Strain Hardening Effect Research Articles

Effect of twin assisted precipitation on the microstructure and mechanical properties of gradient structure Mg-Gd-Zn-Zr alloy

Nano-precipitation can effectively pin the dislocations and inhibit the dislocations’ motion, making precipitation strengthening one of the most crucial strengthening mechanisms in magnesium (Mg) alloys. Consequently, controlling the segregation of elements at the coherent interfaces to induce the phase precipitation, has become an innovative way of designing Mg alloys. In this study, a novel twin-precipitation composite gradient structure GZ151K (Mg-15Gd-1Zn-0.4Zr) alloy was prepared using ultrasonic surface rolling process (USRP) and heat treatment. The results indicated that the USRP-treated samples subjected to aging treatment demonstrated high thermal stability without significant twin degradation. Additionally, the twin boundaries and grain boundaries could act as the nucleated points for the (Mg, Zn)5Gd phases during the subsequent aging treatment, and further formed the twin-precipitation composite gradient structure. This unique composite gradient structure of alloys treated by USRP and aging treatment was caused by an extra promotion-precipitation strengthening mechanism. Under the effects of promotion-precipitation strengthening, strain hardening, and precipitation strengthening, the mechanical properties of the GZ151K alloy were significantly improved.

Modeling of acoustic field dependent tensile property for metal materials

Acoustic softening is a physical phenomenon with important application significance. Whether for ultrasonic-assisted metal processing or metal materials serving in the acoustic field environment, quantitative characterization of the impact of the acoustic field on material strength have important technological and engineering values. However, there are few reports on theoretical characterization models that can reveal the evolution of metal material strength with acoustic field. Based on the Force-Heat Equivalence Energy Density Principle, considering the equivalent relationship between acoustic energy and elastic deformation energy, the acoustic field dependent yield strength model of metal materials without fitting parameters is developed; considering the equivalent relationship between acoustic energy and elastoplastic strain energy, the acoustic field dependent ultimate tensile strength model considering strain hardening behavior is developed, and only the fitting parameters introduced in the constitutive equation are included in this model. The predicted results of both models are in good agreement with the experimental results. The quantitative effects of strength coefficient and strain hardening index on ultimate tensile strength under different acoustic fields is analyzed. The critical acoustic energy density is proposed to describe the point of abrupt change of ultimate tensile strength. Further, quantitative comparison of the influence on strain hardening effect and yield strength in different acoustic fields is conducted to explain the rapid decline of ultimate tensile strength. Finally, based on the above conclusions, some useful suggestions for safe use of metal materials under acoustic fields and ultrasonic-assisted machining are put forward.

Making a coherent L12-nano-precipitates-reinforced Ni-based alloy ultrastrong and ductile by constructing dual heterogeneous structures

It is known that inhibiting rapid decline of strain hardening is crucial in enhancing uniform ductility under uniaxial tension stress for metallic materials with high yield stress. In this study, a high-mechanical-response Ni-based alloy was introduced by fabricating a dual-heterogeneous structure allowing to provide improved strain-hardening capability at both ambient and cryogenic temperatures. Especially at cryogenic temperature, an exceptional strength-ductility synergy with yield strength of 1.85 GPa and ductility of 24% can be achieved, accompanied by a distinctive five-stage strain-hardening response. In such a case, deformation twinning behavior was activated successfully to assist the strain hardening in the Ni base alloy although precipitation-hardening effect was available. Our work sheds light on the strain hardening effect assisted by twinning previously unexpected in coherent precipitation-hardened Ni base alloys, and hence represents a promising route for improving uniform ductility of Ni base alloys with high yield strength.

Reinforcement effect of cutting process on machined surface quality and performance of aviation aluminum alloy 7075 based on Oxley-Welsh theory

Aiming at the difficult problem of regulating the mechanical properties of the machined surface in the dry cutting of aviation aluminum alloy 7075, and the deviation of the solution caused by the idealized assumption of stress-strain in the shear zone in the previous cutting models, the effect of cutting parameters on the average width of the shear zone and stress-strain behavior of aviation aluminum alloy 7075-T651 in the dry turning process, and the effect of strain-hardening behavior on the cutting model were studied based on the Oxley-Welsh theory. In addition, relationship models between shear flow stress and hydrostatic stress in cutting zone, hydrostatic-shear difference of material unit, microhardness of machined surface, as well as surface roughness were established, which reasonably explains the size effect and strain-hardening effect in the shear zone of workpiece material during dry turning of 7075-T651 aluminum alloy. The results showed that the slope K of the relationship model between shear flow stress and hydrostatic stress is the result of the combined effect of the size effect and the strain-hardening effect in the shear zone of workpiece material. When the 7075-T651 aluminum alloy is produced under the cutting conditions of cutting velocity vc = 240 m/min, feed rate f = 0.05 mm/r, and cutting depth ap = 0.15 mm, the machined workpiece had the best uniform plastic deformation, relatively highest surface hardness, up to 174.1 HV, relatively best surface quality, with roughness up to 0.78 μm, and relatively strongest load-bearing capacity in the service process.

Molecular dynamics study on dynamic mechanical behaviour of FeCoCrCuNi high entropy alloy

ABSTRACT In this paper, molecular dynamics simulation method was used to establish the atomic model of high entropy alloy. The effect of strain rate on the microstructure evolution and dislocation motion of FeNiCoCrCu high entropy alloy was studied by applying tension and compression loads at different strain rates. The results show that the stress–strain curve of FeNiCoCrCu high entropy alloy presents three stages of elastic deformation, yield and plastic deformation under high strain rate. Under tensile load, Frank dislocation causes plastic deformation of the material, and the dislocation reaction between Shockley dislocation and Hirth dislocation generates Stair-rod dislocation. The mechanism of stress relaxation of materials under compression load is the formation of stacking faults. One of the mechanisms of strain hardening of materials is the formation of twins. In addition, stacking faults intersect with each other to produce dislocation reactions, which generate Stair-rod dislocations, maintaining the development of strain hardening effect.

Multi-objective optimization of high performance concrete columns under compressive loading with potential applications for sustainable earthquake-resilient structures and infrastructures

High performance column composites are multifunctional composites designed to improve resilience of structures and infrastructures to natural and unforeseen multiple loads during service. As a result of their superior mechanical performance, high performance column composites have been found attractive to improve resilience of medium and high-rise buildings as well as long-span structures and infrastructures in earthquake-prone regions. Scientometric analysis revealed limitations of traditional design standards and inadequate earthquake engineering to reduce collosal damage during seismic impact and the need for investment in alternative green energy to reduce anthropogenic-induced earthquakes linked to oil and gas projects. High performance CFRP (carbon fibre reinforced polymer) composite was investigated as potential laminate reinforcement and confinement for recycled concrete column using performance-based Taguchi-Response surface methodology optimization. Though columns wrapped with two layers CFRP confinement and reinforced with internal laminate CFRP reinforcement obtained higher maximum load and favourable failure mode, the optimized result, which comprises column confined with two layers of external CFRP confinement only, obtained 36.3% and 36.19% greater fracture toughness and fracture energy respectively, 1.4 times better displacement ductility index, 2.78 times strain ductility index and comparable load capacity. The superior mechanical performance of high performance recycled concrete column composite and favourable failure mode was attributed to strain hardening effect which depends on the CFRP confinement. Further studies are required to improve the mechanical performance and failure mode of high performance column composite for construction of resilient structures and infrastructures in the built environment.

Scaling of bi-material sandwich panels subjected to impact loadings

Scaling is a widely used concept in impact and explosion engineering which is mainly utilized to predict the response behaviour of large-scale mechanical structures by conducting experiments on scaled trial models. However, the practical application of currently available conventional scaling methodologies for impact and explosive processes are significantly restricted by their inability to properly capture the scale effects of strain rate and strain hardening. Also, they are suffering from an insufficient number of independent degrees of freedom. Furthermore, the zeroth-order finite similitude theory, which can annihilate the non-scalability of rate and hardening effects, doesn’t provide us with efficient scaling methods when the investigated structure is made out of different materials. More precisely, the zeroth-order finite similitude theory and the classical dimensional analysis, which are suffering from a limited number of independent degrees of freedom, cannot scale the elastic-plastic behaviour represented by different parts of a structure made out of different materials. In other words, classical scaling methodologies including dimensional analysis and even the zeroth-order finite similitude theory cannot fix two different features having the same unit using different degrees of freedom, which make them useless for structures made of more than one material such as bi-material sandwich panels. In the presented paper, a new scaling methodology is developed based on the recently proposed first-order finite similitude theory which for the first time enables us to capture the rate dependent plastic behaviour of an impacted structure made out of two different materials. A sandwich panel made of two different materials which is subjected to an impact loading is considered as the case study in order to investigate the efficiency of the proposed first-order based scaling technique. The numerical results are determined using Abaqus finite element software in which the Johnson-Cook constitutive equation is utilized to take into account the rate and hardening effects on the initial yield stress. The results reveal that the behaviour of impacted full-scale bi-material sandwich panels can be predicted with a high accuracy when the extra degree of freedom provided us with the first-order finite similitude (i.e. R1) is set to vary between −1 and 1 (i.e. [Formula: see text]). Furthermore, it is found that the pure mechanical and thermo-mechanical behaviour of the impacted core honeycomb are highly accurately predicted using scaled-down trial models which are made from dissimilar materials and designed based on the zeroth-order finite similitude theory.

Experimental characterization and numerical modeling of the influence of a proof load on the fatigue resistance of welded structures

The influence of a proof load, or an initial overload, on the fatigue resistance of welded structures is investigated in this study. Arc welded stiffeners made of S355 steel are considered and fatigue-tested in as-welded and proof-loaded conditions. X-ray diffraction analyses are carried out to evaluate the influence of a proof load on the residual stress field. To better understand the role of a proof load on the mechanical fields in the stress concentration zones, a numerical approach based on elasto-plastic finite element analyses is proposed. The methodology includes a non-local multiaxial fatigue criterion, which integrates a strain hardening contribution, that makes it possible to estimate the number of cycles to failure. The comparison between experimental and numerical results indicates that the beneficial effect of a proof load on the fatigue resistance can be mainly attributed to residual stress and strain hardening effects. The final result is a master SN curve adapted to the fatigue design of stiffener structures, tested under different loading conditions.

Microstructure and strength of diffusion bonding W alloy/304 stainless steel joint using a Cu interlayer

To realize the high-performance diffusion bonding of W alloy (90 W-7Ni-3Cu) with 304 stainless steel (304SS), the microstructure and mechanical properties of the solid diffusion bonding joints of W alloy and 304SS with a pure Cu interlayer were conducted at 900 °C, 20 MPa and 2 h. The results showed that the solid diffusion bonding with a Cu interlayer, can achieve a reliable bonding between the W alloy and 304SS. Furthermore, all the interfaces have excellent bonding through mutual diffusion of atoms at the W/Cu and Cu/304SS interfaces. No intermetallic compounds, or other brittle phases were formed in the bonding area. At the W/Cu interface, the interplanar spacing increased due to the diffusion of Cu atoms into the W lattice. Moreover, a nano-indentation test across the joint interfaces demonstrated the effect of solid-solution strengthening and strain hardening in the 304SS/Cu diffusion zone. The tensile strength of the joint was as high as 265 MPa, which was about 58% higher than for the joint without a Cu interlayer. The fracture analysis showed that the mixed fracture mode of plastic fracture and intergranular fracture occurred in the Cu interlayer and at the Cu/304SS interface. Mechanical tension tests revealed the enhanced strength of the joint with a Cu interlayer.

Strain-dependent assessment of dough's polymer structure and functionality during the baking process.

During the baking process, the functionality of the heterogeneous dough matrix changes as the composing polymers experience conformational transition processes. The thermally induced structural changes affect the involvement and functionality of the polymers in the dough matrix. With the main hypothesis being that different types and magnitudes of strain exerted during the measurement would provide information on different structural levels and interactions, SAOS rheology in multiwave mode and large deformation extensional rheometry were applied to two microstructurally different systems. The functionality of the two systems, a highly connected standard wheat dough (φ ≈ 1.1) and an aerated, yeasted wheat dough (φ ≈ 2.3), depicting limited connectivity and strength of interactions, was accessed under different deformations and types of strains. Applying SAOS rheology, starch functionality prevailed on the behavior of the dough matrix. In contrast, gluten functionality prevailed the large deformation behavior. Using an inline fermentation and baking LSF technique, the heat-induced gluten polymerization was shown to increase strain hardening behavior above 70°C. In the aerated system, the strain hardening effect became already evident under small deformation testing, as the expansion of gas cells caused a pre-expansion of the gluten strands. The expanded dough matrix of yeasted dough was further shown to be substantially subjected to degradation once the network reached beyond its maximal gas holding capacity. Using this approach, the combined impact of yeast fermentation and thermal treatment on the strain hardening behavior of wheat dough was revealed for the first time by LSF. Furthermore, the rheological properties were successfully linked to oven rise behavior: a decreasing connectivity combined with the initiation of strain hardening by fast extension processes occurring in the yeasted dough matrix during the final baking phase was linked to limited oven rise functionality prematurely around 60°C.

Evolutions of microstructure and mechanical properties of copper/SS304L composite micro channels during micro rolling

Manufacturing metallic micro channels is a critical issue in micro-electromechanical systems (MEMS), such as micro reactors, micro heat exchangers, micro heat sinks, and fuel cell bipolar plates. An ultra-thin metal foil rolling for the fabrication of micro composite channels was proposed in this study, which is able to improve product functions and reduce operational costs. Copper/SS304L composite foils after annealing at 900 °C were used to form micro channels under different rolling reductions (29.1%, 43.8% and 50.0%), in which the thickness of copper and SS304L are 0.3 mm and 0.1 mm, respectively. Accordingly, the microstructure evolution, material deformation behaviours and mechanical properties of the samples after micro rolling were investigated. From the characterisation of the micro channel region on the copper side, a double fibre texture is produced parallel to the rolling reduction, including a relatively strong <111> fibre and a weak <100> fibre. Moreover, a relatively strong <111> fibre and three weak <100>, <110> and α fibres along the rolling direction can be identified on the SS304L side. The hardness of copper and SS304L increases with the increase of rolling reduction, due to the strain-hardening effect for copper, and accumulated dislocation and formation of strain-induced α’ martensite for SS304L during micro rolling, respectively. It is noted that in the ridge region for all the samples, the left fillet is harder compared to the right fillet, indicating the asymmetry of material flow.

Experimental study on the mechanical performance of tyre encased soil elements for structural wall applications

Tyre-encased-soil elements (TESEs) are segmental units made by compacting soil inside the cavity of EOL tyres. The TESEs can function similarly to bricks to build masonry walls or other load-bearing structures. Tyre walls built of TESEs have proven successful architectural and structural performance. However, the mechanical properties of TESEs have not been scientifically investigated in the past, and insufficient evidence restricted TESEs’ further application as structural components. This project attempted to fill the gap by studying the performance of TESEs subject to axial compressive loads through both laboratory experiments and analytical analysis. Soils with different properties were used in the experiments to quantify their influence on the TESEs performance. It was found that within the range of loading applied in this study, no abrupt failure was observed on the tested TESEs. The axial stress-strain relationship followed an exponential form, possibly due to the strain-hardening effect brought in by the densification of encased soil and increased confinement support from the tyre reinforcement. The encased soil’s density had a significant influence on the load-deformation behaviour of the TESEs. However, the load-carrying capacities were not highly sensitive to the soil type and its moisture content. An analytical model was proposed for capturing the axial and radial strain of TESEs under applied axial loads with a reasonable accuracy. In material characterisation, the strength of EOL tyres captured in the inflation tests were significantly larger than those obtained from direct tensile tests, which revealed the cut tyre strip could not capture the synergic effect of the embedded tyre reinforcement composites in a representative manner. The results of this study can be used by built environment professionals to design and analyse the performance of tyre encased soil and tyre walls.

3D FEM Simulation of Titanium Alloy (Ti6Al4V) Machining with Harmonic Endmill Tools

AbstractUsually, end milling operations have been carried out using conventional uniform helix tools with fixed helix angles. Thus, many studies have been conducted to study the effects of these tools on the thermomechanical properties of a milling process. Recently, there have been works that point to the benefits of using harmonic endmills. Harmonic endmills consist of cutting edge profiles that have continuously harmonically varying helix angles. The variation is described using a harmonic function of axial position (elevation) of points on the cutting edge. In this work, a 3D finite element simulation using ABAQUS, is carried out for the complex milling process of Titanium alloy Ti6Al4V. The envelope of the harmonic tool is first generated using a set of MATLAB codes and stored in a Standard Triangle Language (.stl) format. The machine tool is introduced into an FEM program which has been designed to provide for dynamic effects, thermo‐mechanical coupling, material damage law and the criterion for contact associated with the milling process. A Johnson‐Cook material constitutive equation which combines the effects of strain hardening, strain softening, and temperature softening is used. To account for the chip separation criterion, the Johnson Cook damage evolution equation is used. The milling process simulation for Ti6Al4V is then carried out. In the end, the stress distribution and the cutting forces are obtained.

The Effects of Microstructure on the Dynamic Mechanical Response and Adiabatic Shearing Behaviors of a Near-α Ti-6Al-3Nb-2Zr-1Mo Alloy

The formation and evolution of adiabatic shear behaviors, as well as the corresponding mechanical properties of a near-Ti-6Al-3Nb-2Zr-1Mo (Ti-6321) alloy during dynamic compression process, were systematically investigated by the split Hopkinson pressure bar (SHPB) compression tests in this paper. Ti-6321 samples containing three types of microstructures, i.e., equiaxed microstructure, duplex microstructure and Widmanstätten microstructure, were prepared to investigate the relationship between microstructures and dynamic mechanical behaviors under different strain rates in a range from 1000 s-1 to 3000 s-1. It was found by the dynamic strain-stress relation that the Ti-6321 alloys containing equiaxed microstructure, duplex microstructure and Widmanstätten microstructure all exhibited a strong strain-hardening effect. The samples containing equiaxed microstructure exhibited a larger flow stress than samples containing duplex microstructure and Widmanstätten microstructure. The adiabatic shearing behaviors in Ti-6321 alloy are significantly influenced by different types of microstructures. The formation of adiabatic shearing bands occurs in equiaxed microstructure when the strain rate is increased to 2000 s-1. The adiabatic shear bands are formed in duplex microstructure when the strain rate reaches 3000 s-1. However, the initiation of adiabatic shear bands is found in Widmanstätten microstructure under the strain rate of 1000 s-1. The Widmanstätten microstructure shows a larger sensitivity to adiabatic shearing than the equiaxed microstructure and duplex microstructure samples.

Axial compressive performance of seawater sea sand concrete-filled CFRP-stainless steel tube short columns

In order to improve the bearing capacity and durability of thin-walled stainless steel structures, the internal and external walls of stainless steel tube were pasted with CFRP to form CFRP-stainless steel composite tube, and the axial compressive mechanical properties of seawater sea sand concrete-filled carbon fiber-reinforced polymer (CFRP)-stainless steel tube (SCSST) short columns were investigated in this study. Twenty-one specimens were tested with the CFRP pasting methods and the number of CFRP pasting layers as the variation parameters. The results indicate that the failure modes of the specimens without CFRP and internal CFRP specimens were shear damage, while the external CFRP specimens were waist drum damage, all CFRP were fractured. CFRP and stainless steel tube had good cooperative performance. The bearing capacity, damage and energy absorption suppression of specimens were improved with the increase of CFRP layers, but the ductility and initial stiffness increased first and then decreased. With the same layers of CFRP, the mechanical properties of internal CFRP specimens were better than those of external CFRP specimens, and the ultimate bearing capacity could be increased by 5.5% and 8.8%. Finally, the strain-hardening effect of stainless steel was considered and a bearing capacity calculation formula of SCSST short columns based on the limit balance method was proposed, and 115 data samples were collected to verify the calculation formula.

Microstructure, mechanical properties, and strain rate sensitivity of vacuum arc melted CoCrNi medium entropy alloy

Vacuum arc melting is a prevalent and low-cost technique to synthesize several metals and alloys. This study reports the microstructure, mechanical properties, and high strain rate testing of vacuum arc melted CoCrNi Medium Entropy Alloy (MEA). CoCrNi is a popular MEA owing to its better combination of strength and ductility, and the alloy also exhibits superior fatigue properties to the well-known first-generation CoCrFeMnNi high entropy or Cantor alloy. The CoCrNi MEA is found to be a single-phase face-centered cubic (fcc) solid solution and microstructural investigation revealed near-equiaxed coarse grains. Since strain hardening is an important mechanism for strengthening of CoCrNi at higher strains, the high strain rate tests are performed at strain rates of 103, 203, and 303 S-1. The strain hardening effect is dominant at higher strain rates, and a positive strain rate sensitivity of 0.256 ± 0.03 is observed.

A Microphysical Model of Rock Friction and the Brittle‐Ductile Transition Controlled by Dislocation Glide and Backstress Evolution

AbstractRate‐ and state‐friction (RSF) is an empirical framework that describes the complex velocity‐, time‐, and slip‐dependent phenomena observed during frictional sliding of rocks and gouge in the laboratory. Despite its widespread use in earthquake nucleation and recurrence models, our understanding of RSF, particularly its time‐ and/or slip‐dependence, is still largely empirical, limiting our confidence in extrapolating laboratory behavior to the seismogenic zone. While many microphysical models have been proposed over the past few decades, none have explicitly incorporated the effects of strain hardening, anelasticity, or transient elastoplastic rheology. Here we present a new model of rock friction that incorporates these phenomena directly from the microphysical behavior of lattice dislocations. This model of rock friction exhibits the same logarithmic dependence on sliding velocity (strain rate) as RSF and displays a dependence on the internal backstress caused by long‐range interactions among geometrically necessary dislocations (GNDs). Changes in the backstress (internal stress) evolve exponentially with plastic strain of asperities and are dependent on both the current backstress and previous deformation, which give rise to phenomena consistent with interpretations of the “critical slip distance,” “memory effect,” and “evolution effect” of RSF. The rate dependence of friction in this model is primarily controlled by the evolution of backstress and temperature. We provide several analytical predictions for RSF‐like behavior and the “brittle‐ductile” transition based on microphysical mechanisms and measurable parameters such as the GND density and strain‐dependent hardening modulus.

Multistage strain-hardening behavior of ultrastrong and ductile lightweight refractory complex-concentrated alloys

Lightweight high-entropy alloys or complex-concentrated alloys have demonstrated great potential for engineering applications due to their high strength and lightweight. However, a weak strain-hardening ability and a limited tensile ductility remain their major hindrance. Here, a multistage strain-hardening effect is developed to ensure a high strength and still a sufficient ductility in a rolled and annealed (Ti44V28Zr14Nb14)98.5Mo1.5 (at.%) lightweight refractory complex-concentrated alloy (M1.5A-LRCCA). This multistage strain-hardening behavior is related to the microstructure and the corresponding initial average dislocation density and distribution by comparison with rolled and annealed Ti44V28Zr14Nb14 (M0-LRCCA) and as-cast (Ti44V28Zr14Nb14)98.5Mo1.5 (M1.5C-LRCCA). The microstructure, with homogeneously distributed submicron precipitations, a moderate initial average dislocation density, and uniform dislocation distribution (e.g., M1.5A-LRCCA), is susceptible to producing various deformation substructures, such as dislocation substructures (slip bands, Taylor lattices, microbands, DDWs), shear bands, and deformation twins, which results in the multistage strain-hardening behavior. This method of achieving multistage strain hardening behavior through a microstructure modulation is significant for engineering applications of lightweight high-entropy alloys or complex-concentrated alloys, and it might be extended to other lightweight and high-strength alloys.

A new analytical-numerical model for contact problem counting asperities and strain hardening effects

The roughness effects on the wheel-rail contact problem is an essential topic. In this paper, a new analytical-numerical model has considered assessing the specifications of a rough surface contact problem. The new model includes asperities and strain hardening effects together. Consideration of these assumptions is more realistic in comparison to similar simplified works. In this work, the effects of material properties variation on a contact problem realize. Besides, considering the strain hardening effects, the contact results for wheel-rail material are obtained. The contact characteristics variations versus separation, such as contact force, contact stiffness, and contact area, are shown in semilogarithmic diagrams considering different surface roughnesses and hardening parameters. The new model results show the significant influence of the assumed hypothesis on the contact characteristics.

Hot Tensile Deformation Behavior and Constitutive Models of GH3230 Superalloy Double-Sheet.

In this paper, the hot tensile deformation of a GH3230 superalloy double-sheet was conducted under deformation temperatures ranging from 1123~1273 K and strain rates ranging from 0.001~0.2 s-1. The flow behavior of the GH3230 superalloy double-sheet was analyzed in detail. The hot tensile deformation process of the GH3230 superalloy double-sheet includes four stages of elastic deformation, strain hardening, steady state and fracture. The true stress decreases with the increasing deformation temperature and decreasing strain rate. The variation of the strain rate sensitivity index and strain hardening index with processing parameters were discussed. The average apparent activation energy for hot tensile deformation is 408.53 ± 46.96 kJ·mol-1. A combined Johnson-Cook and Hensel-Spittle model considering the couple effect of strain hardening, strain rate hardening and thermal softening was established to describe the hot tensile behavior of the GH3230 alloy double-sheet. Compared to Johnson-Cook model and Hensel-Spittle model, this model has the highest predicting accuracy. The average absolute relative error of true stress between the experimental and the predicted is only 2.35%.