Constitutive equations for elevated temperature flow stress of Ti–6Al–4V alloy considering the effect of strain

The mechanical properties of nickel beryllide, NiBe, have been investigated in the temperature range 20–820 °C. The room temperature properties were studied using tension, bending, and compression tests, while the elevated temperature properties were characterized in compression only. NiBe exhibits some ductility at room temperature; the strains to failure in tension and compression are 1.3% and 13%, respectively. Fracture is controlled primarily by the cohesive strength of grain boundaries. At high temperatures, NiBe is readily deformable—strains in excess of 30% can be achieved at temperatures as low as 400 °C. Strain hardening rates are high, and the flow stress decreases monotonically with temperature. The high temperature strength of NiBe is as good or better than that of NiAl, but not quite as good as CoAl.

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Prediction of High Temperature Flow Stress for AISI 4120 Steel during Hot Compression

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.233.339 ◽

2012 ◽

Vol 233 ◽

pp. 339-342 ◽

Cited By ~ 1

Author(s):

Ming Ping Zou ◽

Wu Jiao Xu ◽

Peng Cheng Wang

Keyword(s):

High Temperature ◽

Flow Stress ◽

Constitutive Equation ◽

Constitutive Equations ◽

Good Prediction ◽

Compression Tests ◽

Absolute Relative Error ◽

Constitutive Analysis ◽

Average Absolute Relative Error ◽

Deformation Behaviors

To investigate the hot deformation behaviors of AISI 4120 steel, isothermal compression tests were conducted using Gleeble-1500 thermal-mechanical simulator in the temperature range of 1073-1373K with the strain rate of 0.01-10s-1. The hyperbolic sine law in Arrhenius type is used in the constitutive modeling for AISI 4120. The influence of strain is incorporated in constitutive analysis by considering the effect of strain on material constants α, n, Q and ln A. The flow stress values predicted by the developed constitutive equations show a good agreement with experimental results, which reveals that the developed constitutive equations could give an accurate and precise prediction for the high temperature flow behaviors of AISI 4120 steel. The predictability of developed constitutive equation was further quantified in terms of correlation coefficient (R) and average absolute relative error (AARE). The R and AARE were found to be 0.9847 and 8.0372% respectively, which reflects the good prediction capabilities of the developed constitutive equation.

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Prediction of the Flow Stress of 00Cr17Ni14Mo2 Steel during Hot Deformation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.460-461.802 ◽

2011 ◽

Vol 460-461 ◽

pp. 802-805

Author(s):

Nan Hai Hao ◽

Shao Wei Pan

Keyword(s):

Stainless Steel ◽

Elevated Temperature ◽

Flow Stress ◽

Hot Deformation ◽

Flow Behavior ◽

Strain Rates ◽

Forming Process ◽

Proposed Model ◽

316L Austenitic Stainless Steel ◽

Deformation Tests

The knowledge of the flow behavior of metals during hot deformation is of great importance in determining the optimum forming conditions. In this paper, the flow stress of 00Cr17Ni14Mo2 (ANSI 316L) austenitic stainless steel in elevated temperature is measured with compression deformation tests. The temperatures at which the steel is compressed are 800-1100°C with strain rates of 0.01-1s-1. A mathematical regression model is proposed to describe the flow stress and the validation of the model is conducted also. The proposed model can be used to predict the corresponding flow stress-strain response of 00Cr17Ni14Mo2 stainless steel in elevated temperature for the numerical simulation and design of forming process.

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