High-Range Plasticity of Metals Beyond Normal Work-Hardening

1959 ◽  
Vol 81 (2) ◽  
pp. 178-181 ◽  
Author(s):  
E. V. Crane ◽  
W. S. Wagner
Keyword(s):  
Work Hardening ◽  
Wire Drawing ◽  
Tensile Failure ◽  
Cold Extrusion ◽  
Range Data ◽  
Plastic Range ◽  
Testing Technique ◽  
Technical Data ◽  
Normal Work ◽  
High Range

Metals, plastically worked for mass-production purposes are shown to have a little known and potentially valuable “high” working range, primarily compressive and substantially beyond commonplace practices and physicals. This “high range” lies beyond the point of normal tensile failure. It is distinguished by a steeper or more rapid rate of work-hardening. While some use has been made of it, to advantage, in wire-drawing, rolling, cold extrusion, and shell drawing, inadequate technical data concerning it may be attributed to unfamiliarity with the testing program. To provide pressed-metal engineering with the extended plastic-range data needed for planning operation sequences, a testing technique is outlined, which if not new, is at least unfamiliar and potentially useful until a better method is devised.

A Law of Work-Hardening

1948 ◽  
Vol 15 (3) ◽  
pp. 265-273
Author(s):  
A. M. Freudenthal ◽  
M. Reiner
Keyword(s):  
Mild Steel ◽  
Work Hardening ◽  
Wire Drawing ◽  
Total Work ◽  
Exponential Functions ◽  
Recoverable Strain ◽  
Annealed State ◽  
Logarithmic Measure ◽  
Work Of Deformation ◽  
Crystalline Metal

Abstract Based on the “blocking” theory of the strength of a poly-crystalline metal, a law of work-hardening is derived and checked experimentally on mild steel deformed by wire-drawing up to a deformation of 4.6 in the logarithmic measure. The law correlates the recoverable strain work with the total work of deformation in a series of exponential functions, the number of which corresponds to the number of sizes of crystal grains present in the annealed state.

Influence of the Preforming Material State in Common Tribological Tests

2016 ◽  
Vol 1140 ◽  
pp. 75-82
Author(s):  
Bastian Zimmermann ◽  
Marion Merklein
Keyword(s):  
Compression Test ◽  
Work Hardening ◽  
Test Sample ◽  
Wire Drawing ◽  
Cold Forging ◽  
The Real ◽  
Friction Factors ◽  
Ring Compression ◽  
Material State ◽  
Rolled Wire

Different tests to determine friction factors for cold forging processes are given in the literature. The double cup extrusion test, the ring compression test and the T-shape compression test are three of the common tests, which are compared in this investigation. From former investigations it is known that there is an influence of the work-hardening of the test sample on the friction factor, which is determined by the test. At this study, the influence of the work-hardening of the material on the three named tests is investigated by using a wire drawing process. In addition, the drawn wire from the originally thermo mechanical rolled wire is also annealed to have a second material state without any work-hardening. The used material and its numerical modelling as well as the analyzed tribological conditions of the real specimens are described. Afterwards the three test setups are explained for the numerical as well as for the real experiments. In the end, the influence of the drawing respectively the work-hardening for the three tests is presented and discussed.

Some Properties of a Mechanical Model of Plasticity

1948 ◽  
Vol 15 (3) ◽  
pp. 222-225
Author(s):  
H. F. Bohnenblust ◽  
Pol Duwez
Keyword(s):  
Plastic Deformation ◽  
Potential Energy ◽  
Work Hardening ◽  
Mechanical Model ◽  
Strain Curve ◽  
Hysteresis Curve ◽  
Plastic Range ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Mechanical Models

Abstract Various mechanical models explaining the plastic deformation of metals have been proposed. One of the present authors has shown that in some cases an analytical expression for the stress-strain curve and the hysteresis curve of a metal in the plastic range can be deduced from such a model. The present investigation is a further analysis of the model leading to the computation of the change in potential energy of the metal due to work-hardening.

Applicability of Solid Lubricant Coatings in Cold Rod Extrusion of Stainless Steels

2020 ◽  
Vol 404 ◽  
pp. 95-100
Author(s):  
Andreas Jobst ◽  
Marion Merklein
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Work Hardening ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Equivalent Plastic Strain ◽  
Grain Structure ◽  
Cold Extrusion ◽  
Operating Characteristics ◽  
Lubricant Coating

Cold extrusion is an established technology for the production of dimensionally accurate components in large series. Due to the high material and energy efficiency, a resource-saving manufacturing of high-performance parts is possible. Forming at room temperature leads to an advantageous grain structure and work hardening of the material, resulting in components with favorable operating characteristics. Nevertheless, a challenge is the generation of residual stresses during forming, which are influencing the fatigue behavior. The modification of the tribological conditions is one method for influencing the parts’ residual stress state. However, the high strength and work hardening of the materials formed at room temperature leads to high tribological loads between billet and die. These challenges are intensified by the increasing use of stainless steels due to growing demands for corrosion resistant components. The aim followed within this paper is therefore to investigate the applicability of typical lubricant coatings in the forward rod extrusion of stainless steels. For this purpose, the ferritic stainless steel X6Cr17 (DIN 1.4016) and the ferritic-austenitic stainless steel X2CrNiMoN22-5-3 (DIN 1.4462) are extruded with an equivalent plastic strain of ε̅ ≈ 1. The research is performed with a molybdenum disulfide (MoS2), a soap and a polymer-based lubricant coating. For reproducing different contact conditions, the die geometry is varied with die opening angles of 60°, 90° and 120°. The suitability of the lubricants is evaluated using the integrity of the lubricant coating after forming. From the correlations between process forces, temperatures and surface integrity, recommendations for the application of the researched lubricants are derived.

Loading and Heating of a Simple Structure with Linear Work Hardening

1963 ◽  
Vol 67 (626) ◽  
pp. 92-102 ◽  
Author(s):  
E. H. Mansfield
Keyword(s):  
Residual Stresses ◽  
Work Hardening ◽  
Heat Load ◽  
Simple Structure ◽  
Tangent Modulus ◽  
Plastic Range ◽  
Repeated Applications ◽  
Residual Stresses And Strains

Summary:An analysis is made of the stresses and strains in a loaded two-bar tie when one of the bars is subjected to heating. The material of the bars is assumed to possess linear work hardening characteristics, i.e. a constant tangent modulus in the plastic range, and these characteristics are assumed to be independent of temperature. The following cycles of loading and heating are considered: load-heat-cool-unload, load-heat-unload-cool, heat-load-unload-cool, heat-load-cool-unload, and it is shown how, and when, these cycles produce differing stresses and strains and, in particular, differing residual stresses and strains. The effect of repeated applications of these cycles, when incremental shake-down may occur, is also considered.

A Bounding Principle in the Theory of Work-Hardening Plasticity

1969 ◽  
Vol 36 (2) ◽  
pp. 228-232 ◽  
Author(s):  
J. F. Soechting ◽  
R. H. Lance
Keyword(s):  
Work Hardening ◽  
Plastic Range ◽  
Stress States

A displacement bounding principle for continua loaded into the plastic range is presented. Use is made of Drucker’s inequality and the existence of a maximum complimentary work path between any two stress states. The bounding principle is applied to several examples.

Thermal Stresses in an Elastic, Work-Hardening Sphere

1960 ◽  
Vol 27 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Chintsun Hwang
Keyword(s):  
Work Hardening ◽  
Thermal Stresses ◽  
Yield Condition ◽  
Numerical Data ◽  
Spherical Body ◽  
Thermal And Mechanical Properties ◽  
Plastic Range ◽  
Cooling Process ◽  
Von Mises ◽  
Transient Thermal

In this paper, a method is presented for obtaining the transient thermal-stress distribution and the residual stresses in a spherical body where the time-dependent temperature distribution is symmetrical with respect to the center of the sphere. The material is assumed to be elastoplastic, while in the plastic range it work-hardens isotropically. The von Mises yield condition is used. The thermal and mechanical properties of the material are assumed to be temperature independent. The problem is reduced to a single nonlinear differential equation which is solved numerically on the NCR 304 digital computer. Several sets of numerical data representing various degrees of work-hardening in the spherical bodies during a cooling process are presented.

The Work Hardening of Pearlite during Wire Drawing

1994 ◽  
Vol 157-162 ◽  
pp. 1689-1694 ◽  
Author(s):  
P. Watté ◽  
Paul van Houtte ◽  
E. Aernoudt ◽  
J. Gil Sevillano ◽  
W. Van Raemdonck ◽  
...  
Keyword(s):  
Work Hardening ◽  
Wire Drawing
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