Flow stress of Nitronic-50 stainless steel over a wide range of strain rates and temperatures

2006 ◽  
Vol 38 (11) ◽  
pp. 1090-1103 ◽  
Author(s):  
Wei-Guo Guo ◽  
Sia Nemat-Nasser
Keyword(s):  
Stainless Steel ◽  
Flow Stress ◽  
Strain Rates ◽  
Wide Range

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

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.

scholarly journals Random Forest Approach in Modeling the Flow Stress of 304 Stainless Steel during Deformation at 700 °C–900 °C

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1812
Author(s):  
Shin-Hyung Song
Keyword(s):  
Stainless Steel ◽  
Flow Stress ◽  
Random Forest ◽  
Industrial Applications ◽  
304 Stainless Steel ◽  
Strain Rates ◽  
Random Forest Algorithm ◽  
Stress Behavior ◽  
Corrosive Environments ◽  
Stress Variations

The alloy 304 stainless steel is used in a wide variety of industrial applications. It is frequently applied in tough environments, such as those involving high temperatures, low temperatures, and corrosive environments. Hence, research on the flow stress behavior of the alloy during deformation under tough environments is critically important to achieving the maximum effectiveness in the application of the alloy. This research presents a study on the flow stress of 304 stainless steel during hot deformation at the temperatures of 700 °C–900 °C under the strain rates ranging from 0.0002/s–0.02/s. For this study, hot tensile experiments are conducted, and the flow stress variations of the alloy are studied with respect to the variations in the strain rate and temperature. Next, the stress behavior was modeled by the traditional Arrhenius-type constitutive equation and random forest algorithm. Then, the flow stresses predicted by different methods were studied by comparing errors. The results showed that the flow stress was modeled more accurately by the random forest algorithm.

Constitutive flow stress formulation for aeronautic aluminum alloy AA7075-T6 at elevated temperature and model validation using finite element simulation

2016 ◽  
Vol 230 (6) ◽  
pp. 994-1004
Author(s):  
Uma Maheshwera Reddy Paturi ◽  
Suresh Kumar Reddy Narala
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Flow Stress ◽  
Elevated Temperatures ◽  
Constitutive Models ◽  
Absolute Error ◽  
Machining Process ◽  
Strain Rates ◽  
Average Absolute Error ◽  
Wide Range

A judicious material constitutive model used as input to the numerical codes to denote elastic, plastic, and thermomechanical behavior under elevated temperatures and strain rates is essential to analyze and design a process. This work describes the formulation of different constitutive models, such as Johnson–Cook, Zerilli–Armstrong, Arrhenius, and Norton–Hoff models for high-strength aeronautic aluminum alloy AA7075-T6 under a wide range of deformation temperatures and strain rates. The adeptness of the formulated models is evaluated statistically by comparing the value of the correlation coefficient and average absolute error between experimental and predicted flow stress results, and numerically when simulating AA7075-T6 machining process. Though all the models show a reasonable degree of accuracy of fit, based on the average absolute error of the data and finite element predictions when simulating the AA7075-T6 machining process, Zerilli–Armstrong model can offer an accurate and precise estimate and is very close to the experimental results over the other models.

Identification of Aluminum Alloy Flow Stress to Determine FEM Analysis Constitutive Equation for Machining Material

2016 ◽  
Vol 874 ◽  
pp. 457-462
Author(s):  
Takashi Nakamura ◽  
Hiroyuki Sasahara ◽  
Shota Kusunose ◽  
Itaru Nishizaki
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Cutting Forces ◽  
Railway Vehicle ◽  
Correct Identification ◽  
Strain Rates ◽  
Engineering Structures ◽  
Friction Stir ◽  
Wide Range

To predict accurate cutting forces and residual stresses while machining products or to design optimum machining conditions like friction stir welding (FSW), FEM analyses are effective because they can reduce the cost of product design and improve product qualities. In order to conduct these FEM analyses precisely, it is necessary to determine accurate flow stresses of workpieces used for the constitutive equations of analyses that generally have a wide range of temperatures and strain rates. Correct identification of flow stress can lead to better analysis results close to actual phenomenon. In this study, focusing on 6061-T6 aluminum alloy used for objects such as civil engineering structures and railway vehicle bodies, we investigated the properties for machining the material. For this, we carried out an inverse analysis to understand the flow stress of 6061-T6 machined at high-strain rates and high temperatures. Then, we used this identified flow stress in the constitutive equation of FEM models, and inspected the accuracy of material properties conducting verification experiments and analyses to check the cutting forces and chip temperature while machining. As a result, we obtained good correlations between verification experiments and an analysis, which means the identified flow stress can be used for precise FEM analyses when machining materials.

Comparisons of Constitutive Models for Steel Over a Wide Range of Temperatures and Strain Rates

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Farid Abed ◽  
Fadi Makarem
Keyword(s):  
Flow Stress ◽  
Strain Hardening ◽  
Shear Bands ◽  
Constitutive Models ◽  
Steel Structures ◽  
High Strength ◽  
Stress And Strain ◽  
Strain Rates ◽  
Wide Range ◽  
Strain Hardening Behavior

This study investigates and compares several available plasticity models used to describe the thermomechanical behavior of structural steel subjected to complex loadings. The main purpose of this comparison is to select a proper constitutive model that can later be implemented into a finite element code to capture localizations (e.g., shear bands and necking) in steel and steel structures subjected to low- and high-velocity impact. Four well-known constitutive models for viscoplastic deformation of metals, i.e., Johnson–Cook (JC), Zerilli–Armstrong (ZA), Rusinek–Klepaczko (RK), and Voyiadjis–Abed (VA), have been investigated and compared with reference to existing deformation data of HSLA-65 and DH-36 steel conducted at low and high strain rates and various initial temperatures. The JC, ZA, and RK models reasonably describe the flow stress and the strain hardening behavior only in the certain ranges of strain, strain rate, and temperature for which the models were developed. This was attributed to the inaccurate assumptions used in developing these models. In contrast, the VA model most effectively describes the flow stress and strain hardening in which very good predictions are observed for the constitutive behavior of high strength steel over a wide range of strains, strain rates, and temperatures.

scholarly journals Effects of Temperature and Strain Rate on the Fracture Behaviors of an Al-Zn-Mg-Cu Alloy

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1233 ◽  
Author(s):  
Yue Guo ◽  
Mingxing Zhou ◽  
Xingdong Sun ◽  
Long Qian ◽  
Lijia Li ◽  
...  
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Peak Stress ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Cu Alloy ◽  
Deformation State ◽  
Wide Range ◽  
Fracture Behaviors ◽  
Effects Of Temperature

Effects of temperature and strain rate on the fracture behaviors of an Al-Zn-Mg-Cu alloy are investigated by isothermal uniaxial tensile experiments at a wide range of temperatures and strain rates, from room temperature (RT) to 400 °C and from 10−4 s−1 to 10−1 s–1, respectively. Generally, the elevation of temperature leads to the increasing of elongation to fracture and the reduction of peak stress, while higher strain rate results in the decreasing of elongation to fracture and the increasing of peak stress. Interestingly, we found that the coefficient of strain rate sensitivity (m-value) considerably rises at 200 °C and work of fracture (Wf) fluctuates drastically with the increase of strain rate at RT and 100 °C, both of which signify a non-uniform and unstable deformation state below 200 °C. A competition of work hardening (WH) and dynamic recrystallization (DRX) exists at 200 °C, making it serve as a transitional temperature. Below 200 °C, WH is the main deformation mechanism of flow stress, and DRX dominates the flow stress above 200 °C. It has been found that from RT to 200 °C, the main feature of microstructure is the generation of dimples and microvoids. Above 200 °C, the coalescence of dimples and microvoids mainly leads to the failure of specimen, while the phenomenon of typically equiaxed dimples and nucleation appear at 400 °C. The observations of microstructure are perfectly consistent with the related macroscopic results. The present work is able to provide a comprehensive understanding of flow stress of an Al-Zn-Mg-Cu alloy at a wide range of temperatures and strain rates, which will offer valuable information to the optimization of the hot forming process and structural design of the studied alloy.

Hot Deformation of Martensitic and Supermartensitic Stainless Steels

2016 ◽  
Vol 870 ◽  
pp. 259-264 ◽  
Author(s):  
A.M. Akhmed'yanov ◽  
S.V. Rushchits ◽  
M.A. Smirnov
Keyword(s):  
Stainless Steel ◽  
Flow Stress ◽  
Stainless Steels ◽  
Hot Deformation ◽  
Strain Rates ◽  
Peak Strain ◽  
Hollomon Parameter ◽  
Deformation Activation Energy ◽  
The Difference ◽  
Strain Increase

The deformation behavior of supermartensitic and martensitic stainless steels was investigated through compression test using Gleeble-3800 thermo-mechanical simulator within the temperature range of 900 – 1200 оС and the strain rates range of 0.01 – 10 s-1. The results showed that the flow stress and the peak strain increase with the drop in the deformation temperature and the rise in the strain rate. Flow stress of SMS steel exceeds flow stress of MS steel for same regimes of deformation. The difference in flow stress increases with the increase in Zener-Hollomon parameter, but does not exceed 15 MPa. The critical deformation, required to start dynamic recrystallization, for supermartensitic stainless steel is slightly lower than for martensitic stainless steel. The hot deformation activation energy of steels is also investigated, their values are similar and equal to 432 and 440 kJ/mol for MS and SMS steel, respectively.

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