Unified Tensile Work Hardening Behaviour of Thin Section Plate and Forged Thick Section 9Cr-1Mo Ferritic Steel

2013 ◽  
Vol 32 (3) ◽  
pp. 287-294
Author(s):  
B.K. Choudhary ◽  
E. Isaac Samuel ◽  
D.P. Rao Palaparti ◽  
J. Christopher ◽  
M.D. Mathew
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Work Hardening ◽  
Ferritic Steel ◽  
True Stress ◽  
Rate Of Change ◽  
Plastic Strain Rate ◽  
True Plastic Strain ◽  
Temperature Regimes ◽  
Material Conditions

AbstractDetailed investigation has been performed on tensile work hardening behaviour in terms of the variations of instantaneous work hardening rate (θ = dσ/dεp, where σ is true stress and εp is true plastic strain) with stress and true plastic strain rate (ε̇p) for temperature range 300–873 K in two different material conditions, (i) normalised and tempered plate and (ii) quenched and tempered tubeplate forging of 9Cr-1Mo ferritic steel. Both plate and tubeplate forging exhibited two-stage work hardening and three different temperature regimes in the variation of θ with σ. The variations of θ with respect to ε̇p exhibited unified work hardening in terms of a single master curve independent of temperature and initial microstructure. θ varied linearly with reciprocal of plastic strain rate, i.e. 1/ε̇p, and as a consequence, linear correlation between the rate of change of true stress and true plastic strain rate independent of temperature and microstructure has been obtained.

Tensile Testing at Constant True Plastic Strain Rate

JOM ◽  
1980 ◽  
Vol 32 (7) ◽  
pp. 23-28 ◽  
Author(s):  
Craig S. Hartley ◽  
David A. Jenkins
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Tensile Testing ◽  
Plastic Strain Rate ◽  
True Plastic Strain

Slow plastic strain rate compressive flow in binary CoAl intermetallics

1985 ◽  
Vol 73 ◽  
pp. 87-96 ◽  
Author(s):  
J. Daniel Whittenberger
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Plastic Strain Rate ◽  
Compressive Flow

An Experimental Study on the Effect of Prior Plastic Straining on Creep Behavior of 304 Stainless Steel

1993 ◽  
Vol 115 (2) ◽  
pp. 200-203 ◽  
Author(s):  
Z. Xia ◽  
F. Ellyin
Keyword(s):  
Stainless Steel ◽  
Plastic Strain ◽  
Strain Rate ◽  
Creep Behavior ◽  
Test Procedure ◽  
Constant Strain Rate ◽  
304 Stainless Steel ◽  
Creep Model ◽  
Plastic Strain Rate ◽  
Creep Tests

Constant strain-rate plastic straining followed by creep tests were conducted to investigate the effect of prior plastic straining on the subsequent creep behavior of 304 stainless steel at room temperature. The effects of plastic strain and plastic strain-rate were delineated by a specially designed test procedure, and it is found that both factors have a strong influence on the subsequent creep deformation. A creep model combining the two factors is then developed. The predictions of the model are in good agreement with the test results.

An Assessment of the Method Used to Determine Activation Parameters in L12 Alloys

1998 ◽  
Vol 552 ◽  
Author(s):  
B. Matterstock ◽  
G. Saada ◽  
J. Bonneville ◽  
J. L Martin
Keyword(s):  
Mechanical Properties ◽  
Theoretical Analysis ◽  
Plastic Strain ◽  
Strain Rate ◽  
Characteristic Time ◽  
Constant Strain Rate ◽  
Activation Parameters ◽  
Plastic Strain Rate ◽  
Clear Indication ◽  
Load Relaxation

ABSTRACTThe characterisation of dislocation mechanisms in connection with macroscopic mechanical properties are usually performed through transient tests, such as strain-rate jumps, load relaxations or creep experiments. The present paper includes a careful and complete theoretical analysis of the relaxation and the creep kinetics. We experimentally show that the plastic strain-rate is continuous at the transition between constant strain-rate conditions and both load relaxation and creep test. The product of the plastic strain-rate at the onset of the transient test () with the characteristic time (tk) of the transient is found to be independent of , as theoretically expected. This is a clear indication that the assumptions underlying the theoretical analysis are relevant.

Calculation of Material Flow in Orthogonal Cutting by Using Streamline Model

2009 ◽  
Vol 407-408 ◽  
pp. 490-493 ◽  
Author(s):  
Xue Feng Bi ◽  
Gautier List ◽  
Yong Xian Liu
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Line Shape ◽  
Material Flow ◽  
General Equation ◽  
Flow Line ◽  
Orthogonal Cutting ◽  
Plastic Strain Rate ◽  
Complex Variation ◽  
Streamline Method

The streamline method was used to investigate the plastic strain rate in machining. The streamline function presented in this paper is a general equation with three parameters controlling the complex variation of flow line shape. Velocity and deformation field were obtained by streamline analysis. The validation of this model was conducted by comparing with other experimental results published. It shows that the streamline model presented in the paper can be applied to the evaluation of strain rate in machining.

scholarly journals How to Realize Volume Conservation During Finite Plastic Deformation

2017 ◽  
Vol 84 (11) ◽  
Author(s):  
Heling Wang ◽  
Dong-Jie Jiang ◽  
Li-Yuan Zhang ◽  
Bin Liu
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Strain Rate ◽  
Plastic Strain Rate ◽  
Strain Rate Tensor ◽  
Cauchy Stress ◽  
Volume Conservation ◽  
Tangential Stiffness ◽  
Manufacture Process ◽  
Universal Approach

Volume conservation during plastic deformation is the most important feature and should be realized in elastoplastic theories. However, it is found in this paper that an elastoplastic theory is not volume conserved if it improperly sets an arbitrary plastic strain rate tensor to be deviatoric. We discuss how to rigorously realize volume conservation in finite strain regime, especially when the unloading stress free configuration is not adopted in the elastoplastic theories. An accurate condition of volume conservation is first clarified and used in this paper that the density of a volume element after the applied loads are completely removed should be identical to that of the initial stress free states. For the elastoplastic theories that adopt the unloading stress free configuration (i.e., the intermediate configuration), the accurate condition of volume conservation is satisfied only if specific definitions of the plastic strain rate are used among many other different definitions. For the elastoplastic theories that do not adopt the unloading stress free configuration, it is even more difficult to realize volume conservation as the information of the stress free configuration lacks. To find a universal approach of realizing volume conservation for elastoplastic theories whether or not adopt the unloading stress free configuration, we propose a single assumption that the density of material only depends on the trace of the Cauchy stress by using their objectivities. Two strategies are further discussed to satisfy the accurate condition of volume conservation: directly and slightly revising the tangential stiffness tensor or using a properly chosen stress/strain measure and elastic compliance tensor. They are implemented into existing elastoplastic theories, and the volume conservation is demonstrated by both theoretical proof and numerical examples. The potential application of the proposed theories is a better simulation of manufacture process such as metal forming.

Cyclic creep and the effect of vibrations on the plastic strain rate in materials

1987 ◽  
Vol 19 (3) ◽  
pp. 325-329
Author(s):  
T. S. Voznyi
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Cyclic Creep ◽  
Plastic Strain Rate

Transient functions for plastic strain rate changes

1976 ◽  
Vol 38 (2) ◽  
pp. 539-546 ◽  
Author(s):  
B. Wielke ◽  
G. Schoeck
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Plastic Strain Rate
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