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Study on Evaluation Method of Failure Pressure for Pipeline with Axially Adjacent Defects
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作者 SUN Ming-ming FANG Hong-yuan +2 位作者 DU Xue-ming WANG Wen-hua LI Xin 《China Ocean Engineering》 SCIE EI CSCD 2023年第4期598-612,共15页
The interaction between axially adjacent defects is more significant than that between circumferentially aligned defects.However,the existing failure pressure assessment methods cannot accurately predict the failure p... The interaction between axially adjacent defects is more significant than that between circumferentially aligned defects.However,the existing failure pressure assessment methods cannot accurately predict the failure pressure of axial adjacent defects.In the paper,the finite element model is adopted to analyze the influence of defect size,distribution mode and spacing between adjacent defects on failure pressure.A new failure pressure evaluation method is proposed by establishing the effective depth calculation model of corrosion colony with different distribution model.The burst test of X52 pipeline is carried out to verify the applicability of the method.It shows that the results of new method are consistent with the test results of pipeline with various defects and steel grades. 展开更多
关键词 steel pipeline effective depth axially adjacent defects burst test evaluation method
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Surface decarburization characteristics and relation between decarburized types and heating temperature of spring steel 60Si2MnA 被引量:9
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作者 Chao-lei Zhang Le-yu Zhou Ya-zheng Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第8期720-724,共5页
The characteristics of complete and partial decarburizations in spring steel 60Si2MnA were systematically investigated, including the microstructure, the hardness gradient, and the formation mechanism. The relation be... The characteristics of complete and partial decarburizations in spring steel 60Si2MnA were systematically investigated, including the microstructure, the hardness gradient, and the formation mechanism. The relation between decarburized types and heating temperature of the steel was comprehensively discussed. It is found that heating temper- ature has an important influence on the decarburized types. With the rise of heating temperature, the decarburized types change from no decarburization to complete decarburization, complete and partial decarburizations, partial decarburiza- tion, and no decarburization. 展开更多
关键词 spring steel decarburization temperature MICROSTRUCTURE HARDNESS
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Forming condition and control strategy of ferrite decarburization in 60Si2MnA spring steel wires for automotive suspensions 被引量:13
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作者 Chao-lei Zhang Ya-zheng Liu +2 位作者 Le-yu Zhou Chao Jiang Jin-fu Xiao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第2期116-121,共6页
The ferrite decarburization behavior of 60Si2MnA spring steel wires for automotive suspensions, including the forming condition and the influence of heating time and cooling rate after hot rolling, was investigated co... The ferrite decarburization behavior of 60Si2MnA spring steel wires for automotive suspensions, including the forming condition and the influence of heating time and cooling rate after hot rolling, was investigated comprehensively. Also, a control strategy during the reheating process and cooling process after rolling was put forward to protect against ferrite decarburization. The results show that ferrite decarburization, which has the strong temperature dependence due to phase transformation, is produced between 675 and 875°C. The maximum depth is found at 750°C. Heating time and cooling rate after rolling have an important influence on decarburization. Reasonable preheating temperature in the billet reheating process and austenitizing temperature in the heat-treatment process are suggested to protect against ferrite decarburization. 展开更多
关键词 spring steel decarburization phase transformations controlled cooling
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Decarburization rate of RH refining for ultra low carbon steel 被引量:6
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作者 Bai-song Liu Guo-sen Zhu +3 位作者 Huan-xi Li Ben-hai Li Yang cui Ai-min Cui 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第1期22-27,共6页
The decarburization behaviors of ultra low carbon steel in a 210-t RH vacuum degasser were investigated under practical operat- ing conditions. According to the apparent decarburization rate constant (Kc) calculated... The decarburization behaviors of ultra low carbon steel in a 210-t RH vacuum degasser were investigated under practical operat- ing conditions. According to the apparent decarburization rate constant (Kc) calculated by the carbon content in the samples taken from the hot melt in a ladle at an interval of 1-2 min, it is observed that the total decarburization reaction period in RH can be divided into the quick decarburization period and the stagnant decarburization period, which is quite different from the traditional one with three stages. In this study, the average apparent decarburization rate constant during the quick decarburization period is 0.306 min^-1, and that of the stagnant period is 0.072 min^-1. Increasing the initial carbon content and enhancing the exhausting capacity can increase the apparent decarburization rate constant in the quick decarburization period. The decarburization reaction comes into the stagnant decarburization period when the carbon content in molten steel is less than 14× 10^-6 after 10 min of decarburization. 展开更多
关键词 REFINING decarburization ultra low carbon steel DEGASSING
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Physical and Mathematical Modeling of the Argon-Oxygen Decarburization Refining Process of Stainless Steel 被引量:5
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作者 魏季和 《Journal of Shanghai University(English Edition)》 CAS 2002年第1期1-23,共23页
The available studies in the literature on physical and mathematical modeling of the argon oxygen decarburization (AOD) process of stainless steel have briefly been reviewed. The latest advances made by the author wi... The available studies in the literature on physical and mathematical modeling of the argon oxygen decarburization (AOD) process of stainless steel have briefly been reviewed. The latest advances made by the author with his research group have been summarized. Water modeling was used to investigate the fluid flow and mixing characteristics in the bath of an 18 t AOD vessel, as well as the 'back attack' action of gas jets and its effects on the erosion and wear of the refractory lining, with sufficiently full kinematic similarity. The non rotating and rotating gas jets blown through two annular tuyeres, respectively of straight tube and spiral flat tube type, were employed in the experiments. The geometric similarity ratio between the model and its prototype (including the straight tube type tuyeres) was 1:3. The influences of the gas flow rate, the angle included between the two tuyeres and other operating parameters, and the suitability of the spiral tuyere as a practical application, were examined. These latest studies have clearly and successfully brought to light the fluid flow and mixing characteristics in the bath and the overall features of the back attack phenomena of gas jets during the blowing, and have offered a better understanding of the refining process. Besides, mathematical modeling for the refining process of stainless steel was carried out and a new mathematical model of the process was proposed and developed. The model performs the rate calculations of the refining and the mass and heat balances of the system. Also, the effects of the operating factors, including adding the slag materials, crop ends, and scrap, and alloy agents; the non isothermal conditions; the changes in the amounts of metal and slag during the refining; and other factors were all considered. The model was used to deal with and analyze the austenitic stainless steel making (including ultra low carbon steel) and was tested on data of 32 heats obtained in producing 304 grade steel in an 18 t AOD vessel. The changes in the bath composition and temperature during the refining process with time can be accurately predicted using this model. The model can provide some very useful information and a reliable basis for optimizing the process practice of the refining of stainless steel and control of the process in real time and online. 展开更多
关键词 stainless steel argon oxygen decarburization (AOD) process fluid flow and mixing back attack phenomenon non rotating and rotating gas jets decarburization water modeling mathematical modeling.
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Mathematical Model of Decarburization of Ultra Low Carbon Steel during RH Treatment 被引量:1
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作者 ZHANG Lifeng JING Xuejing +2 位作者 LI Jiying XU Thongbo CAI Kaike(Metallurgy Engineering School, USTB, Beijing 100083, China) 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 1997年第4期19-23,共5页
According to the balance of carbon and oxygen, a decarburization model for the RH treatment has been developed. in which the influence of the mass transfer of carbon and oxygen in the liquid steel and the stirring ene... According to the balance of carbon and oxygen, a decarburization model for the RH treatment has been developed. in which the influence of the mass transfer of carbon and oxygen in the liquid steel and the stirring energy (ε) in the vacuum vessel on decarburization rate has been considered. The conclusion that the volumetric coefficients of the mass transfer of carbon is proportional to ε(1.5) is drawn. Industrical experiment proves this model is reliable. The influence of some factors on decarburization rate has been obtained. which can provide directions for RH treatment The decarburization behavior of steel with RH-OB treatment is also studied. The OB-or-not curve, the optimized OB time and OB amount are discussed. 展开更多
关键词 RH treatment ultra-low carbon steel decarburization behavior mathematical model
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Effect of Radial Depth on Vibration and Surface Roughness During Face Milling of Austenitic Stainless Steel 被引量:1
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作者 申阳 陈永洁 +7 位作者 张俐 方海涛 庞佳 刘敏 王社权 马晓魁 张京 刘志林 《Transactions of Tianjin University》 EI CAS 2011年第5期336-339,共4页
This paper studies the influence of radial depth on vibration, chip formation and surface roughness during face milling of AISl3O4 austenitic stainless steel with indexable cemented carbide milling cutters. The amplit... This paper studies the influence of radial depth on vibration, chip formation and surface roughness during face milling of AISl3O4 austenitic stainless steel with indexable cemented carbide milling cutters. The amplitude of vibration acceleration increased with the increasing radial depth up to 80 mm. And the domain vibration frequency varied with the radial depth. In this paper, three types of chips were found: C shape, long shape and spiral shape. The minimum surface roughness value occurred when the radial depth equalled 40 mm in the experiment. Irregular changes of chip curl radius and chip thickness could be attributed to different numbers of alternately engaged teeth when the feed and speed were fixed. Surface roughness is related to forced vibration and chip formation. Radial depth with different numbers of alternately engaged teeth could significantly influence the forced vibration, chip formation, and surface roughness. 展开更多
关键词 austenitic stainless steel face milling radial depth VIBRATION surface roughness chip formation
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Analysis of oxide layer structure in nitrided grain-oriented silicon steel 被引量:4
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作者 Xiao-long Wu Xia Li +2 位作者 Ping Yang Zhi-wei Jia Hai-li Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第12期1531-1538,共8页
The production of low-temperature reheated grain-oriented silicon steel is mainly based on the acquired inhibitor method.Due to the additional nitriding process,a high nitrogen content exists in the oxide layer,which ... The production of low-temperature reheated grain-oriented silicon steel is mainly based on the acquired inhibitor method.Due to the additional nitriding process,a high nitrogen content exists in the oxide layer,which changes the structure of the oxide layer.In this study,the structure of the surface oxide layer after nitriding was analyzed by scanning electron microscopy(SEM),electron back-scattered diffraction(EBSD),glow discharge spectrometry(GDS),and X-ray diffraction(XRD).The size and orientation of ferritic grains in the oxide layer were characterized,and the distribution characteristics of the key elements along the thickness direction were determined.The results show that the oxide layer of the steel sample mainly comprised particles of Fe2SiO4 and spherical and lamellar SiO2,and Fe4N and fcc-Fe phases were also detected.Moreover,the size and orientation of ferritic grains in the oxide layer were different from those of coarse matrix ferritic grains beneath the oxide layer;however,some ferritic grains exhibited same orientations as those in the neighboring matrix.Higher nitrogen content was detected in the oxide layer than that in the matrix beneath the oxide layer.The form of nitrogen enrichment in the oxide layer was analyzed,and the growth mechanism of ferritic grains during the oxide layer formation is proposed. 展开更多
关键词 grain-oriented silicon steel decarburization ANNEALING OXIDE LAYER ferritic grains SILICA
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Coordinated control of carbon and oxygen for ultra-low-carbon interstitial-free steel in a smelting process 被引量:3
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作者 Min Wang Yan-ping Bao +2 位作者 Quan Yang Li-hua Zhao Lu Lin 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第12期1252-1259,共8页
Low residual-free-oxygen before fmal de-oxidation was beneficial to improving the cleanness of ultra-low-carbon steel. For ultra-low-carbon steel production, the coordinated control of carbon and oxygen is a precondit... Low residual-free-oxygen before fmal de-oxidation was beneficial to improving the cleanness of ultra-low-carbon steel. For ultra-low-carbon steel production, the coordinated control of carbon and oxygen is a precondition for achieving low residual oxygen during the Ruhrstahl Heraeus (RH) decarburization process. In this work, we studied the coordinated control of carbon and oxygen for ultra-low-carbon steel during the basic oxygen furnace (BOF) endpoint and RH process using data statistics, multiple linear regressions, and thermodynamics computations. The results showed that the aluminum yield decreased linearly with increasing residual oxygen in liquid steel. When the mass ratio of free oxygen and carbon ([O]/[C]) in liquid steel before RH decarburization was maintained between 1.5 and 2.0 and the carbon range was from 0.030wt% to 0.040wt%, the residual oxygen after RH natural decarburization was low and easily controlled. To satisfy the requirement for RH decarburization, the carbon and free oxygen at the BOF endpoint should be controlled to be between 297 × 10^6 and 400 × 10^-6 and between 574 × 10^-6 and 775 × 10^-6, respectively, with a temperature of 1695 to 1715℃ and a furnace campaign of 1000 to 5000 heats. 展开更多
关键词 low carbon steel SMELTING decarburization cleanness
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Effect of Acid Rain Erosion on Steel Fiber Reinforced Concrete 被引量:3
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作者 王艳 牛荻涛 SONG Zhanping 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第1期121-128,共8页
Acid rain can deteriorate the performance of reinforced concrete structure.Combined with the characteristics of acid rain in China,the properties of steel fiber reinforced concrete subjected to acid rain were studied.... Acid rain can deteriorate the performance of reinforced concrete structure.Combined with the characteristics of acid rain in China,the properties of steel fiber reinforced concrete subjected to acid rain were studied.The effects of steel fiber content and pH value of acid rain on the mass loss,erosion depth,neutralization depth,and splitting tensile strength of tested concrete were investigated.The mercury intrusion pore(MIP) test was used to analyze the influence of steel fiber on the acid rain resistance of concrete matrix.The results show that the corrosion of steel fiber reinforced concrete subjected to acid rain results from the combined effect of H^+ and SO4^2- in the acid rain,and steel fiber can improve the acid rain resistance of the tested concrete by improving the pore structure and enhancing the tie effect of the concrete matrix.The experiment further indicates that the optimum content of steel fiber is 1.5%compared to the various mixing proportion in this tests.The tested concrete mass loss and splitting tensile strength decrease followed by increasing as a function of corrosion time when the pH value of the simulation solution is 3 or 4,while they decrease continuously in the simulation solution at pH 2.Thanks to the tie effect of steel fiber,the spalling of concrete matrix is significantly improved,and the erosion depth and neutralization depth are less than those of conventional concrete. 展开更多
关键词 steel fiber reinforced concrete acid rain neutralization depth erosion depth
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Experiment on mechanical properties of steel fiber reinforced concrete and application in deep underground engineering 被引量:6
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作者 WANG Qi-sheng LI Xi-bing +2 位作者 ZhAO Guo-yan SHAO Peng YAO Jin-rui 《Journal of China University of Mining and Technology》 EI 2008年第1期64-66,81,共4页
Specimens of steel fiber reinforced concrete (SFRC) in volume ratios of 0%, 0.5%, 1% and 1.5% were prepared to study the supporting effect of SFRC at these diffterent volume ratios in a deep soft rock tunnel. Experi... Specimens of steel fiber reinforced concrete (SFRC) in volume ratios of 0%, 0.5%, 1% and 1.5% were prepared to study the supporting effect of SFRC at these diffterent volume ratios in a deep soft rock tunnel. Experiments with mechanical properties of compressive strength in cubic specimens, cleave strength in cylindrical specimens and four-point flexure strength of sheet metal specimens were carded out. The experimental results indicate that SFRC in a volume ratio of 1% is superior in ranking to other volume ratios in terms of technique and economics. By means of a numerical simulation, given the characteristics of soft rock deformation and damage at great depth, a new support substitution scheme of SFRC to replace plain concrete is proposed. The results of an industrial trial show that the support provided by SFRC can withstand large deformations of the surrounding rock. Good resuits have been obtained in a practical anplication. 展开更多
关键词 volume ratio steel fiber concrete mechanical performance EXPERIMENT great depth soft rock tunnel
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Age-hardening of surface aged hardening alloy 被引量:1
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作者 李忠厚 刘小萍 +1 位作者 赵金香 徐 重 《中国有色金属学会会刊:英文版》 CSCD 2000年第6期788-790,共3页
Steel T8 treated by plasma surface decarburizing was alloyed by the Xu Tec process with Co,W and Mo. An alloyed layer of Fe Co W Mo with low carbon content was formed on the surface of the high carbon steel, thus an a... Steel T8 treated by plasma surface decarburizing was alloyed by the Xu Tec process with Co,W and Mo. An alloyed layer of Fe Co W Mo with low carbon content was formed on the surface of the high carbon steel, thus an advanced gradient composite was produced. The specimens then were treated by the solution and aging treatments. The characteristics of age hardening of the alloying layer were studied. The hardness of the surface layer increases from HV200 to HV1 200 after the solution treatment at 1 190 ℃ and aging at 400 ℃ for 30 min. The results show that the surface aged high speed steel possesses not only high surface hardness, but also enough bulk strength. [ 展开更多
关键词 high CARBON steel PLASMA decarburizing age HARDENING SURFACE aged HARDENING alloy(
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Scratch behavior of high speed steels for hot rolls 被引量:1
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作者 Li Zhou Dale Sun +2 位作者 Changsheng Liu Chunguang Li Lisong Yao 《Journal of University of Science and Technology Beijing》 CSCD 2008年第4期402-406,共5页
The scratch behaviors of two high speed steels (HSS) for hot rolls were studied by a Micro-combi Tester, and the emphasis was placed on researching the relations between the microstructure and the scratch resistance... The scratch behaviors of two high speed steels (HSS) for hot rolls were studied by a Micro-combi Tester, and the emphasis was placed on researching the relations between the microstructure and the scratch resistance property of different HSS. The experimental results indicate that during the scratch process, the carbides are embedded into the matrix, the penetration depth of different HSS is closely related with the matrix hardness, i.e., the higher the matrix hardness, the better the scratch resistance property; and in the matrix, the fine, dispersive carbides are beneficial to form steady friction between the indenter and the scratched materials, but the coarser carbides are easier to fall into pieces. 展开更多
关键词 high speed steel (HSS) SCRATCH MATRIX CARBIDE penetration depth
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Microstructures and Plane Energy Spectra of X80 Pipeline Steel Welded Joints by Submerged Arc Automatic Welding 被引量:4
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作者 孔德军 YE Cundong +2 位作者 GUO Wei WU Yongzhong LONG Dan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第6期1265-1269,共5页
X80 pipeline steel was welded with submerged arc automatic welding, the microstructures, cavity sizes, fusion depths and plane scanning of chemical elements in the welded zone, fusion zone, heat affected zone and base... X80 pipeline steel was welded with submerged arc automatic welding, the microstructures, cavity sizes, fusion depths and plane scanning of chemical elements in the welded zone, fusion zone, heat affected zone and base steel were observed with OM(optical microscope) and SEM(scanning electron microscope), respectively. The experimental results show that there is main acicular ferrite in the base steel and welded zone, the microscopic structure of fusion zone is a blocked bainite, and the heat affected zone is composed of multilateral ferrite and pearlite. M-A unit of the welded zone is the main factor to strengthen the welded zone, composed of acicular ferrites. The percentage of cavities in the welded joint is less than that in the base steel, which is beneficial to increasing its mechanical performance and corrosion resistance. The fusion depth in the fusion zone and welded zone is 101.13 μm and 115.85 μm, respectively, and the distribution of chemical elements in the welded zone is uniform, no enrichment phenomena. 展开更多
关键词 X80 pipeline steel submerged arc automatic welding microstructure fusion depth plane scanning
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Experimental Investigation of Laser Surface Hardening of AISI 4340 Steel Using Different Laser Scanning Patterns 被引量:1
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作者 Baha Tarchoun Abderrazak El Ouafi Ahmed Chebak 《Journal of Minerals and Materials Characterization and Engineering》 2020年第2期9-26,共18页
Laser surface transformation hardening becomes one of the most modern processes used to improve fatigue and wear properties of steel surfaces. In this process, the material properties and the heating parameters are th... Laser surface transformation hardening becomes one of the most modern processes used to improve fatigue and wear properties of steel surfaces. In this process, the material properties and the heating parameters are the factors that present the most significant effects on the hardened surface attributes. The control of these factors using predictive modeling approaches to achieve desired surface properties leads to conclusive results. However, when the dimensions of the surface to be treated are larger than the cross-section of the laser beam, various laser-scanning patterns are involved. This paper presents an experimental investigation of laser surface hardening of AISI 4340 steel using different laser scanning patterns. This investigation is based on a structured experimental design using the Taguchi method and improved statistical analysis tools. Experiments are carried out using a 3 kW Nd: YAG laser source in order to evaluate the effects of the heating parameters and patterns design parameters on the physical and geometrical characteristics of the hardened surface. Laser power, scanning speed and scanning patterns (linear, sinusoidal, triangular and trochoid) are the factors used to evaluate the hardened depth and the hardened width variations and to identify the possible relationship between these factors and the hardened zone attributes. Various statistical tools such as ANOVA, correlations analysis and response surfaces are applied in order to examine the effects of the experimental factors on the hardened surface characteristics. The results reveal that the scanning patterns do not modify the nature of the laser parameters’ effects on the hardened depth and the hardened width. But they can accentuate or reduce these effects depending on the type of the considered pattern. The results show also that the sinusoidal and the triangular patterns are relevant when a maximum hardened width with an acceptable hardened depth is desired. 展开更多
关键词 LASER Surface HARDENING Process Experimental Investigation LASER Scanning PATTERNS AISI 4340 steel Hardness Profile Hardened depth Hardened WIDTH Design of Experiment Analysis of Variance
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Enhancement of GMI Effect in Silicon Steels by Furnace Annealing
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作者 C.Sirisathitkul P.Jantaratana 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2009年第5期619-621,共3页
The ratio and sensitivity of giant magnetoimpedance (GMI) in grain oriented silicon steels (Fe-4.5%Si) are improved after furnace annealing in air for 20 min. By annealing at 800℃, the GMI sensitivity rises from ... The ratio and sensitivity of giant magnetoimpedance (GMI) in grain oriented silicon steels (Fe-4.5%Si) are improved after furnace annealing in air for 20 min. By annealing at 800℃, the GMI sensitivity rises from 1.29%/Oe to 1.91%/Oe and the ratio increases from 237% to 294% with decreasing characteristic frequency. The results are attributable to an increase in the transverse magnetic permeability during the heat treatment. From simulation by finite element method, the GMI effect can be interpreted as the modification of the current distribution by the applied magnetic field via the transverse permeability. In the case of annealed samples,the larger transverse permeability allows a higher GMI ratio and sensitivity. 展开更多
关键词 Silicon steels Giant magnetoimpedance Furnace annealing Skin depth Transverse permeability
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The Influence of Method of Carburizing and Nitrocarburizing on the Microstructure and Properties of Tool Steels. 被引量:1
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作者 Tomasz Babul Natalia Kucharieva +1 位作者 Aleksander Nakonieczny Jan Senatorski 《材料热处理学报》 EI CAS CSCD 北大核心 2004年第5期386-389,共4页
The paper presents the results of wear and metallography tests of tool steel grades: ASTM A681, Chl2M and CH12FS per COST, AMS 6437E i BS X46Crl3, all surface hardened by the Carbo process (carburizing) and by the NiC... The paper presents the results of wear and metallography tests of tool steel grades: ASTM A681, Chl2M and CH12FS per COST, AMS 6437E i BS X46Crl3, all surface hardened by the Carbo process (carburizing) and by the NiCar process (nitrocarburizing). The thermo-chemical treatment was conducted in powder pack for a duration of 6 h (carburizing) and for 4 h in the case of nitrocarburizing. Factors investigated were: morphology, depth and microhardness of the cases obtained, their microstructure, as well as phase composition. Wear tests were conducted by the three cylinder-cone method. Wear velocity was 0.58 m/s, unit load was 50 MPa and 400Mpa, wear path was 3470 m. Oil SAE30 was applied at the rate of 30 drops per minute. 展开更多
关键词 氮碳共渗 工具钢 加工动力学 渗碳层厚度 显微硬度 磨损
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Optimum process of RH-MFB refining for ultra-low carbon steel
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作者 LiqunAi MingdongWang 《Journal of University of Science and Technology Beijing》 CSCD 2002年第5期329-333,共5页
A mathematical model was established and applied to simulate thedecarburization of RH-MFB process in Pansteel Company. Study of theeffects of w_[C]0, w_[O]0, Ar flowrate, evaluation rate the MFB lanceblowing parameter... A mathematical model was established and applied to simulate thedecarburization of RH-MFB process in Pansteel Company. Study of theeffects of w_[C]0, w_[O]0, Ar flowrate, evaluation rate the MFB lanceblowing parameters on the decarburization process was car- Ried out.The results showed that this model could give the quantitativeunderstanding of the process, especially the behavior of MFB Lanceblowing. This model has realized the optimum process of RH-MFBrefining for ultra-low carbon steels in Pansteel. 展开更多
关键词 RH process decarburization ultra-low carbon steel model
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Hump formation mechanism in gas-jet-assisted keyhole laser welding of HR-2 stainless steel
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作者 Shen Xianfeng Teng Wenhua Xu Chao 《China Welding》 EI CAS 2016年第4期14-19,共6页
Gas-jet-assisted keyhole laser welding offers the possibility of a breakthrough in the limitations of penetration depth in laser welding,which currently suffers from equipment restrictions.A gas jet of sufficient inte... Gas-jet-assisted keyhole laser welding offers the possibility of a breakthrough in the limitations of penetration depth in laser welding,which currently suffers from equipment restrictions.A gas jet of sufficient intensity to assist the keyhole should be used to obtain suppressed plasma,a deepened keyhole,and increased penetration depth.However,an excessively strong gas jet gives rise to humps.The incident angle of the keyhole-assisted gas jet is 60°,with a nozzle ahead of the laser beam.A series of experiments were carried out with different welding velocities and gas parameters by using HR-2 hydrogen-resistant stainless steel and a slab CO2 continuous-wave laser welding machine.The weld profiles can be categorized into four types,welds of traditional laser welding,welds of enhanced laser welding,undercut welds,and humping welds with increased gas pressure.A high-speed camera was employed in the experiments to monitor the formation of humps under an excessively strong gas jet.The results of analysis show that hump formation can be divided into six stages.Its main driving force is the intense turbulence of gas jet.There are two main reasons for hump formation:premature solidification of the molten pool caused by the large temperature gradient between the front and rear parts of the molten pool,and the emergence of a thin layer liquid bridge with one-directional flow under the enhanced cooling effect of excessively strong gas. 展开更多
关键词 gas-jet-assisted keyhole laser welding hump formation mechanism penetration depth hydrogen-resistance stainless steel
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Study on Diffusion Behavior of 72LX Blooms in the Decarburization Process
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作者 XU Dong ZHENG Bing +2 位作者 PANG Hongxuan WANG Xuexi ZOU Zhipeng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2022年第4期716-721,共6页
To elucidate the diffusion behavior of carbon atoms within the austenite region,the decarbonization of 72LX steel bloom was investigated.Experimental studies were performed to obtain the depth profiles of the decarbur... To elucidate the diffusion behavior of carbon atoms within the austenite region,the decarbonization of 72LX steel bloom was investigated.Experimental studies were performed to obtain the depth profiles of the decarburized layers within the temperature range of 950-1250℃.The findings show that,within a temperature range of 950-1200℃,both the depth of the decarburization layer of the grain interior(h_(in))and the depth of the decarbonization effect zone of the grain boundary(h_(b))increase concurrently with increasing holding temperatures and times and an inflection point is observed at 1200℃.By measuring the change in the sample diameter before and after the experiment,the change in the radius reduction of h_(Fe) causes by oxidation is obtained.Minimal changes are observed in h_(Fe) when the temperature is below 1050℃.As the temperature increases to 1100℃,a sudden change in h_(Fe) is observed,which corresponds to a rapid increase in oxidation.At temperatures above 1100℃,a more gradual change is observed.From the experimental results,a two-dimensional decarburization mathematical model is established and the carbon diffusion coefficients at different temperatures are obtained by simulation and regression fitting.The simulation values obtain from the carbon diffusion model matched well with the experimental values,thereby confirming the accuracy of the simulation process. 展开更多
关键词 72LX steel diffusion behavior diffusion coefficient decarburized layer
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