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International Journal of Minerals,Metallurgy and Materials 2022年第4期29卷 836-847页

作者： Bogdan Nenchev Qing Tao Zihui Dong Chinnapat Panwisawas Haiyang Li Biao Tao Hongbiao Dong NISCO UK Research Centre School of EngineeringUniversity of LeicesterLeicester LE17RHUK Nanjing Iron&Steel United Co. Ltd.Nanjing 210044China

Data-driven algorithms for predicting mechanical properties with small datasets are evaluated in a case study on gear steel *** limitations of current data-driven algorithms and empirical models are *** in analysing small datasets are discussed,and solution is proposed to handle small datasets with multiple *** methods in combination with novel predictive algorithms are utilized to overcome the challenges in analysing gear steel hardenability data and to gain insight into alloying elements interaction and structure *** gained fundamental knowledge integrated with machine learning is shown to be superior to the empirical equations in predicting ***-property relationships between chemistry,sample size,and hardness are predicted via two optimized machine learning algorithms:neural networks(NNs)and extreme gradient boosting(XGboost).A comparison is drawn between all algorithms,evaluating their performance based on small data *** results reveal that XGboost has the highest potential for predicting hardenability using small datasets with class imbalance and large inhomogeneity issues.

关键词： machine learning small dataset XGboost hardenability gear steel

Effect of controlled rolling on the martensitic hardenability of dual phase steel

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International Journal of Minerals,Metallurgy and Materials 2009年第2期16卷 165-169页

作者： Mohammad Ajmal Masood Ahmed Tindyala Ron Priestner Department of Metallurgical & Materials Engineering University of Engineering & TechnologyG.T. Road Lahore-54890Pakistan Manchester Materials Science Center University of Manchester Institute of Science and Technology (UMIST)ManchesterM1 7HSUK

The C-Mn and C-Mn-Nb steels were thermo-mechanically processed to develop dual phase steel and to study the effect of controlled rolling on the martensitic hardenability of austenite. The steel specimens were intercritically annealed at 790℃, rolled at that temperature to the reductions of 10%, 23%, and 47% and immediately cooled at different rates. Quantitative metallography was used to construct the microstructure map, which illustrated that increasing deformation progressively reduced the proportion of new ferrite formed at all cooling rates and increased the amount of martensite at fast and intermediate rates. The martensitic hardenability of austenite remaining after all the rolling reductions was plotted as a function of cooling rates. It was observed that for the austenite-martensite conversion efficiencies greater than about 25%, controlled rolling increased the martensitic hardenability of austenite.

关键词： controlled rolling dual phase steel intercritical annealing hardenability phase transformation

Determination and Analysis of hardenability for Hot-Forging Die Steels with Deep-Hardening

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Journal of Iron and Steel Research International 2000年第1期7卷 27-30页

作者： ZHAO Gang JIANG Min QIN Gao-wu HAO Shi-ming GU Rong DAI Jian-ming Northeastern University Research Institute of Fushun Steel Plant

ERH end-quenching method was used to determine the hardenability of four kinds hot-forging die steels with deep-hardening and hence the order of their hardenability was *** tempering hardness of the steels was measured and the tempering resistance was *** was approved that ERH method is effective for the determination of hardenability of deep-hardening steel and the beginning of hardness drop in the ERH specimen is caused by bainite occurring.

关键词： hardenability deep-hardening steel hot-forging die steel tempering resistance

Application of Artificial Neural Network to Predicting hardenability of Gear Steel

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Journal of Iron and Steel Research International 2006年第6期13卷 71-73页

作者： GAO Xiu-hua QI Ke-min DENG Tian-yong QIU Chun-lin ZHOU Ping DU Xian-bin State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China Technical Center Laiwu Iron and Steel Co Ltd Laiwu 271104 Shandong China

The prediction of the hardenability and chemical composition of gear steel was studied using artificial neural networks. A software was used to quantitatively forecast the hardenability by its chemical composition or the chemical composition by its hardenability. The prediction result is more precise than that obtained from the traditional method based on the simple mathematical regression model.

关键词： artificial neural network (ANN) gear steel hardenability 20CrMnTiH

Effect of Mn on hardenability of 25CrMo axle steel by an improved end-quench test

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China Foundry 2012年第4期9卷 318-321页

作者： Zhang Yutuo Bian Shu Han Weixin Shenyang Ligong University Shenyang 110159China Institute of Metal Research CAS Shenyang 110016China

With the sixth large-scale railway speed-up,the quality of the axles is essential to the safety of the *** to the high-speed axle technical standard for the control of alloy elements in axle steel,optimization experiments of 25CrMo steel composition were performed by vacuum inductive *** order to study the hardenability of high-speed rail axles,an improved end-quench test was put *** advantage is that it enables the heat to transfer along the axial direction,thus avoiding edge *** hardenability of 25CrMo axle steels with Mn content of 0.60wt.% and 0.80wt.% was investigated mainly by means of optical microscopy and hardness *** experimental results indicate that the Mn has a pronounced effect on the hardenability of the *** an increase in Mn content from 0.60wt.% and 0.80wt.%,the hardenability of 25CrMo axle steel increases and the hard microstructure is maintained at an increasing distance from the quenched *** the surface of the water quenched end to the center of the sample,the microstructure is martensite,martensite with bainite,and bainite.

关键词： 25CrMo steel end-quench test hardenability microstructure Mn content

Fabrication of End Quenched Machine: hardenability Evaluation

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Journal of Minerals and Materials Characterization and Engineering 2014年第2期2卷 107-113页

作者： A. A. Yekinni J. O. Agunsoye S. A. Bello I. O. Awe S. I. Talabi Department of Mechanical Engineering Lagos State Polytechnic Lagos Nigeria Department of Metallurgical and Materials Engineering University of Ilorin Ilorin Nigeria Department of Metallurgical and Materials Engineering University of Lagos Lagos Nigeria Department of Metallurgical Engineering Yaba College of Technology Lagos Nigeria

The Jominy end quench machine was designed, manufactured and tested. The manganese steel was developed. The as-cast manganese steels were quenched in water at different austenising temperatures and hardenability test was carried out on the samples cut at different distances from the quenched surface with the use of the manufactured Jominy end quench machine. The optical microscope was used to investigate the microstructure of the cut samples. Results revealed that the Jominy end quench machine worked effectively with short cycle time and improved water management system. The extremely rapid cooling prevents the decomposition of the chromium carbides. However, the hardness values of the samples decreased with increase in the distance from the quenched surface and the size of the chromium carbides increased with austentic temperatures which is responsible for reduction in the hardness values of the quenched samples at higher austentinic temperature. The manufactured Jominy end quench machine has advantages of improved water management system and short processing time over the existing ones.

关键词： hardenability Jominy Specimen Martensitic Mass Effect Microstructure

Modified Tartagli method for calculation of Jominy hardenability curve

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Modified Tartagli method for calculation of Jominy hardenabi...

Heat Treatment Properties of 42CrMo Steel for Bearing Ring of Varisized Shield Tunneling Machine

第五届国际材料与热加工物理模拟及数值模拟学术会议

作者： Wojciech Sitek Jacek Trzaska Leszek A. Dobrzański Institute of Engineering Materials and Biomaterials Faculty of Mechanical Engineering Silesian University of Technology Konarskiego St.18A 44-100 Gliwice POLAND Institute of Engineering Materials and Biomaterials Faculty of Mechanical Engineering Silesian University of Technology Konarskiego St.18A 44-100 Gliwice POLAND Institute of Engineering Materials and Biomaterials Faculty of Mechanical Engineering Silesian University of Technology Konarskiego St.18A 44-100 Gliwice POLAND

Basing on the experimental results of the hardenability investigations, which employed Jominy method, the model of the neural networks was developed and fully verified experimentally. The model makes it possible to obtain Jominy hardenability curves basing on the steel chemical composition. The modified hardenability curves calculation method is presented in the paper, initially developed by Tartaglia, Eldis, and Geissler, later extended by T. Inoue. The method makes use of the similarity of the Jominy curve to the hyperbolic secant function. The empirical formulae proposed by the authors make calculation of the hardenability curve possible basing on the chemical composition of the steel. However, regression coefficients characteristic for the particular steel grade must be known. Replacing some formulae by the neural network models is proposed in the paper.

关键词： hardenability Jominy curve modeling neural networks.

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 383-388页

作者： Bo Jiang Leyu Zhou Xinli Wen Chaolei Zhang Yazheng Liu School of Materials Science and Engineering University of Science and Technology Beijing

The heat treatment properties of 42CrMo steel for bearing ring of varisized shield tunneling machine were investigated by optical microscope （OM）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, and impact tests. The addition of 0.03 wt% C into 42CrMo steel can increase the hardness. But it reduces the impact energy by 46 J because of the appearance of coarser carbides in the matrix and the carbides along the austenite grain boundary. The addition of 0.40 wt% Mn into 42CrMo steel can improve hardenability. However, the toughness of steel is also reduced by 26 J mainly because of the coarsening of carbides and the strengthening of matrix. Both hardenability and toughness of 42CrMo steel can be improved by adding 1.49 wt% Ni and reducing 0.32 wt% Cr. The depth of hardening layer can be raised to 45 mm, and the impact energy at -20 ℃ is 120 J. Thus, it is concluded that a good combination of hardness, hardenability, and toughness of 42CrMo steel can be achieved by alloying with adding some content of C and Ni. Detailed content of C and Ni should be on the requirements of heat treatment properties of steel for bearing ring of varisized shield tunneling machine.

关键词： Shield tunneling machine Bearing ring 42CrMo steel hardenability Toughness

Development of a New Kind of High Strength Spring Steel

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Journal of Materials Science & Technology 2004年第5期20卷 557-560页

作者： DexiangXU ZhongdaYIN DefuLIU LiabilityCompany BeimanSpecialSteelGroupQiqihar161041China HarbinInstituteofTechnology Harbin150001China

A new kind of high strength, high toughness and high plasticity spring steel has been developed. The strength, the reduction of area and the elongation of the steel are all higher than those of the steel 60Si2CrVA. The decarburization resistance and the sag resistance are also higher than those of the steel 60Si2CrVA. It has good hardenability, and is suitable for making springs with big cross section. The bogie springs made of this kind of steel have passed 2×106 cycles without broken under the conditions of maximum stress of 906 MPa and the minimum stress of 388 MPa.

关键词： Spring steel High strength Toughness Plasticity Sag resistance hardenability Fatigue

Microstructure and mechanical properties of ultralow carbon high-strength steel weld metals with or without Cu-Nb addition

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International Journal of Minerals,Metallurgy and Materials 2021年第1期28卷 120-130页

作者： Xing-hai Yang Xiao-hua Chen Shi-wei Pan Zi-dong Wang Kai-xuan Chen Da-yong Li Jun-wei Qin School of Material Science and Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

Two types of ultralow carbon steel weld metals(with and without added Cu-Nb) were prepared using gas metal arc welding(GMAW) to investigate the correlation between the microstructure and mechanical properties of weld *** results of microstructure characterization showed that the weld metal without Cu-Nb was mainly composed of acicular ferrite(AF), lath bainite(LB), and granular bainite(GB).In contrast, adding Cu-Nb to the weld metal caused an evident transformation of martensite and grain *** weld metals had a high tensile strength(more than 950 MPa) and more than 17% elongation;however, their values of toughness deviated greatly,with a difference of approximately 40 J at-50℃.Analysis of the morphologies of the fracture surfaces and secondary cracks further revealed the correlation between the microstructure and mechanical *** effects of adding Cu and Nb on the microstructure and mechanical properties of the weld metal are discussed;the indication is that adding Cu-Nb increases the hardenability and grain size of the weld metal and thus deteriorates the toughness.

关键词： weld metal microstructure mechanical properties hardenability grain coarsening