Effect of Divorced Eutectoid Transformation Temperature on Behaviour of Cementite Growth in GCr15 Steel

2011 ◽  
Vol 194-196 ◽  
pp. 296-300 ◽  
Author(s):  
Hong Bo Yang ◽  
Fu Xian Zhu ◽  
Xiang Hua Liu ◽  
Kuai She Wang
Keyword(s):  
Lower Limit ◽  
Transformation Temperature ◽  
Bearing Steel ◽  
Eutectoid Transformation ◽  
Eutectoid Temperature ◽  
Gcr15 Steel ◽  
Upper Limit ◽  
Gcr15 Bearing Steel ◽  
Different Temperatures

Cementite spheroidization of GCr15 bearing steel includes granulating and growth of cementite. The effects of divorced eutectoid transformation (DET) temperatures on growth of cementite were studied. It was found that the particles of cementite are fine and uniform when DET occurs at 690～720°С, and alloy elements mostly precipitate at different temperatures during cementite growth of GCr15 bearing steel; Cr and Si mostly precipitate in the eutectoid temperature upper limit, while Mn is in the eutectoid temperature lower limit.

scholarly journals Three-Dimensional Cellular Automata Simulation of the Austenitizing Process in GCr15 Bearing Steel

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3022
Author(s):  
Fuyong Su ◽  
Wenli Liu ◽  
Zhi Wen
Keyword(s):  
Cellular Automaton ◽  
Grain Growth ◽  
Three Dimensional ◽  
Bearing Steel ◽  
Cellular Automaton Model ◽  
Gcr15 Steel ◽  
Processing Times ◽  
Gcr15 Bearing Steel ◽  
Different Temperatures ◽  
Simulation Results

On the basis of the two-dimensional cellular automaton model, a three-dimensional cellular automaton model of austenitizing process was established. By considering the orientation of pearlite layer and the direction of austenite grain growth, the velocity of the interface was calculated during the austenitizing process. The austenitizing process of GCr15 steel was simulated, and the anisotropy of grain growth rate during austenitization was demonstrated by simulation results. By comparing the simulation results with the experimental data, it was found that the calculated results of the three-dimensional cellular automaton model established in this paper were in good agreement with the experimental results. By using this model, the three-dimensional austenitizing process of GCr15 steel at different temperatures and under different processing times can be analyzed, and the degree of austenitization can be predicted.

scholarly journals Exploring the role of −NH2 functional groups of ethylenediamine in chemical mechanical polishing of GCr15 bearing steel

Friction ◽  
2020 ◽  
Author(s):  
Hanqiang Wu ◽  
Liang Jiang ◽  
Xia Zhong ◽  
Jinwei Liu ◽  
Na Qin ◽  
...  
Keyword(s):  
Functional Groups ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Bearing Steel ◽  
Mechanical Polishing ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Acidic Ph ◽  
Gcr15 Steel ◽  
Gcr15 Bearing Steel

AbstractEthylenediamine with two −NH2 functional groups was used as a critical complexing agent in chemical mechanical polishing (CMP) slurries for a high carbon chromium GCr15 bearing steel (equivalent to AISI 52100). The polishing performance and corresponding mechanism of −NH2 functional groups were thoroughly investigated as a function of pH. It is revealed that, when polished with ethylenediamine and H2O2-based slurries, the material removal rate (MRR) and surface roughness Ra of GCr15 steel gradually decrease as pH increases. Compared with acidic pH of 4.0, at alkaline pH of 10.0, the surface film of GCr15 steel has much higher corrosion resistance and wear resistance, and thus the material removal caused by the pure corrosion and corrosion-enhanced wear are greatly inhibited, resulting in much lower MRR and Ra. Moreover, it is confirmed that a more protective composite film, consisting of more Fe3+ hydroxides/oxyhydroxides and complex compounds with −NH2 functional groups of ethylenediamine, can be formed at pH of 10.0. Additionally, the polishing performance of pure iron and a medium carbon 45 steel exhibits a similar trend as GCr15 steel. The findings suggest that acidic pH could be feasible for amine groups-based complexing agents to achieve efficient CMP of iron-based metals.

Modeling and Simulation of Dynamic Recrystallization of GCr15 Steel Using Cellular Automaton Method

2013 ◽  
Vol 750 ◽  
pp. 156-159 ◽  
Author(s):  
Xiao Hu Deng ◽  
Zhou De Qu ◽  
Li Wen Zhang ◽  
Dong Ying Ju
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Cellular Automaton ◽  
Volume Fraction ◽  
Accurate Determination ◽  
Structural Evolution ◽  
Bearing Steel ◽  
Gcr15 Steel ◽  
Gcr15 Bearing Steel ◽  
Ca Model

A modified two-dimensional (2-D) cellular automaton (CA) model was constructed to simulate dynamic recrystallization (DRX) process of GCr15 steel. Particle stimulated nucleation (PSN) was incorporated into the CA model to determine the influence of dispersed particles on the nucleation of DRX. In addition, the model included the effects of particles on increasing the dislocation density and pinning the grain boundaries for accurate determination of micro-structural evolution during DRX. The model was applied to simulate the DRX process of GCr15 bearing steel. DRX grain size and volume fraction were simulated using the CA model. The simulated results indicated that the simulated stable grain size of particle-containing model is closer to measured value than particle-free model. It was observed that DRX kinetics depends on both thermo-mechanical parameters and initial grain sizes. The calculated results were compared with the experimental findings in GCr15 bearing steel, the predictions show very good agreement with the experimental results.

Effect of Ultrasonic Treatment on the Solidification Microstructure of GCr15 Bearing Steel

2016 ◽  
Vol 35 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Jianjun Wang ◽  
Xiaofang Shi ◽  
Lizhong Chang ◽  
Haijun Wang ◽  
Lipeng Meng
Keyword(s):  
Liquid Steel ◽  
Ultrasonic Treatment ◽  
Side Wall ◽  
Bearing Steel ◽  
Ultrasonic Power ◽  
Gcr15 Steel ◽  
Gcr15 Bearing Steel ◽  
Columnar Grains ◽  
Equiaxed Grains ◽  
Suitable Power

AbstractUltrasonic treatment with various powers is introduced to liquid steel from the side wall of a mold during GCr15 steel solidification, and the effect of ultrasonic on the microstructure and properties of GCr15 steel is investigated. Results show that the columnar grains in the GCr15 steel are coarse and that the microstructure is inhomogeneous when ultrasonic is not applied on the liquid steel. A suitable power ultrasonic leads to the appearance of a large number of equiaxed grains and increases the uniformity of the microstructure. The segregation of alloy elements gradually decreases as the power increases from 0 W to 500 W. The maximum segregations of carbon and silicon decrease from 2.541 to 1.129 and 2.861 to 1.196, respectively. Given a power of 500 W, the statistical segregations of carbon and silicon decrease from 0.0964 to 0.0693 and 0.1152 to 0.1075, respectively. A further increase in ultrasonic power is not conducive for improving the element segregation. Ultrasonic treatment can remarkably refine the size of carbide and increase the uniformity of its distribution. When the powers are 0 W, 300 W, 500 W, 700 W, and 1,000 W, the average sizes of carbide are 14.63 μm, 2.96 μm, 3.05 μm, 3.72 μm, and 7.83 μm, respectively. The tensile strength, yield strength, and ductility and reduction of the area of the GCr15 bearing steel are correspondingly improved to varying degrees.

PNN and BP Neural Network Fault Diagnosis Research on Electronic Accelerator Pedal Detection

2020 ◽  
Vol 14 (2) ◽  
pp. 205-220
Author(s):  
Yuxiu Jiang ◽  
Xiaohuan Zhao
Keyword(s):  
Neural Network ◽  
Fault Diagnosis ◽  
Fault Detection ◽  
Lower Limit ◽  
Bp Neural Network ◽  
Accelerator Pedal ◽  
Electronic Throttle ◽  
Measured Voltage ◽  
Upper Limit ◽  
Network Fault

Background: The working state of electronic accelerator pedal directly affects the safety of vehicles and drivers. Effective fault detection and judgment for the working state of the accelerator pedal can prevent accidents. Methods: Aiming at different working conditions of electronic accelerator pedal, this paper used PNN and BP diagnosis model to detect the state of electronic accelerator pedal according to the principle and characteristics of PNN and BP neural network. The fault diagnosis test experiment of electronic accelerator pedal was carried out to get the data acquisition. Results: After the patents for electronic accelerator pedals are queried and used, the first measured voltage, the upper limit of first voltage, the first voltage lower limit, the second measured voltage, the upper limit of second voltage and the second voltage lower limit are tested to build up the data samples. Then the PNN and BP fault diagnosis models of electronic accelerator pedal are established. Six fault samples are defined through the design of electronic accelerator pedal fault classifier and the fault diagnosis processes are executed to test. Conclusion: The fault diagnosis results were analyzed and the comparisons between the PNN and the BP research results show that BP neural network is an effective method for fault detection of electronic throttle pedal, which is obviously superior to PNN neural network based on the experiment data.

TiN/ZrO2 multilayers synthesized on GCr15 bearing steel using plasma immersion ion implantation and deposition

2007 ◽  
Vol 201 (15) ◽  
pp. 6615-6618 ◽  
Author(s):  
Tao Sun ◽  
Langping Wang ◽  
Yonghao Yu ◽  
Yuhang Wang ◽  
Xiaofeng Wang ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Bearing Steel ◽  
Gcr15 Bearing Steel ◽  
Plasma Immersion Ion Implantation

The Excavation of Eighteen Round Barrows near Shrewton, Wiltshire.

1984 ◽  
Vol 50 ◽  
pp. 255-318 ◽  
Author(s):  
Charles Green ◽  
Stephen Rollo-Smith ◽  
Elisabeth Crowfoot ◽  
Calvin Wells
Keyword(s):  
Water Supply ◽  
Lower Limit ◽  
Open Water ◽  
Linear Groups ◽  
Upper Limit ◽  
The Village

The excavation of eighteen round barrows was undertaken by the late Charles Green during summer seasons from 1958 to 1960, in advance of their destruction by ploughing. The excavated barrows are members of two linear groups which occupy adjacent spurs to the east of the village of Shrewton in the modern parish of that name (fig. 1). One of the barrows investigated lies in Winterbourne Stoke parish. This western part of Salisbury Plain is termed the ‘Lower Plain’ comprising those areas having their ‘upper limit… between 400 and 450 feet OD and their lower limit where they overlook the valley trenches … between 250 and 300 feet O.D.’ (Gifford 1957, 6). In such a lower valley lie the modern villages of Shrewton and Rollestone, and through it flows the river Till, the nearest modern open water supply to the barrows. This connects the area to the River Avon via the Wylye and Nadder.

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