Effects of temperature and strain rate on flow behavior and microstructural evolution of super duplex stainless steel under hot deformation

2016 ◽  
Vol 23 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Ming Ma ◽  
Hua Ding ◽  
Zheng-you Tang ◽  
Jing-wei Zhao ◽  
Zhou-hua Jiang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Duplex Stainless Steel ◽  
Microstructural Evolution ◽  
Hot Deformation ◽  
Flow Behavior ◽  
Super Duplex Stainless Steel ◽  
Effects Of Temperature

Flow Behavior and Microstructural Evolution of an As-Wrought Duplex Stainless Steel during Hot Compression Deformation

2013 ◽  
Vol 699 ◽  
pp. 808-812
Author(s):  
Lei Chen ◽  
Xiao Cong Ma ◽  
Ming Jia Wang ◽  
Hua Gui Huang
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Duplex Stainless Steel ◽  
Microstructural Evolution ◽  
Flow Behavior ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Lower Strain ◽  
Dynamic Softening ◽  
Gleeble 3500

The flow behavior and microstructural evolution of an as-wrought duplex stainless steel has been investigated by Gleeble-3500 thermal-mechanical simulator within the temperature range of 950-1200°C and the strain rate range of 0.1-10s-1. The flow curves exhibited a peak stress characteristic followed by dynamic softening and the strain for appearance of steady stress is bigger at higher strain rate than at lower strain rate. The apparent activation energy (Q) and the apparent stress exponent (n) of the test steel are obtained to be about 462 kj/mol and 3.95, respectively. The relationship between peak stress (σp) and Zener-Holomon parameter (Z) is obtained, whereby the σp can be predicted at differern hot working conditons. The results of microstructural observation show that the austenite softens by the dynamic recrystallization (DRX) which can be dominantly responsib le for dynamic softening, while the ferrite phase mainly continues to exhibit dynamic recovery (DRV).

Processing Map and Microstructural Evolution of Isothermal Compressed an Al-Mg-Si-Cu-Zn Alloy

2016 ◽  
Vol 877 ◽  
pp. 575-580
Author(s):  
Li Zhen Yan ◽  
Yong An Zhang ◽  
Bai Qing Xiong ◽  
Zhi Hui Li ◽  
Xi Wu Li ◽  
...  
Keyword(s):  
Strain Rate ◽  
Microstructural Evolution ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Processing Map ◽  
Flow Behavior ◽  
Processing Condition ◽  
Electron Back Scatter Diffraction ◽  
Microstructure Observation ◽  
Hot Rolled

The hot deformation behavior of an Al-0.92Mg-0.78Si-0.20Cu-0.60Zn alloy was studied by isothermal compression in the temperature range from 350 to 500 oC with strain rates of 0.01-10s-1 on Gleeble-1500 thermo-mechanical simulator. The microstructural evolution during hot deformation was investigated by electron back-scatter diffraction (EBSD). The results show that the strain rate and deformation temperature have significant influence on flow behavior, and the flow stress increases with increasing strain rate and decreasing deformation temperature. Processing map at the strain of 0.7 is obtained and exhibits three peak efficiency domains (380-420 oC at 0.01s-1, 480-500 oC at 0.01s-1 and 450-500 oC at 0.1-0.32s-1). According to the processing map and microstructure observation, the optimized processing condition of hot deformation for the alloy is at 450-500 oC and strain rate of 0.1-0.32s-1. The homogenized ingot is hot rolled at 480 oC with a strain rate of 0.1s-1 based on optimized deformation parameters. The fraction of high-angle grain boundary is 35.2%, which is in accord with microstructure after hot deformed at 500 oC with a strain rate of 0.1s-1.

Capability of a Feed-Forward Artificial Neural Network to Predict the Constitutive Flow Behavior of As Cast 304 Stainless Steel Under Hot Deformation

2006 ◽  
Vol 129 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Sumantra Mandal ◽  
P. V. Sivaprasad ◽  
S. Venugopal
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Stainless Steel ◽  
Strain Rate ◽  
Hot Deformation ◽  
Flow Behavior ◽  
304 Stainless Steel ◽  
Compression Tests ◽  
Feed Forward ◽  
Artificial Neural

A model is developed to predict the constitutive flow behavior of as cast 304 stainless steel during hot deformation using artificial neural network (ANN). The inputs of the neural network are strain, strain rate, and temperature, whereas flow stress is the output. Experimental data obtained from hot compression tests in the temperature range 1023-1523K, strain range 0.1-0.5, and strain rate range 10−3-102s−1 are employed to develop the model. A three-layer feed-forward ANN is trained with standard back propagation and some upgraded algorithms like resilient propagation (Rprop) and superSAB. The performances of these algorithms are evaluated using a wide variety of standard statistical indices. The results of this study show that Rprop algorithm performs better as compared to others and thereby considered as the most efficient algorithm for the present study. It has been shown that the developed ANN model can efficiently and accurately predict the hot deformation behavior of as cast 304 stainless steel. Finally, an attempt has been made to quantify the extrapolation ability of the developed network.

Investigation on Hot Deformation Behavior of 430 Ferritic Stainless Steel

2013 ◽  
Vol 721 ◽  
pp. 82-85
Author(s):  
Jian Bin Zhang ◽  
Dong Mei Yu ◽  
Shao Rui Niu ◽  
Gen Shun Ji
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Ferritic Stainless Steel ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Flow Behavior ◽  
Peak Stress ◽  
Hot Deformation Behavior ◽  
Hollomon Parameter ◽  
Deformation Equation

The hot deformation behavior and microstructure evolution of 430 ferritic stainless steel (430 FSS) were investigated within the temperature range of 950°C~1150°C at the strain rate of 0.01 s-1, 0.1 s-1, and 1.0 s-1using a thermo-mechanical simulator. The effects of temperature and strain rate on the flow behavior and microstructures of 430 ferritic stainless steel at reduction ratio 50 % were analyzed. Results indicated that the apparent stress exponent and the apparent activation energy of the steel were about 1.08 and 344 kJ/mol, respectively. The hot deformation equation of 430 was considered as. There was a relationship between the softening mechanism and Zener-Hollomon parameter (abbreviated Z). With the Z value increasing from 4.30×1010to 5.00×1014, the hot deformation peak stress correspondingly increased from 10.74 MPa to 76.02MPa.

scholarly journals Effects of Temperature and Strain Rate on Tensile Properties of a Lean Duplex Stainless Steel

2014 ◽  
Vol 54 (8) ◽  
pp. 1971-1977 ◽  
Author(s):  
Noriyuki Tsuchida ◽  
Taiji Kawahata ◽  
Eiichiro Ishimaru ◽  
Akihiko Takahashi
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Duplex Stainless Steel ◽  
Tensile Properties ◽  
Lean Duplex Stainless Steel ◽  
Effects Of Temperature

Flow Behavior and Microstructural Evolution of a 7039 Aluminum Alloy during Hot Deformation

2011 ◽  
Vol 239-242 ◽  
pp. 2395-2398 ◽  
Author(s):  
Hui Zhong Li ◽  
Xiao Peng Liang ◽  
Min Song ◽  
Min Zeng
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Microstructural Evolution ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Flow Behavior ◽  
Thermal Simulation ◽  
Strain Rates

The flow behavior of a 7039 aluminum alloy and the corresponding microstructural evolution during hot deformation were studied by Gleeble-1500 thermal simulation tests, EBSD and TEM observations with temperatures ranging from 300 °C to 500 °C under strain rates from 0.01 s-1 to 10 s-1. It has been shown that the flow stress increases with the decrease in the deformation temperature and increase in the strain rate. The degree of dynamic recrystallization (DRX) increases with the increase in the deformation temperature and strain rate in 7039 aluminum alloy. The complete dynamic recrystallization occurs at 500 °C with a strain rate of 10 s-1.

scholarly journals Microstructure Evolution during Hot Deformation of UNS S32750 Super-Duplex Stainless Steel Alloy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3916
Author(s):  
Elisabeta Mirela Cojocaru ◽  
Anna Nocivin ◽  
Doina Răducanu ◽  
Mariana Lucia Angelescu ◽  
Ion Cinca ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Hot Deformation ◽  
Physical And Mechanical Properties ◽  
Processing Parameters ◽  
Experimental Program ◽  
Recrystallization Process ◽  
Total Degree ◽  
Super Duplex Stainless Steel ◽  
Degree Of Deformation

The present paper analyzes UNS S32750 Super-Duplex Stainless Steel hot deformation behavior during processing by upsetting. The objective of this paper is to determine the optimum range of deformation temperatures, considering that both austenite and ferrite have different deformation behaviors due to their different morphology, physical, and mechanical properties. Because the capability of plastic deformation accommodation of ferrite is reduced when compared to austenite, side cracks and fissures can form during the hot deformation process. Consequently, it is important to find the optimum conditions of deformation of this type of stainless steel to establish the best processing parameters without deteriorating the material. The experimental program involved the application of hot deformation by the upsetting method on a series of samples between 1000 °C and 1275 °C, with a total degree of deformation of 30%. The resultant samples were examined by SEM-EBSD to establish and analyze the evolution of the phases present in the structure from several points of view: nature, distribution, morphology (size and shape), and their structural homogeneity. The GROD (Grain Reference Orientation Deviation) distribution map was also determined while taking into account the possible precipitation of the secondary austenite phase (γ2-phase) and the analysis of the dynamic recrystallization process according to the applied deformation temperature. The main conclusion was that UNS S32750 SDSS steel can be safely deformed by upsetting between 1050–1275 °C, with an experimented total degree of deformation of 30%.

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