检索结果-南通市图书馆

Microstructure and mechanical properties of low carbon steel wires with serial and reverse-direction co.d drawing

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and steel Research International 2019年第11期26卷 1249-1256页

作者： Li-chu Zhou Meng-yuan Xia Xue-gang Min Feng Fang Jiangsu Key Laboratory of Advanced Metallic Materials Southeast UniversityNanjing 211189JiangsuChina Jiangsu Bao steel precision steel Wire co. Ltd.Nantong 226114JiangsuChina

Low carbon steel wires were prepared by two processes,serial drawing(SD)and reverse-direction drawing(RD).Effects of the two processes on microstructure and mechanical properties in steel wires were investigated by field emissio scanning electron microsco.y,electron backscatter diffraction(EBSD),X-ray diffraction and transmission electron microsco.y(TEM).Residual co.pressive stress and more low-angle grain boundaries were introduced into the steel wire by the *** a result,the RD wires exhibited a greater tensile strength when drawing strain sco.raged grain refinement and texture formation in the *** SD wires exhibited a smaller average width of the elongated ferrite grain and a higher intensity of(110)fiber texture at all drawing ***,the SD wires showed a bit greater tensile strength and 20%greater torsion performance than the RD wires at c=*** and EBSD analysis indicated that dislocation tangle was formed easily in RD wires,and it transformed into twist *** twist boundary impeded the grain refinement in the RD wires,and there were still non-fibrous grains in the RD wires even after heavy drawing.

关键词： co.d drawing Low carbon steel wire Drawing direction Mechanical property Residual stress

co.d extrusion deformation behavior of medium carbon steel after quenching and tempering

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2009年第S3期19卷 552-557页

作者：胡成亮赵震尹冠人袁兆峰徐祥龙 Department of Plasticity Technology Shanghai Jiao Tong University Jiangsu Sunway precision Forging co. Ltd.

By taking 40Cr as a specific object, co.d extrusion deformation behavior of medium carbon steel after quenching and tempering was studied by experimental works. The influence of deformation extent (10%-50%), co.e angle of die (90 °-120 °), hardness after quenching and tempering (HRC21-29) and lubricated co.dition on the forming load was analyzed. The results show that there is no central bursting and micro crack in the inner of the extruded specimen, and the forming quality is good. The double-peak phenomenon takes place at the front-end of the specimen; the double-peak index increases with deformation extent, and larger deformation can avoid the double-peak phenomenon. The deformation extent is the most important influencing factor, and the lubricated co.dition almost has no influence, which means that the phosphate co.ting plus soap process is still a proper lubrication method for co.d extrusion of medium carbon steel after quenching and tempering. By investigating the microsco.ic structure before and after deformation, the initial equiaxed grain is elongated in the extrusion direction, and this feature is more significant at the front-end of specimen.

关键词： medium carbon steel quenching and tempering co.d extrusion deformation behavior microstructure

Influence of Inactivation Treatment of Ship′s Ballast Water on co.rosion Resistance of Ship steel Plate

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and steel Research International 2013年第11期20卷 85-89页

作者： WANG Zi-xi ZHAO Jing-hui JIA Xiao-hong FANG Jian-guo ZHANG Bo DING Guo-qing Department of precision Instruments and Mechanology State Key Laboratory of TribologyTsinghua University Powder Metallurgy Division Advanced Technology and Materials Co. co.co.Shipbuilding Industry co. Qingdao Marine co.rosion Institute China Iron and Steel Research Institute Group

The effect of seawater after ultraviolet inactivation on co.rosion of a shipbuilding steel plate was investiga- ted by means of natural co.rosion potential experiments and immersion co.rosion test. The effects of natural seawater and treated seawater after ultraviolet inactivation on co.rosion of the selected steel plate samples were co.pared with each other. The results showed that there was no obvious change in the chemical co.position of treated seawater co.pared with natural seawater. The co.rosion potential slightly increased by 10 mV, whereas the co.rosion rate rose significantly by 20~. The experiments verified the naturally formed biofilm in the natural seawater for the inhi- bition of co.rosion on the shipbuilding steel plate. The possible influences of ballast water treatment on biofilm by ul- traviolet and electrolysis inactivation under the co.dition of practical usage were also investigated. And it was found that ballast water treatment methods with no co.tinuous disinfection co.ld protect original tank biofilm structure, reducing the intensity of tank co.rosion.

关键词： co.rosion ballast water biofilm

Advances in Investigation of Fe-based Glass-forming Alloy Melts

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and steel Research International 2016年第6期23卷 509-515页

作者： Hui GAO Bang-shao DONG Shao-xiong ZHOU Advanced Technology & Materials co. Ltd.Beijing Key Laboratory of Energy NanomaterialsCentral Iron & Steel Research Institute

co.tinuous precision casting is an important trend in modern *** effects in glassforming metallic liquids tremendously influence the properties of rapidly quenched ribbons;therefore,much attention has been paid to the study of Fe-based glass-forming melts at high *** investigations of these melts are categorized and *** is co.cluded that more efforts are still required to reveal the discipline of amorphization brought about by rapid quenching of Fe-based glass-forming melts.

关键词： metallic amorphous heating subsequent quenching visco.ity discipline melting glasses crystalline

Strengthening of Ultrafine Lamellar-Structured Martensite steel via Tempering-Induced Nanoprecipitation

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2022年第11期35卷 1812-1824页

作者： Xinbo Ji Liming Fu Han Zheng Jian Wang Hengchang Lu Wei Wang Mao Wen Han Dong Aidang Shan School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of High Temperature Materials and precision Forming Shanghai JiaoTongUniversityShanghai 200240China Zhejiang Institute of Advanced Materials Shanghai UniversityJiaxing 314113China Baowu steel Research Institute Baoshan Iron and Steel Co.Ltd.Shanghai 201900China

An ultrafine lamellar-structured martensite steel fabricated by heavy warm rolling(HWR)has shown an excellent co.bination of strength and *** appending tempering at 400℃to HWR,we show that the co.prehensive mechanical property of a lamellar-structured low-carbon martensite steel can be further improved to reach a yield strength of~1.8 GPa,an ultimate tensile strength of~2.0 GPa and a total elongation of~9.3%.This is achieved by tempering the HWR steel from 300 to 750℃,and the optimum tempering temperature is thus *** find that the tempered ultrafine lamellar martensite co.tains high-density nanoprecipitates dispersed within the aligned martensite laths with reduced crystallographic *** ultrahigh strength of the steel is rationalized as mainly the result of grain boundary strengthening and precipitation strengthening,which co.tribute to yield stress by 610 MPa and 440 MPa,*** good ductility is believed to be closely related to the capacity of the tempered grains to acco.modate dense dislocations upon plastic *** present thermomechanical processing provides a feasible routine for producing steels with ultrahigh-strength and good-ductility.

关键词： Low-carbon steel Heavy warm-rolling Ultrafi ne lamellar-structured martensite Precipitation strengthening Mechanical property

Microstructure evolution and mechanical anisotropy of M50 steel ball bearing rings during multi-stage hot forging

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第11期34卷 254-266页

作者： Hongwei JIANG Yanran SONG Yucheng WU Debin SHAN Yingying ZONG National Key Laboratory for precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China AECC Harbin Bearing co. LtdHarbin 150070China

This study aimed to explore the evolution of flow lines and microstructures of M50-steel bearing ring and the anisotropy of its tensile mechanical properties after Multi-Stage Hot Forging(MSHF) and subsequent spheroidizing annealing(MSHFA). To this end, the present study mainly employed stereo microsco.y, Optical Metallurgical Microsco.y(OMM), Scanning Electron Microsco.y(SEM), and Electron Backscatter Diffraction(EBSD) to characterize and analyze the workpiece at each processing stage of MSHF while performing microhardness measurement and uniaxial tensile experiment to test and analyze the mechanical properties of the workpiece. Macro-structure observation showed that the simulation results of flow lines at each stage were co.sistent with the experimental results. Microsco.ic observation showed that, after MSHF, deformation gradually became less significant along the outward radial direction of the bearing ring. After MSHFA,the microstructures of the bearing ring became uniform, whereas primary carbides did not *** mechanical properties were better in the axial direction(AD) than in the radial(RD) and circumferential directions(CD) after MSHF due to the smaller grain width. After MSHFA, the mechanical properties in the ADs and CDs were better than those in the RDs, which was due to the large cross-sectional area of carbides along the flow-line direction.

关键词： Bearing ring Flow lines Forging Mechanical anisotropy Microstructure evolution

High Boron Iron-Based Alloy and Its Modification

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and steel Research International 2009年第3期16卷 37-42,54页

作者： LIU Zhong-li CHEN Xiang LI Yan-xiang HU Kai-hua Key Laboratory for Advanced Materials Processing Technology of Ministry of Education Department of Mechanical Engineering Tsinghua University Beijing 100084 China Zhedong precision Casting co.Ltd Ningbo 315137 Zhejiang China

High boron iron-based alloy,a new kind of wear-resistant material was developed,and its microstructure and mechanical properties were studied. Moreover,the modification with V,Ti and RE-Mg was carried out as well. The results indicate that the high boron iron-based alloy co.prises a dendritic matrix and interdendritic eutectic borides under as-cast co.dition. The matrix is made up of fine pearlite,and the eutectic boride has a crystal structure of M2B （M represents Fe,Cr or Mn）. The boride has a microhardness of HV 1 425 and is distributed in the form of co.tinuous network,which is detrimental to the toughness of high boron iron-based alloy. Nevertheless,high boron iron-based alloy has a higher toughness than that of white cast iron,which is attributed to the matrix that is made up of lath-type martensite with high toughness. In order to increase the toughness further,V,Ti and RE-Mg were adopted to improve the morphology of boride. The results indicate that after modification the matrix grain is decreased in size by half,and the size of boride is also decreased,moreover,it is distributed more even though it is still co.tinuous. After heat treatment,the boride network is break up and results in the further improvement of toughness of high boron iron-based alloy.

关键词： boride modification wear-resistant material

Explainable machine learning model for predicting molten steel temperature in the LF refining process

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第12期31卷 2657-2669页

作者： Zicheng Xin Jiangshan Zhang Kaixiang Peng Junguo Zhang Chunhui Zhang Jun Wu Bo Zhang Qing Liu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China Tangshan Branch Hebei Iron and Steel Co.Ltd.Tangshan 063000China Xinjiang Bayi Iron and steel co. Ltd.Baosteel GroupUrumqi 830022China Lvliang Jianlong Industrial co. Ltd.Lvliang 032100China

Accurate prediction of molten steel temperature in the ladle furnace(LF)refining process has an important influence on the quality of molten steel and the co.trol of steelmaking *** research on establishing models to predict molten steel temperature has been ***,most researchers focus solely on improving the accuracy of the model,neglecting its *** present study aims to develop a high-precision and explainable model with improved reliability and *** eXtreme gradient boosting(XGBoost)and light gradient boosting machine(LGBM)were utilized,along with bayesian optimization and grey wolf optimiz-ation(GWO),to establish the prediction *** performance evaluation metrics and graphical representations were applied to co.pare the optimal XGBoost and LGBM models obtained through varying hyperparameter optimization methods with the other *** findings indicated that the GWO-LGBM model outperformed other methods in predicting molten steel temperature,with a high pre-diction accuracy of 89.35%within the error range of±5°*** model’s learning/decision process was revealed,and the influence degree of different variables on the molten steel temperature was clarified using the tree structure visualization and SHapley Additive exPlana-tions(SHAP)***,the explainability of the optimal GWO-LGBM model was enhanced,providing reliable support for prediction results.

关键词： ladle furnace refining molten steel temperature eXtreme gradient boosting light gradient boosting machine grey wolf op-timization SHapley Additive exPlanation

Effect of Direct Aging on co.rosion Behavior of AlSi10Mg Alloy Fabricated by Laser Powder Bed Fusion

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 266-282页

作者： Zhen Zhang Zhanyong Zhao Xiaofeng Li Beibei Wang Peikang Bai Shanxi Key Laboratory of co.trolled Metal Solidification and precision Manufacturing School of Materials Science and EngineeringNorth University of ChinaTaiyuan030051China Technical Center Taiyuan Iron and Steel(Group)Co.LtdTaiyuan030003China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China

Effect of direct aging of 170℃on co.rosion behavior of laser powder bed fused AlSi10Mg(LPBF-AlSi10Mg)was studied by microstructure analysis,electrochemical analysis and X-ray photoelectron *** results show that direct aging of 170℃has little effect on melt pool and Si cellular structure,but promotes the precipitation of nano-Si particles and releases the residual *** increasing aging time from 0 to 4 h to 24 h,the co.rosion property of the LPBF-AlSi10Mg is deteriorated,which is evidenced by increased co.rosion current density and decreased pitting potential and polarization *** increasing the aging time,the thickness of the oxide film formed on surface of the LPBF-AlSi10Mg *** Si co.tent of the oxide film of the sample aging for 4 h is the lowest,9.42 at.%,and it is the highest,18.62 at.%,for the sample aging for 24 *** electrochemical noise analysis reveals that the middle-frequency co.tribution of the Hilbert spectrum is responsible for the deteriorated co.rosion performance,which co.responds to metastable pitting initiated by nano-Si particles.

关键词： Laser powder bed fusion AlSi10Mg Direct aging co.rosion