and consequently influencing the mechanical response of the alloy. The results also reveal temperature-dependent deformation mechanisms, such as intragrain slip, continuous dynamic recrystallization (CDRX), and SIP phenomena, which influence the alloy's mechanical response. At 200 °C, prominent work hardening dominates, while 400 °C exhibits dynamic softening mechanisms. EBSD analysis elucidate temperature-specific deformation mechanisms, including intragrain slip at 200 °C and transitional phenomena at 300 °C. Microstructural analysis at 200 °C reveals the absence of needle- or rod-shaped precipitates. On the contrary, at 300 °C, the presence of β/β' precipitates significantly influences the nucleation of β'' precipitates at the grain boundaries. At 400 °C, substantial rod-shaped β' phase precipitates appear, demonstrating a complex interplay between diffusion mechanisms and strain-induced effects. In addition, the study also investigated the fracture behavior of aluminum alloy at different tensile temperatures, revealing the transition from transgranular fracture at 200 °C to intergranular fracture at 300 °C, as well as the shear effect of β/β' phase precipitates at this temperature. The findings provide a comprehensive understanding of the alloy behavior under diverse conditions, essential to optimize its processing parameters and mechanical properties.

A strong and ductile ferrite-based lightweight steel manufactured via high-temperature warm rolling process

A trade-off between strength and ductility is unavoidable in ferrite-based lightweight steels due to the presence of δ-ferrite, and improving the properties of such steels requires precise control of the retained austenite and the complete mobilization of multiple strengthening mechanisms. In this study, we obtain a ferrite-based lightweight steel with the chemical composition Fe-0.3C-2.8Mn-3.5Al-0.5Cr-0.2V by adopting a higher temperature warm rolling process, endowing the best comprehensive properties. The results demonstrate that multi-scale heterogeneous microstructures are built without additional recrystallization annealing under the higher temperature (>700 °C) warm rolling process. Meanwhile, a large amount of retained austenite, higher dislocation density and strain-induced vanadium carbide precipitation were obtained through the warm rolling process. As warm rolling refines austenite grains, Mn and Cr are further diffused and enriched, enhancing the chemical stability of the retained austenite. After low-temperature tempering, this warm-rolled steel shows excellent comprehensive properties, including a tensile strength of 1140 MPa and elongation of 30%. The enhanced strength-ductility is attributed to the higher stability of retained austenite, stable maintenance of dislocation density and the pinning effect of precipitation relative to dislocation lines. Furthermore, a stronger discontinuous yielding behavior of the warm-rolled and tempered steel was obtained, enhancing the overall strain.

Effect of Zr on static recrystallization of deformed austenite and strain-induced precipitation in Ti microalloyed steel

The static recrystallization and strain-induced precipitation behavior of Ti and Ti-Zr low carbon microalloyed steels were studied through isothermal stress relaxation experiments at different deformation temperatures (875–1025 °C). The precipitation kinetic curves of microalloyed carbides were obtained, and the effect of Zr on the precipitation kinetics of microalloyed carbides was analyzed. Two static recrystallization kinetic models were established, and the activation energies for static recrystallization of Ti steel and Ti-Zr steel were calculated to be 312.44 and 246.59 kJ/mol, respectively. The results indicate that the addition of Zr lowers the nose point temperature of the precipitation–time–temperature curve, shortens the incubation period for the nucleation of precipitates, promotes the nucleation of strain-induced precipitates in Ti microalloyed steel, and reduces the coarsening rate of precipitates particles by an order of magnitude. In addition, the addition of Zr also advances the end time of static recrystallization of deformed austenite, inhibits the growth of static recrystallization austenite grains in Ti steel during the isothermal process, and makes the austenite grains finer and more uniform.

Model for Prediction of the Size of Austenite Grains Upon Hot Deformation of Low-Alloyed Steels Taking into Account the Evolution of the Dislocation Structure

Abstract—A model is proposed to describe the behavior of the average size of austenite grains and the dislocation structure of low-alloyed steels during and after hot deformation. The model takes into account the processes of recovery, dynamic recrystallization of grains and normal grain growth, as well as the strain-induced precipitation of carbonitride phases and their evolution. The calculation results are compared with the experimental data available in the literature and their satisfactory agreement is shown.

Revealing the precipitation kinetics of multi-stage and multi-scale Ti-bearing precipitation in a 460 MPa grade HSLA steel

The multi-stage and multi-scale Ti-bearing precipitates, containing TiN, Ti(C, N), Ti4C2S2 and TiC, were systematically examined through experimental observations and our modified precipitation kinetic analyses. The result showed that cubic TiN (several microns) mainly precipitated in molten steel. After continuous casting, Ti(C, N) and Ti4C2S2 primarily precipitated in austenite, spanning 100–1000 nm in size. Upon subjected to severe rough rolling deformation, further precipitation of Ti(C, N) and Ti4C2S2 (tens of nanometers) appeared, accompanying with austenite recrystallization. During finishing rolling, recrystallized austenite grains were subdivided into multiple microbands, leading to an accumulation of deformation stored energy (DSE). The strain-induced precipitation (SIP) of spherical TiC particles (10–20 nm) distributed along microband walls, prior austenite grain boundaries, and even within the microbands. Subsequently, sequential matrix transformations, specifically ferrite (γ → α) and pearlite (γ → α + θ), were initiated during coiling. High-density TiC interphase precipitation occurred during the γ → α transformation, while a more dispersed, low-density TiC precipitation was observed after the γ → α + θ transformation. Kinetic analyses revealed that the nose temperature for Ti(C, N) precipitation in austenite was a minimum of 200 °C higher than that of Ti4C2S2. The DSE accelerated the TiC SIP with higher nose temperature in austenite during hot rolling. Moreover, kinetic analyses also implied that the migrating γ/α interface promoted faster TiC nucleation and growth relative to dislocation nucleation, and the relative precipitation time shortened more than 20 orders of magnitude. Furthermore, both the γ/α interface migrating velocity and the interface carbon content exhibited weak influence on the kinetics of interphase precipitation. However, the pearlite formation reduced the driving force of TiC precipitation, resulting in the TiC dispersed precipitation rather than TiC interphase precipitation.

Strain-induced precipitation behaviors of 7Mo super-austenitic stainless steel

Strain-induced precipitation (SIP) behaviors of 7Mo super-austenitic stainless steel (SASS) were studied by strain relaxation test at 850 °C. Our results reveal that sigma (σ) phases are the predominant SIP of 7Mo SASS, with the chemical formula of (FeNi) (CrMo). SIP first precipitates in granular shape at HAGBs, such as deformed grain boundaries (SIP-GBs), interfaces between deformation twin layers and matrix (SIP-TW), and HAGBs inside deformed grains (SIP-HAGBs). This is attributed to the ability of HAGBs for providing high deformation stored energy, nucleation sites, and efficient element diffusion channels. When the nucleation sites at HAGBs become saturated with increasing holding time, needle-like SIPs (SIP-NL) are precipitated along closely packed planes of γ-Fe matrix. The specific orientation relationships between SIP-NL and matrix, namely (−111)γ-Fe//(00–1)σ, [0–11]γ-Fe//[-110]σ or (-1-1-1)γ-Fe//(00–1)σ, [0–11]γ-Fe//[-110]σ, and the needle-like shape are contribute to minimizing interfacial energy and elastic strain energy of SIP, respectively, thereby promoting SIP-NL. The absence of SIP on dislocations can be attributed to the large critical nucleus size of σ phase (about 4.87 nm), which poses challenges for SIP nucleation through dislocation distortion energy. Mo is the controlling element for the nucleation and growth of SIP. SIP can promote cDRX through particle-induced nucleation (PSN) mechanism during the deformation process, while residual high-density dislocations around SIP can also promote cSRX during the holding process. During holding process, the boundaries of recrystallized grains can also serve as nucleation sites for SIP, thereby promoting SIP, and finally form a multi-layer structure of “σ phase/Recrystallization/σ phase”.

Microstructure evolution and precipitation behavior of hot-rolled high-strength Ti–Mo–V micro-alloyed steel

The microstructure evolution and precipitation behavior of hot-rolled Ti–Mo–V micro-alloyed high-strength steel processed at different final rolling temperatures (FRT) and coiling temperatures (CT) were investigated. The results indicated that the decrease of FRT (880 °C–820 °C) promoted the ferrite refinement and strain-induced precipitation in austenite, but it also led to the decrease of pearlite content, which finally led to a slight difference in properties, and CT obviously changed the phase component, grain size, and precipitation behavior. Appropriate reduction of the CT (650 °C–600 °C) could promote the precipitation of (Ti, Mo, V)C and refine ferrite grains, thus improving strength. As the CT further lowered to 550 °C, the precipitation hardening effect would be seriously lessened owing to the significant reduction of (Ti, Mo, V)C volume fraction, finally resulting in the loss of strength. The optimum mechanical properties were attained for the FRT850-CT600 sample, and the ultimate tensile strength (UTS), yield strength (YS), and total elongation (TE) were 908 MPa, 848 MPa, and 21.5 %, respectively, with precipitation hardening up to 383.51 MPa.

Strain-Induced Precipitation Behavior and Microstructure Evolution of Ti-V-Mo Complex Microalloyed Steel

Strain-Induced Precipitation Behavior and Microstructure Evolution of Ti-V-Mo Complex Microalloyed Steel

Effect of Deformation Conditions on Strain-Induced Precipitation of 7Mo Super-Austenitic Stainless Steel.

Strain-induced precipitation (SIP) behaviors of 7Mo super-austenitic stainless steel (SASS) under various deformation conditions were studied by stress relaxation tests. The research demonstrates that sigma phases are the primary SIP phases of 7Mo SASS. Generally, SIP is mainly distributed in granular shape at the boundaries of deformed grains or recrystallized grains, as well as around the deformed microstructure, such as deformation twin layers/matrix interfaces. The variation of deformation parameters can lead to changes in microstructure, therefore influencing the distribution of SIP. For instance, with the temperature increases, the SIP distribution gradually evolves from deformed grain boundaries to recrystallized grain boundaries. The average size of SIP increases with increasing temperature and strain, as well as decreasing strain rate. The SIP content also increases with increasing strain and decreasing strain rate, while exhibiting an initial rise followed by a decline with increasing temperature, reaching its maximum value at 850 °C. The presence of SIP can promote recrystallization by particle-induced nucleation (PSN) mechanism during the hot deformation process. Moreover, the boundaries of these recrystallized grains can also serve as nucleation sites for SIP, therefore promoting SIP. This process can be simplified as SIP→PSNRecrystallization→Nucleation sitesSIP. With the increase in holding time and the consumption of stored energy, the process gradually slows down, leading to the formation of a multi-layer structure, namely SIPs/Recrystallized grains/SIPs structure. Moreover, SIP at recrystallized grain boundaries can hinder the growth of recrystallized grains. Through this study, a comprehensive understanding of the SIP behaviors in 7Mo SASS under different deformation conditions has been achieved, as well as the interaction between SIP and recrystallization. This finding provides valuable insights for effective control or regulation of SIP and optimizing the hot working processes of 7Mo SASS.

A model for the competition between strain-induced precipitation and epitaxial growth in microalloyed austenite

A model has been developed for describing the competition between the formation of microalloyed carbonitrides by strain-induced precipitation (SIP) and by epitaxial growth on pre-existing TiN particles in γ-Fe. It is assumed that Nb and C/N atoms in the matrix will either feed the growth of pre-existing TiN precipitates or precipitate as new strain-induced particles. The model is successfully applied to the data set obtained by transmission electron microscopy (TEM) in a model alloy. Using this model, it is possible to estimate the effects of process parameters (T, applied strain), the number density of pre-existing TiN, and the Nb, C, N and Mn content on precipitate evolution and precipitation hardening. Notably, it is shown that the presence of a high number density of pre-existing TiN precipitates can suppress SIP. The conditions where epitaxial growth dominates and those in which strain-induced precipitation dominates are predicted and summarized in the form of processing maps.

Physical Metallurgy Guided Machine Learning for Strain‐Induced Precipitation of Nb (C, N) Based on the Orthogonalized Small Data

Strain‐induced precipitation (SIP) plays an important role in controlling the microstructure and properties of micro‐alloyed steels during hot rolling. However, due to lack of systematic experiments, the existing precipitation data are scarce and insufficient for accurate modeling of SIP behavior with good extrapolation. Herein, the data space of Niobium Carbonitride (Nb(C,N)) SIP kinetics is analyzed based on principle of orthogonal design, and the missing points in the orthogonal space are identified and supplemented in addition to the available data. The parameters in models for precipitation start and finish times are optimized by using the precipitation–time–temperature curves through genetic algorithm, and their relationships with compositions and processing conditions are established by support vector machine. Based on the orthogonally modified dataset, the machine learning (ML) models outperform the classical and ML models with the original data in terms of accuracy and are in good agreement with theoretical expectations. By using the new ML modeling, the evolution behavior of Nb (C, N) during hot deformation is predicted and verified with transmission electron microscope, and the influences of Nb content in steel, strain, strain rate, and the sensitivity of compositions and processing conditions on precipitation kinetics are quantitatively analyzed.

The effect of thermal and strain-induced aging on the mechanical behavior of room temperature ECAP processing of WE43 magnesium alloy

The WE43 magnesium alloy, in case of improved toughness, can be an appealing material for biomedical applications. The effects of equal-channel angular pressing (ECAP) and post-deformation aging (PDA) on the mechanical behavior of the WE43 alloy were investigated in this study. ECAP of WE43 magnesium alloy at room temperature is extremely challenging because of the insufficient number of slip systems. An optimized core–sheath configuration is proposed, which applies fully compressive stress on the WE43 alloy as the core, resulting in ECAP of the WE43 alloy at room temperature. Unprecedented strain-induced precipitation of both Mg41Nd5 and Mg24Y5 was observed owing to stored mechanical energy and temperature raise in the adiabatic shear bands during ECAP at room temperature. Moreover, the formation of oriented needle-like Mg3(Y, Nd) precipitates and partial recrystallization simultaneously increased the strength to 410 MPa and the strain to fracture to 11.4% after PDA. A combination of bimodal grain size distribution and a high volume fraction of precipitates increased the toughness to 38.96 MJ/m3 after ECAP and PDA.

Divergent interfacial behaviors of homo-/hetero-phase boundaries in a dual-phase eutectic high-entropy alloy

The interfacial structures and behaviors are critical in determining the material properties. Our study aims to investigate such unique interfacial structures and behaviors in multiphase systems involving complex compositions. Herein, we report the divergent interfacial behaviors of the L12–L12, B2–B2, and L12–B2 boundaries prepared via the bonding of AlCoCrFeNi2.1 eutectic high-entropy alloys (HEAs). Specifically, interfacial dynamic recrystallization (DRX) occurs in the L12–L12 boundary owing to the thermostrain-induced grain boundary evolution. In contrast, the bonding of the B2–B2 boundary may be realized by interface diffusion, and no evident DRX occurs owing to the small interfacial shear strain. The DRX grains only developed on the L12 side in the L12–B2 boundary because of the difference in the intrinsic structural traits between L12 and B2. The diffusion of elements contributed to the bonding of this dissimilar boundary. Moreover, a strain-induced B2II precipitation phenomenon surrounding the bonding interface was revealed because of the high defect-precipitation sensitivity of HEAs. The B2II particle precipitation depleted the Al and Ni within the matrix, leading to L12 disordering. The Zener pinning effect exerted by B2II precipitates was quantitatively evaluated by calculating the corresponding limited grain radius RL = 1.8 µm. This pinning effect of B2II precipitates and the sluggish diffusion effect may induce temperature-dependent DRX behaviors of the L12–L12 boundary. This study reveals the understanding of the unique interfacial behaviors of multiphase HEAs and provides new insights into the effects of multiple phases, complex composition, and interfacial precipitation on interfacial evolution.

Analysis of the Microstructure Development of Nb-Microalloyed Steel during Rolling on a Heavy-Section Mill.

It is not realistic to optimize the roll pass design of profile rolling mills, which typically roll hundreds of profiles, using physical modelling or operational rolling. The use of reliable models of microstructure evolution is preferable here. Based on the mathematical equations describing the microstructure evolution during hot rolling, a modified microstructure evolution model was presented that better accounts for the influence of strain-induced precipitation (SIP) on the kinetics of static recrystallization. The time required for half of the structure to soften, t0.5, by static recrystallization was calculated separately for both situations in which strain-induced precipitation occurred or did not occur. On this basis, the resulting model was more sensitive to the description of grain coarsening in the high-rolling-temperature region, which is a consequence of the rapid progress of static recrystallization and the larger interpass times during rolling on cross-country and continuous mills. The modified model was verified using a plain strain compression test (PSCT) simulation of rolling a 100-mm-diameter round bar performed on the Hydrawedge II hot deformation simulator (HDS-20). Four variants of simulations were performed, differing in the rolling temperature in the last four passes. For comparison with the outputs of the modified model, an analysis of the austenite grain size after rolling was performed using optical metallography. For indirect comparison with the model outputs, the SIP initiation time was determined based on the NbX precipitate size distribution obtained by TEM. Using the PSCT and the outputs from the modified microstructure evolution model, it was found that during conventional rolling, strain-induced precipitation occurs after the last pass and thus does not affect the austenite grain size. By lowering the rolling temperature, it was possible to reduce the grain size by up to 56 μm, while increasing the mean flow stress by a maximum of 74%. The resulting grain size for all four modes was consistent with the operating results.

Correlation between Precipitation and Recrystallisation during Stress Relaxation in Titanium Microalloyed Steel

This study investigated the correlation between strain-induced precipitation (SIP) and static recrystallisation (SRX) in Ti microalloyed steel during stress relaxation after controlled compression. The final compression temperature strongly influenced the order of SIP and SRX and thus the evolution of the austenite structure. Precipitation-time-temperature (PTT) curve obtained for the experimental steel exhibited an inverted “S” shape. A recrystallisation kinetics model revealed that SRX, which occurs preferentially above 940 °C, resulted in delayed subsequent SIP, thus causing deviation in the PTT curve from the typical ‘C’ shape. Below 940 °C, the fastest nose temperature for precipitation was located at 900 °C, and the precipitate was constituted by TiC particles with a NaCl-type FCC structure. The dynamic competition between SIP and SRX processes were evaluated by comparing the relative magnitude of the recrystallisation driving force and precipitation pinning force during stress relaxation, combined with the evolution of precipitate and austenitic structure. The results indicated that the plateau period occurred because of the precipitation pinning effect inhibited recrystallisation-induced austenite softening. However, the non-uniform distribution of SIP restricted the mobility of the boundaries to a portion of the austenite grains, resulting in abnormal grain growth during the plateau period.

Precipitation of homogeneous nanoscale HfRe2 in NiAl by strain-induced precipitation

The precipitation of homogeneous nanoscale HfRe2 in NiAl grains was achieved by strain-induced precipitation at 1000 °C with a strain rate of 0.001 s−1. HfRe2 could not be precipitated under separate heating at 1000 °C, as the deformation increased, HfRe2 began to precipitate and gradually increased in size due to Ostwald ripening. The increase in hardness confirmed the occurrence of precipitation processes. A detailed discussion of the phase composition of the precipitates and their orientation relationship with the matrix was performed. The lattice mismatch at the NiAl111//HfRe227¯55.36⊥HfRe227¯53 interface was calculated to be only 3.90% based on the Bramfitt two-dimensional lattice mismatch theory, which demonstrated that HfRe2 could precipitate with NiAl as a heterogeneous nucleus.

Static Recrystallization Behavior of Low-Carbon Nb-V-Microalloyed Forging Steel

Static recrystallization is a method of tailoring the microstructure and mechanical properties of steels, which is important for microalloyed forging steels as the hot deformation process significantly affects their mechanical properties. In this paper, the static recrystallization behavior of a low-carbon Nb-V-microalloyed forging steel was investigated by double-pass hot compression tests at deformation temperature of 800–1100 °C and interruption time of 1–1000 s. The static recrystallization fractions were determined using the 2% offset method. The static recrystallization activation energy and the static recrystallization critical temperature (SRCT) of the experimental steel were determined. When the deformation temperature was higher than the SRCT, the recrystallization fraction curve conformed to the Avrami equation. When the deformation temperature was below the SRCT, the recrystallization curve appeared to plateau, which was caused by strain-induced precipitation. Before and after the plateau, the static recrystallization kinetics still obeyed the Avrami equation.