Microstructure evolution and dynamic recrystallization mechanism during thermal deformation of GH4698 superalloy

Copper fragments are found to adhere on penetration channel wall after copper jets penetrate steel target, and the research on it is helpful to know microstructure evolution of jets in the process of penetration and cooling time. This paper is based on the observation of bore in steel target penetrated by copper jets, and uses numerical simulation to study the process of copper jets penetration, then the change of temperature and grain size of jets adhered on penetration channel wall can be gotten, and the results agree with the observation of penetration channel wall taken by SEM. From the observations of copper and steel, we can get the conclusion that copper jets are not melted but have dynamic recrystallization in the process of penetration, then copper grain size increases obviously in cooling time, and twins are formed at the same time.

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Hot Deformation Behavior Considering Strain Effects and Recrystallization Mechanism of an Al-Zn-Mg-Cu Alloy

Materials ◽

10.3390/ma13071743 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1743 ◽

Cited By ~ 3

Author(s):

Lei Luo ◽

Zhiyi Liu ◽

Song Bai ◽

Juangang Zhao ◽

Diping Zeng ◽

...

Keyword(s):

Dynamic Recrystallization ◽

Hot Deformation ◽

Deformation Behavior ◽

Processing Parameters ◽

Strain Rate Range ◽

Hot Compression ◽

Processing Maps ◽

Hot Deformation Behavior ◽

Recrystallization Mechanism ◽

Cu Alloy

The hot deformation behavior of an Al-Zn-Mg-Cu alloy was investigated by hot compression test at deformation temperatures varying from 320 to 440 °C with strain rates ranging from 0.01 to 10 s−1. The results show that the Mg(Zn, Cu)2 particles as a result of the sufficient static precipitation prior to hot compression have an influence on flow softening. A constitutive model compensated with strain was developed from the experimental results, and it proved to be accurate for predicting the hot deformation behavior. Processing maps at various strains were established. The microstructural evolution demonstrates that the dominant dynamic softening mechanism stems from dynamic recovery (DRV) and partial dynamic recrystallization (DRX). The recrystallization mechanism is continuous dynamic recrystallization (CDRX). The microstructure observations are in good agreement with the results of processing maps. On account of the processing map and microstructural observation, the optimal hot processing parameters at a strain of 0.6 are at deformation temperature range of 390–440 °C and strain rate range of 0.010–0.316 s−1 with a peak efficiency of 0.390.

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Effect of Dynamic Recrystallization on Microstructure Evolution and Texture Weakening During Annealing of High Speed Rolled AZ31 Magnesium Alloy Sheets

Magnesium Technology 2016 ◽

10.1007/978-3-319-48114-2_53 ◽

2016 ◽

pp. 267-271

Author(s):

Jing Su ◽

Abu Syed H. Kabir ◽

Mehdi Sanjari ◽

In-Ho Jung ◽

Stephen Yue

Keyword(s):

Magnesium Alloy ◽

Dynamic Recrystallization ◽

Microstructure Evolution ◽

High Speed ◽

Az31 Magnesium Alloy

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An Investigation into the Dynamic Recrystallization (DRX) Behavior and Processing Map of 33Cr23Ni8Mn3N Based on an Artificial Neural Network (ANN)

Materials ◽

10.3390/ma13061282 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1282 ◽

Cited By ~ 2

Author(s):

Zhongman Cai ◽

Hongchao Ji ◽

Weichi Pei ◽

Xuefeng Tang ◽

Long Xin ◽

...

Keyword(s):

Neural Network ◽

Experimental Data ◽

Artificial Neural Network ◽

Dynamic Recrystallization ◽

Microstructure Evolution ◽

Processing Map ◽

Resistant Steel ◽

Ann Model ◽

Heat Resistant Steel ◽

Artificial Neural Network Ann

Based on an 33Cr23Ni8Mn3N thermal simulation experiment, the application of an artificial neural network (ANN) in thermomechanical processing was studied. Based on the experimental data, a microstructure evolution model and constitutive equation of 33Cr23Ni8Mn3N heat-resistant steel were established. Stress, dynamic recrystallization (DRX) fraction, and DRX grain size were predicted. These models were evaluated by a variety of statistical indicators to determine that these models would work well if applied in predicting microstructure evolution and that they have high precision. Then, based on the weight of the ANN model, the sensitivity of the input parameters was analyzed to achieve an optimized ANN model. Based on the most widely used sensitivity analysis (SA) method (the Garson method), the input parameters were analyzed. The results show that the most important factor for the microstructure of 33Cr23Ni8Mn3N is the strain rate ( ε ˙ ). For the control of the microstructure, the control of the ε ˙ is preferred. ANN was applied to the development of processing map. The feasibility of the ANN processing map on austenitic heat-resistant steel was verified by experiments. The results show that the ANN processing map is basically consistent with processing map based on experimental data. The trained ANN model was implanted into finite element simulation software and tested. The test results show that the ANN model can accurately expand the data volume to achieve high precision simulation results.

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Effects of Continuous Extrusion on Microstructure Evolution and Property Characteristics of Brass Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.2921 ◽

2011 ◽

Vol 189-193 ◽

pp. 2921-2924 ◽

Cited By ~ 2

Author(s):

Bing Li ◽

Chun Hai Li ◽

Xiang Jun Yao ◽

Bao Yun Song

Keyword(s):

Dynamic Recrystallization ◽

Microstructure Evolution ◽

Mechanical Treatment ◽

Extrusion Process ◽

Brass Alloy ◽

Microstructure And Properties ◽

Continuous Extrusion ◽

Extruded Products ◽

The Right

The continuous extrusion process would refine the microstructure effectively and increase the formability and properties of extrusion products, without preheating and post-mechanical treatment. During the continuous extrusion operation the microstructure of brass alloy significantly influences formability and properties. So the microstructure evolution rules of brass alloy during the whole continuous extrusion process were analyzed, and the hardness changing laws of the extruded brass alloy were also researched in this paper. By observing the microstructure evolution at different regions, the evolution rules of microstructure and properties of the continuous extrusion brass alloy were obtained. It was found that the dynamic recrystallization occurred at the right-angle bending region, which was proved by the hardness evolution of the extruded brass alloy. Therefore, it is feasible to control the properties of the extruded products by concentrating the right-angle bending region. This work gives the researching foundation of low formability materials based on continuous extrusion operation.

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