Prediction of Inelastic High Temperature Materials Behavior by Strain-Rate Approach

1974 ◽  
Vol 96 (2) ◽  
pp. 104-108 ◽  
Author(s):  
A. Berkovits
Keyword(s):  
Experimental Study ◽  
High Temperature ◽  
Stress Relaxation ◽  
Strain Rate ◽  
Material Flow ◽  
Flow Behavior ◽  
Creep Stress ◽  
High Temperature Materials ◽  
Materials Behavior ◽  
Unique Relationship

An experimental study of the influence of strain rate on the inelastic properties of well-aged Udimet 700 at 925 C shows a unique relationship between strain rate, strain and stress for this material. This relationship, which is presented graphically as strain rate as a function of strain, is used to compute material flow behavior under loading histories including stress-strain, creep, stress relaxation, and creep under varying stress. Results obtained compare well with predicted behavior.

Study on High Temperature Flow Stress Model of As-cast SA508-3 Low Alloy Steel

2020 ◽  
Vol 831 ◽  
pp. 25-31
Author(s):  
Pan Fei Fan ◽  
Jian Sheng Liu ◽  
Hong Ping An ◽  
Li Li Liu
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Strain Rate ◽  
Alloy Steel ◽  
Flow Behavior ◽  
Peak Stress ◽  
Stress Model ◽  
Low Alloy Steel ◽  
Two Stage ◽  
Flow Stress Model

In order to obtain the high temperature flow behavior of as-cast SA508-3 low alloy steel, the stress-strain curves of steel are obtained by Gleeble thermal simulation compression test at deformation temperature 800°C-1200°C and strain rate 0.001s-1-1s-1. Based on Laasraoui two-stage flow stress model, a high temperature flow stress model is established by multiple linear regression method. The results show that the peak stress characteristics are not obvious at low temperature and high strain rate, which is a typical dynamic recovery characteristic. Meanwhile, the peak stress characteristics are obvious at high temperature and low strain rate, which is a typical dynamic recrystallization characteristic. By means of the comparisons between experiments and calculations, the Laasraoui two-stage flow stress model can truly reflect flow behavior of steel at high temperature, which provides theoretical guidance for the hot deformation of the steel.

scholarly journals High-Temperature Deformation Behaviors of the C-Doped and N-Doped High Entropy Alloys

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1517
Author(s):  
Hailong Yi ◽  
Yifan Zhang ◽  
Renyi Xie ◽  
Mengyuan Bi ◽  
Daixiu Wei
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Flow Behavior ◽  
Temperature Deformation ◽  
Cubic Phase ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Recrystallization Mechanism ◽  
Low Strain Rate

High entropy alloys (HEAs) containing multi-principal metallic constituents have attracted much attention. A good understanding of their hot-deformation behavior and recrystallization mechanism is the prerequisite for microstructures tuning and for optimizing mechanical performance. Here, the flow behavior and recrystallization mechanism of the N-doped and C-doped face-centered cubic phase HEAs are produced at high temperatures by hot-compression at 1123–1273 K, with strain rates of 0.1–0.001 s−1. Constitutive equations were successfully constructed to reveal flow behavior, and stress-strain curves were predicted using strain compensated polynomial functions. Discontinuous and continuous dynamic recrystallization proceeded concurrently when compressed at a low temperature and high strain rate, whereas discontinuous recrystallization, which occurs at primary grain boundaries, became predominant at a high temperature and low strain rate, significantly contributing to the refinement and homogenization of the grains. For this reason, a relatively high temperature and a low strain rate, in which the recrystallized grains exhibit equiaxed morphology and very weak texture, are more suitable for refining grains. The average size of the grains was approximately 10 μm. This study sheds light on grain optimization and mechanical properties through thermomechanical processing.

scholarly journals Constitutive Analysis on High-Temperature Flow Behavior of 3Cr-1Si-1Ni Ultra-High Strength Steel for Modeling of Flow Stress

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 42 ◽  
Author(s):  
Bingwang Lei ◽  
Gaoqiang Chen ◽  
Kehong Liu ◽  
Xin Wang ◽  
Xiaomei Jiang ◽  
...  
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Strain Rate ◽  
Constitutive Equations ◽  
High Strength Steel ◽  
Flow Behavior ◽  
High Strength ◽  
Strain Dependence ◽  
Constitutive Analysis ◽  
Ultra High Strength Steel

High-temperature plastic flow is the underlying process that governs the product quality in many advanced metal manufacturing technologies, such as extrusion, rolling, and welding. Data and models on the high-temperature flow behavior are generally desired in the design of these manufacturing processes. In this paper, quantitative constitutive analysis is carried out on 3Cr-1Si-1Ni ultra-high strength steel, which sheds light on the mathematic relation between the flow stress and the thermal-mechanical state variables, such as temperature, plastic strain, and strain rate. Particularly, the hyperbolic-sine equation in combination with the Zener-Hollomon parameter is shown to be successful in representing the effect of temperature and strain rate on the flow stress of the 3Cr-1Si-1Ni steel. It is found that the flow stress of the 3Cr-1Si-1Ni steel is significantly influenced by strain. The strain-dependence on flow stress is not identical at different temperatures and strain rates. In the constitutive model, the influence of strain in the constitutive analysis is successfully implemented by introducing strain-dependent constants for the constitutive equations. Fifth-order polynomial equations are employed to fit the strain-dependence of the constitutive constant. The proposed constitutive equations which considers the compensation of strain is found to accurately predict flow stress of the 3Cr-1Si-1Ni steel at the temperatures ranging from 800 °C to 1250 °C, strain rate ranging from 0.01/s to 10/s, and strain ranging from 0.05 to 0.6.

Experimental study and prediction of deformation behavior of low carbon steel at low strain rate and high temperature

2013 ◽  
Vol 58 (10) ◽  
pp. 940-945 ◽  
Author(s):  
Wei ZHOW ◽  
GuiNan ZHANG ◽  
Ying XIA ◽  
TongBin SHAO ◽  
Xue Fei CHEN ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Temperature ◽  
Carbon Steel ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Low Strain Rate

Prediction Methodology of Creep Performance from Stress Relaxation Measurements

2013 ◽  
Vol 401-403 ◽  
pp. 920-923 ◽  
Author(s):  
Jin Quan Guo ◽  
Hui Chao Shi ◽  
Wu Zhou Meng
Keyword(s):  
High Temperature ◽  
Stress Relaxation ◽  
Creep Strain ◽  
Estimation Method ◽  
Creep Tests ◽  
High Temperature Materials ◽  
Relaxation Measurements ◽  
Isothermal Creep ◽  
The Relationship ◽  
Good Agreement

An estimation method to predict creep performances of high temperature structural materials has been proposed. The method is to use a simplified and normalized model of stress relaxation to derive creep strain rates and creep strain vs. time curves from stress relaxation measurements through an integrated analytical procedure according to the relationship between stress relaxation and creep. In order to validate the approach, the predicted results are compared to the experimental results of uni-axial isothermal creep tests conducted on 1Cr10NiMoW2VNbN steel with the same temperature of stress relaxation tests. Good agreement between results of relaxation tests and the predicted results indicates that the developed method can be recommended in the creep behavior evaluation of high temperature materials.

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