Investigation of the Plastic Properties of Certain Ferrous and Nonferrous Materials at High Temperature

Plastic properties of certain carbon steels, brasses, copper, and aluminum are determined between room and recyrstallization temperatures. The investigations are carried out using the tension test conducted in a specially constructed furnace. Equivalent-stress, equivalent-strain curves and plastic anisotropy parameters are obtained. The equivalent-stress, equivalent-strain curves are then fitted to an empirical equation σ¯ = A(B + ε¯)n by a computer program employing a numerical gradient method. The results show that equivalent stress decreases as the temperature increases, and it increases as the strain-rate increases. Materials obtained as round bars show very little plastic anisotropy in their transverse planes whereas materials in the form of sheets have pronounced anisotropy. Plastic anisotropy decreases as temperature increases. The results obtained and techniques used may prove to be useful for designers of metal forming equipments, and researchers in the area of plasticity.

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Effect of Strain Hardening Laws on Solution Behavior Near Frictional Interfaces in Metal Forming Processes: A Simple Analytical Example

Processes ◽

10.3390/pr8111471 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1471

Author(s):

Sergei Alexandrov ◽

Elena Lyamina ◽

Pierre-Yves Manach

Keyword(s):

Strain Hardening ◽

Metal Forming ◽

Equivalent Stress ◽

Qualitative Difference ◽

Closed Form Solution ◽

Equivalent Strain ◽

Form Solution ◽

Thin Layers ◽

Qualitative Behavior ◽

Constitutive Parameters

The main objective of the present paper is to compare, by means of a problem leading to a closed-form solution, the qualitative behavior of solutions based on three strain hardening laws: Swift’s law, Ludwik’s law, and Voce’s law. The boundary value problem involves the maximum friction law as one of the boundary conditions. Such features of the solutions as nonexistence and singularity are emphasized. An important feature of Swift’s and Ludwik’s laws is that the equivalent stress approaches infinity as the equivalent strain approaches infinity. On the contrary, Voce’s law involves saturation stress as one of the constitutive parameters. This qualitative difference in the equivalent stress behavior as the equivalent strain approaches infinity results in the qualitative difference in solutions’ behavior. In particular, Swift’s and Ludwik’s hardening laws are compatible with the regime of sticking independently of other conditions. In the case of Voce’s law, the solution under sticking conditions may break down. Moreover, Voce’s law predicts intensive strain levels near the friction surface at sliding, and the other strain hardening laws do not. Thin layers of intensive plastic deformation often occur near frictional interfaces in metal forming processes. Voce’s law predicts the occurrence of such layers without any additional assumptions.

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Investigation on Ultra-high Temperature Forging Process Based on DEFORM-3D Simulation

10.21203/rs.3.rs-196059/v1 ◽

2021 ◽

Author(s):

Wu Yong-qiang ◽

Wang Kai-kun

Keyword(s):

High Temperature ◽

Equivalent Stress ◽

Strain Curve ◽

Green Manufacturing ◽

Equivalent Strain ◽

Temperature Fields ◽

Forging Process ◽

Reheating Process ◽

Deform 3D ◽

Ultra High Temperature

Abstract Green manufacturing and forming technology is becoming increasingly important in modern industry. In this study, a new forging technology with the ultra-high temperature demoulding is introduced, in which conventional reheating process could be avoided. The DEFORM-3D software simulated the forging process and the temperature fields were obtained. The traditional forging process was simulated when the initial forging temperature was 1220℃. The highest temperature of the ingot in the new forging technology was about 200℃ higher than that of the traditional forging process. We cut the ingot longitudinally along the centerline. Nine points on the axis of the cutting plane and nine points on the radial direction were selected. The equivalent stress and the equivalent strain of these points were compared respectively under the two forging processes by using the particle tracking method. The variation laws of the equivalent stress and the equivalent strain with the reduction were obtained. According to the variation laws, the typical points which were easy to crack under two different forging processes were found. Based on the flow stress-strain curve calculated by the software JMatPro®, the new forging technology could avoid hot cracking.

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S-TEN1

Alloy Digest ◽

10.31399/asm.ad.sa0550 ◽

2005 ◽

Vol 54 (8) ◽

Keyword(s):

Corrosion Resistance ◽

High Temperature ◽

Physical Properties ◽

Tensile Properties ◽

Carbon Steels ◽

Dew Point ◽

Steel Alloy ◽

Temperature Performance ◽

Nippon Steel Corporation ◽

Steel Corporation

Abstract S-TEN1 is a steel alloy containing copper and antimony to make it more resistant to dew-point corrosion than conventional carbon steels. It is used as tubing in economizers. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming and joining. Filing Code: SA-550. Producer or source: Nippon Steel USA Inc., Nippon Steel Corporation.

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Research on NX-Based Progressive Die Design

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.602-604.1818 ◽

2012 ◽

Vol 602-604 ◽

pp. 1818-1821

Author(s):

Jun Liu ◽

Cong Dong Ji

Keyword(s):

Design Method ◽

Equivalent Stress ◽

Equivalent Strain ◽

Die Design ◽

Support Design ◽

Stress Resilience ◽

Progressive Die ◽

Key Technology ◽

Product Manufacturing ◽

Progressive Die Design

Progressive die has been widely used in product manufacturing field. This paper proposed a NX-based computer server support design method. The equivalent stress, resilience, equivalent strain, attenuation, and forming were analyzed in detail. The key technology of confirming blank dimension and stock layout of server support were explicated clearly.

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Elasto-plastic and creep behaviour of axially loaded, shouldered tubes

The Journal of Strain Analysis for Engineering Design ◽

10.1243/03093247v151021 ◽

1980 ◽

Vol 15 (1) ◽

pp. 21-29 ◽

Cited By ~ 18

Author(s):

R J Dawson ◽

H Fessler ◽

T H Hyde ◽

J J Webster

Keyword(s):

Finite Element ◽

Creep Behaviour ◽

Equivalent Stress ◽

Strain Curve ◽

Equivalent Strain ◽

Uniaxial Tensile ◽

Plastic Strain Increment ◽

Axially Loaded ◽

Initial Strains ◽

Creep Strains

This paper compares the finite element predictions of elasto-plastic and creep behaviour with experimental data for axially loaded, shouldered tube models. Four shouldered tube models were made of a lead alloy and tested at 61°C, using strain gauges to measure the elasto-plastic and creep strains in the plain tube and fillet regions of the models. Instantaneous stress-strain and creep data were obtained from strain-gauged, uniaxial tensile specimens. The finite element solutions are based on the incremental Prandtl-Reuss equations. The elasto-plastic iterative solutions use a ‘negative gradient’ from the calculated point to the equivalent stress-equivalent strain curve to get the next estimate of the plastic strain increment. A time incremental method is used to obtain the creep solutions. Tests with the mean tube stress below, at and above the yield stress showed very good agreement between prediction and measurement of initial strains in the fillets. Differences between predictions and measurements of creep strains are attributable to cast-to-cast variations.

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The effect of plastic anisotropy on flange-wrinkling behaviour during sheet metal forming

International Journal of Mechanical Sciences ◽

10.1016/0020-7403(68)90083-0 ◽

1968 ◽

Vol 10 (9) ◽

pp. 681-694 ◽

Cited By ~ 16

Author(s):

H. Naziri ◽

R. Pearce

Keyword(s):

Sheet Metal ◽

Sheet Metal Forming ◽

Metal Forming ◽

Plastic Anisotropy ◽

Flange Wrinkling

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Analysis of the stress-strain state of a vertical ground electrode system for permafrost soils under pushing loads

Oil and Gas Studies ◽

10.31660/0445-0108-2021-1-77-89 ◽

2021 ◽

pp. 77-89

Author(s):

I. S. Sukhachev ◽

P. V. Chepur ◽

A. A. Tarasenko ◽

A. A. Gruchenkova ◽

Yuhai Guan

Keyword(s):

Equivalent Stress ◽

Side Surface ◽

Metal Structure ◽

Vertical Displacement ◽

Soil Mass ◽

Electrode System ◽

Plastic Properties ◽

Design Scheme ◽

Permafrost Soils ◽

Vertical Ground

The article proposes the design, design scheme and model of a vertical ground electrode system with lobe lugs for permafrost soils. The model was implemented using the ANSYS software. In the design scheme, the soil — ground electrode system is taken into account, the elastic-plastic properties of the soil are taken into account by the Drucker — Prager model. When modeling the work of the foundation soils, the Mises strength condition was adopted, according to which the equivalent stress is calculated under the condition of the material hydrostatic compression. The following boundary conditions are accepted: a cylinder-shaped soil mass is rigidly fixed along the lower face and along the side surface of the cylinder. Calculations are made for 5 standard sizes of grounding conductors. Maps of the distribution of stresses in the metal structure of the ground electrode (the rod and petals-emphasis) are received, the movements of the ground electrode in the soil mass are determined. The dependences between the maximum equivalent stresses in the ground electrode lobes and the value of vertical displacement in the ground base are established, as well as the amount of movement of the earthing pad, at which the effective equivalent voltages reach critical values in the area where the paddles are adjacent to the rod.

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Study on Superalloy Tube Extrusion Process Using Finite Volume Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.572.267 ◽

2012 ◽

Vol 572 ◽

pp. 267-272

Author(s):

Yi Lun Mao ◽

Qing Dong Zhang ◽

Chao Yang Sun ◽

Xiao Feng Zhang

Keyword(s):

Mathematical Model ◽

High Temperature ◽

Finite Volume Method ◽

Finite Volume ◽

Extrusion Process ◽

Equivalent Strain ◽

High Temperature Alloy ◽

Squeeze Pressure ◽

Tube Extrusion ◽

Volume Method

In this paper, complexity of the process of high temperature alloy tubing extrusion is studied using the Finite Volume Method (FVM). We establish mathematical model of high temperature alloy tube extrusion process by using the Finite Volume Method. We develop the simulation program by the control equation of the Finite Volume Method and numerical simulation of the key technologies of the axisymmetric problem in cylindrical coordinates. Inconel690 high temperature alloy tubing extrusion process, for example, we got the squeeze pressure in the steady-state extrusion, Velocity field and the corresponding equivalent strain rate field. By comparing the results obtained by the finite volume method and simulation results from Finite Element Method (FEM) software on DEFORM-2D, we find our mathematical model on high temperature alloy tubing extrusion process is reasonable and correct.

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White-light speckle image correlation applied to large-strain material characterization

European Journal of Computational Mechanics ◽

10.13052/ejcm.18.377-392 ◽

2009 ◽

pp. 377-392

Author(s):

Giovanni B. Broggiato ◽

Luca Cortese

Keyword(s):

Material Characterization ◽

Plastic Material ◽

Large Strain ◽

Equivalent Stress ◽

Tensile Tests ◽

Equivalent Strain ◽

Image Correlation ◽

Plastic Behavior ◽

Full Field ◽

Measurement Devices

In experimental mechanics, the possibility of tracking on component surfaces the full-field stress and strain states during deformation can be utilized for many purposes such as formability limits determination, quantification of stress intensification factors, material characterization and so on. Concerning the last topic, an interesting application could be a direct identification of the elasto-plastic material response up to large deformation. It is well known, in fact, that with traditional measurement devices it is possible to retrieve the true equivalent stress versus true equivalent strain data from tensile tests only up to the onset of necking, where localization starts to occur. This work aims to show how from the knowledge of a tensile test full-field strain and of load data it will be possible to obtain the full-stress field as well as the complete material elasto-plastic behavior.

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