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Micromechanical Behavior and Failure Mechanism of F / B Multi-phase High Performance Steel

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Journal of Iron and Steel Research International 2016年第5期23卷 489-494页

作者： Cun-jiang TANG Shi-long LIU cheng-jia shang School of Materials Science and Engineering University of Science and Technology Beijing

The deformation and micro-voids formation mechanisms in ferrite / bainite（ F / B） multi-phase steel with the volume fraction of bainite less than 50% were studied by numerical simulation and experimental observation. The results show that the micro-strain concentrates at the soft / hard phase（ F / B） interface in the multi-phase steel,which should be correlated with the mechanism of incoordinate deformation. During the necking of the steel,the micro-voids initially form around the F / B interface,which also form in ferrite and bainite with the severe strain. The micro-voids in bainite are more dense and finer than those in ferrite. The failure mechanism of bainite is the coalescence of micro-voids,and the failure mechanism of ferrite is the growth and tearing of micro-voids. Due to the different failure mechanisms of ferrite and bainite,a suitable part of soft phase would be beneficial to the capability of anti-failure of F / B multi-phase steel during the ductile fracture.

关键词： ferrite / bainite multi-phase steel numerical simulation ferrite / bainite interface micro-strain micro-void failure mechanism soft phase

Grain refinement in the coarse-grained region of the heat-affected zone in low-carbon high-strength microalloyed steels

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International Journal of Minerals,Metallurgy and Materials 2010年第6期17卷 737-741页

作者： Ran Wei cheng-jia shang Kai-ming Wu International Research Institute for Steel Technology Wuhan University of Science and Technology Wuhan 430081 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The microstructural features and grain refinement in the coarse-grained region of the heat-affected zone in low-carbon high-strength microalloyed steels were investigated using optical microscopy, scanning electron microscopy, and electron backscattering dif- fraction. The coarse-grained region of the heat-affected zone consists of predominantly bainite and a small proportion of acicular ferrite. Bainite packets are separated by high angle boundaries. Acicular ferrite laths or plates in the coarse-grained region of the heat-affected zone formed prior to bainite packets partition austenite grains into many smaller and separate areas, resulting in fine-grained mixed microstruc- tures. Electron backscattefing diffraction analysis indicates that the average crystallographic grain size of the coarse-grained region of the heat-affected zone reaches 6-9 μm, much smaller than that of anstanite grains.

关键词： microalloyed steels welding grain refinement bainite acicular ferrite

Structure and Dynamics of Energy Materials from Machine Learning Simulations:A Topical Review

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Chinese Journal of Chemistry 2021年第11期39卷 3144-3154页

作者： Shu-Hui Guan cheng shang Zhi-Pan Liu shanghai Academy of Agricultural Sciences Shanghai201403 China Collaborative Innovation Center of Chemistry for Energy Material Shanghai Key Laboratory of molecular Catalysis and Innovative MaterialsKey Laboratory of Computational Physical ScienceDepartment of ChemistryFudan UniversityShanghai200438 China

Energy materials featuring the capability to store and release chemical energy reversibly involve generally complex geometrical structures with multiple *** has been a great challenge to establish the quantitative relationship between the structure of materials and their dynamic physicochemical *** recent years,machine learning(ML)technique has demonstrated its great power in accelerating the research on energy *** topical review introduces the key ingredients and typical applications of ML to energy *** mainly focus on the ML based atomic simulation via ML potentials in different architectures/implementations,including high dimensional neural networks(HDNN),Gaussian approximation potential(GAP),moment tensor potentials(MTP)and stochastic surface walking global optimization with global neural network potential(SSW-NN)*** cases studies,namely,Si,LiC and LiTiO systems,are presented to demonstrate the ability of ML simulation in assessing the thermodynamics and kinetics of complex material *** highlight that the SSW-NN method provides an automated solution for global potential energy surface data collection,ML potential construction and ML simulation,which boosts the current ability for large-scale atomic simulation and thus holds the great promise for fast property evaluation and material discovery.

关键词： Machine learning Materials science Atomic simulation Thermodynamics Kinetics

Surface Nanocrystallization of Nb-Ti Stabilized 439M Ferritic Stainless Steel

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Journal of Iron and Steel Research International 2014年第9期21卷 891-896页

作者： Yao-chun ZHANG Chao CHEN cheng-jia shang Dong-yang LI Nuclear Equipment Division CNNC China Nuclear Power Engineering Co.Ltd. School of Materials Science and Engineering University of Science and Technology Beijing Department of Chemical and Materials Engineering University of AlbertaEdmonton T6G2V4AlbertaCanada

A new nanocrystallization process was designed, which included punching the surface coating to generate dislocation network or cells and recovery treatment to turn the dislocation cells into nano-sized grains. The effort was made to increase the service life of Nb-Ti stabilized 439M stainless steel surface with medium passive ability, particularly to enhance the outmost surface layer by nanocrystallization for improving resistances to corrosion. Electrochemical properties, electron work functions （EWFs）, nano-mechanical properties of the nanocrystallized surfaces were investigated. It was demonstrated that the nanocrystallized 439M stainless steel surface exhibited improved resistance to corrosion in 0.5 mol/L H2 SO4 solution. However, the nanoci＇ystallized 439M stainless steel surface exhibited decreased resistance to corrosion in 3.5% NaCl solution.

关键词： nanocrystallization corrosion ferritic stainless steel punching recovery

Flavonoids from the stems and leaves of Scutellaria baicalensis Georgi attenuate H_2O_2-induced oxidative damage to rat cortical neurons

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Neural Regeneration Research 2011年第27期6卷 2100-2104页

作者： Yongping Liu Kai Cao Hong Miao Jianjun cheng Yazhen shang Key Laboratory of Traditional Chinese Medicine Research and Development of Hebei Province Institute of Traditional Chinese MedicineChengde Medical College Chengde 067000 Hebei Province China

Primary cultures of rat cortical neurons were treated with H2O2 in an in vitro model of free radical neurotoxicity. Flavonoids extracted from the stems and leaves of Scutellaria baicalensis Georgi, known as SSF, at concentrations of 18.98, 37.36 and 75.92 μg/mL, protected neurons against H2O2 injury in a dose-dependent manner. SSF increased cell survival, reduced lactate dehydrogenase release and inhibited malondialdehyde production. SSF also inhibited reductions in superoxide dismutase, glutathione peroxidase and Na＋-K＋-ATPase activities. These results in-dicate that SSF can protect rat cortical neurons against H2O2-induced oxidative injury.

关键词： flavonoids from Scutellaria baicalensis Georgi H2O2 lactate dehydrogenase superoxide dismutase malondialdehyde glutathione peroxidase Na+-K+-ATPase neural regeneration

Nucleation Analysis of Variant Transformed from Austenite with Σ_(3) Boundary in High-Strength Low-Alloy Steel

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Acta Metallurgica Sinica(English Letters) 2021年第4期34卷 523-533页

作者： Bin-Bin Wu Zhi-Quan Wang cheng-Jia shang Yi-Shuang Yu Devesh Misra Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China State Key Laboratory of Metal Material for Marine Equipment and Application Anshan114000China Laboratory for Excellence in Advanced Steel Research Department of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas at El Paso500 WUniversity AvenueEl PasoTX79968USA

We elucidate here the effects of annealing twins on phase transformation products based on electron back-scatter diffraction analysis and corresponding microstructure visualization and quantification *** and bainite were obtained by rapid continuous cooling and isothermal processing at different temperatures,respectively,which were designed to study variants formed in austenite with Σ_(3) *** isothermal transformation near martensite start(M_(s))temperature was most conducive in obtaining the highest content of twin-related V_(1)/V_(2) variant *** on the classical nucleation theory of martensite and bainite,respectively,the role of austenite Σ_(3) boundary in martensite and bainite transformation is illustrated.

关键词： Steel AusteniteΣ_(3)boundary Variant Phase transformation Martensite Bainite

Molybdenum alloying in high-performance flat-rolled steel grades

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Advances in Manufacturing 2020年第1期8卷 15-34页

作者： Pello Uranga cheng-Jia shang Takehide Senuma Jer-Ren Yang Ai-Min Guo Hardy Mohrbacher CEIT and TECNUN University of NavarraSan SebastianSpain Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083People's Republic of China Graduate School for Nature Science Okayama UniversityOkayamaJapan Institute of Materials Science and Engineering Taiwan UniversityTaipeiTaiwanPeople's Republic of China CITIC Metal Beijing 100027People's Republic of China Department of Materials Engineering KU LeuvenLeuven 3001Belgium NiobelCon bvba Schilde 2970Belgium

Considerable progress in developing flat-rolled steel grades has been made by the Chinese steel industry over the recent two *** increasing demand for high-performance products to be used in infrastructural projects as well as in production of consumer and capital goods has been driving this development until *** installation of state-of-the-art steel making and rolling facilities has provided the possibility of processing the most advanced steel *** production of high-performance steel grades relies on specific alloying elements of which molybdenum is one of the most *** is nearly self-sufficient in molybdenum *** paper highlights the potential and advantages of molybdenum alloying over the entire range of flat-rolled steel *** aspects of steel property improvement with respect to particular applications are indicated.

关键词： HSLA steel Quench&tempering Direct quenching Press hardening Quenching&partitioning Precipitation

Properties and homogeneity of 550-MPa grade TMCP steel for ship hull

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International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 179-184页

作者： Yi Nie cheng-jia shang Xin Song Yang You Chuang Li Xin-lai He School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Department of Physics and Chemistry Henan Polytechnic University Jiaozuo 454000 China

Ultra low carbon steels by the thermal mechanical control process（TMCP） with less Ni,Cr,and Mo contents have been developed for 550 MPa grade heavy gauge ship hulls and offshore *** relationships among microstructures,process,and properties of the studied steel have been investigated.A series of accurate control technologies have been developed for this kind of *** microalloying and TMCP＋relaxation precipitation control（RPC）＋accelerated cooling process were employed to optimize the mechanical properties and ensure the homogeneity of the 80-mm thick *** microstructures of thin plates slightly changed from surface to center,but the micro-structures of the heavy gauge plate（80 mm） changed *** the simple composition,it can meet the requirement of thin plates by adopting a few *** for thick plates（80 mm）,a little higher Cu and Ni contents should be *** steels can meet the needs without *** these ways,the properties of the steels can be optimized,and the cost can be decreased notably.

关键词： microalloyed steel thick plate microstructure mechanical properties microalloying relaxation precipitation accelerated cooling

Life Prediction of Newly Developed Ferritic Stainless Steels for Automotive Muffler

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Journal of Iron and Steel Research International 2014年第1期21卷 125-130页

作者： Chao CHEN Yue ZHENG Yue ZHANG Xiao-hui LU cheng-jia shang Nuclear Equipment Division CNNC China Nuclear Power Engineering Co.Ltd. School of Materials Science and Engineering University of Science and Technology Beijing Nuclear and Radiation Safety Center MEP

Corrosion mechanism of automotive mufflers was investigated by SEM （scanning electron microscope） and XRD （X-ray diffractomer） analysis. 409L and newly developed 439M steels were evaluated in terms of condensate corrosion tests for 5 periods, 10 periods and 20 periods separately. The relative lifetimes of 409L and 439M steels were predicted according to the extreme value analysis method and pitting corrosion models. Modelling studies dem- onstrated that the predicted relative lifetime of 439M ferrite stainless steel is 6.8 times that of 409L steels. The extreme value analysis method was also successfully used in the road test. The estimated maximum corrosion depth of the 439M muffler is 0. 55 ram.

关键词： stainless steel SEMi XRD modelling study pitting corrosion