WorldWideScience

Sample records for 6-5-2 high-speed steel

  1. Effect of deep cryogenic treatment on substructure of HS6-5-2 high speed steel

    J. Jeleńkowski

    2010-11-01

    Full Text Available Purpose: The purpose of this study was using of transmission electron microscopy (TEM and differential scanning calorimetry (DSC in order to reveal the changes in substructure of speed steel made with deep cryogenic treatment (DCT, in comparison with substructure formed by conventional heat treatment for secondary hardness.Design/methodology/approach: The HS6-5-2 high speed steel was heat treated in a conventional mode for secondary hardness or was processed in a mode with use of DCT, with and without next tempering. Transmission electron microscopy and scanning electron microscopy observations were carried out. Studies of thermal stability in range of temperatures from -196 °C to 400 °C were performed using differential scanning calorimetry (DSC.Findings: Observations made with aid of SEM-TEM microscope revealed the presence of high density of globular clusters situated at dislocations, and precipitations of the fine carbide plates, located in twinned crystals of martensite. Thermal analysis (DSC showed an occurrence of higher exothermic effects in specimens treated with use of DCT, than in specimens heat treated conventionally. In steel samples after quenching and DCT the additional exothermic effect was observed. Electron diffraction in TEM studies of these specimens allowed to observe reflections of which indexing exhibited that the precipitated carbide phase has crystallographic structure of B1 type.Research limitations/implications: Extremely high dispersion of carbide phases and a high state of stress that accompanies the stage of precipitation, make difficult the identification of the lattice structure of precipitations, its crystallographic relationships and the degree of coherence with the matrix. Identification of the type of carbides (ε, η, B1, and others and their coherence with matrix become time-consuming. This important issue requires detailed studies using high-resolution microscopes. Conditions of the early stage of the

  2. Structure of the gradient carbide steels of HS 6-5-2 high-speed steel matrix

    Torralba, J. M.; G. Matula; A. Kloc-Ptaszna; L.A. Dobrzański

    2007-01-01

    Purpose: The goal of this work is to obtain gradient carbide steels based on a high-speed steel reinforced wittungsten carbide.Design/methodology/approach: The materials were fabricated using the conventional powder metallurgmethod. The gradient carbide steels was fabricated by mixing high-speed steel with WC powders. The uniaxiapressing before sintering was used for manufacturing the materials, consisting in compacting the powder in closed die, and subsequent sintering. The sintered test pie...

  3. Structure and properties of the gradient tool materials based on a high-speed steel HS6-5-2 reinforced with WC or VC carbides

    L.A. Dobrzański; A. Kloc-Ptaszna

    2009-01-01

    Purpose: This paper concerns manufacturing and researching a new group of the gradient tool materials, manufactured by a conventional powder metallurgy method, consisting in compacting a powder in a closed die and sintering it.Design/methodology/approach: The materials were obtained by mixing the powders of the HS6-5-2 high-speed steel, tungsten carbide (WC), and vanadium carbide (VC). The mixes were poured one by one into the die, yielding layers with the gradually changing volume ratio of c...

  4. Structure and properties of the gradient tool materials based on a high-speed steel HS6-5-2 reinforced with WC or VC carbides

    L.A. Dobrzański

    2009-12-01

    Full Text Available Purpose: This paper concerns manufacturing and researching a new group of the gradient tool materials, manufactured by a conventional powder metallurgy method, consisting in compacting a powder in a closed die and sintering it.Design/methodology/approach: The materials were obtained by mixing the powders of the HS6-5-2 high-speed steel, tungsten carbide (WC, and vanadium carbide (VC. The mixes were poured one by one into the die, yielding layers with the gradually changing volume ratio of carbides within the high-speed steel matrix. Structural research by using the scanning and transmission electron microscopes, x-ray microanalysis and density, hardness and porosity tests, were performed. Structure and hardness of selected materials after heat treatment were also investigated.Findings: On the basis of the results of the research, it was found that it was possible to obtain gradient materials by the powder metallurgy methods, in order to ensure the required properties and structure of the designed material. It was shown that the new sintered graded materials were characterized by a multiphase structure, consisting of ferrite, primary carbides of the high speed steel, of the MC and M6C type, and dependently of the reinforcement phase, of the tungsten carbide WC or the vanadium carbide VC, which were introduced into the material, in the form of powder. Additionally in the structure of the WC-reinforced materials the W2C phase occurs. The gradient tool materials reinforced with the WC carbide were characterized by a higher hardness, and a lower porosity in relation to the materials reinforced with the VC carbide. It was found that the desired structure and properties (density, porosity and hardness had the material containing 25% of the WC carbide in the surface layer, after sintering at the temperature 1210oC, for 30 minutes. The heat treatment application causes a significant increase of the surface layer hardness of the material. The highest

  5. Structure and properties of the gradient tool materials of unalloyed steel matrix reinforced with HS6-5-2 high-speed steel

    Torralba, J. M.; G. Matula; A. Kloc-Ptaszna; L.A. Dobrzański

    2007-01-01

    Purpose: The goal of this work is to obtain the gradient materials based on the non-alloyed steel reinforced high-speed steel using the pressureless formed method.Design/methodology/approach: The non-alloyed steel was fabricated by mixing iron powders with graphite. The unalloyed steel contains 0.5% carbon. The pressureless powder forming was used for manufacturing the materials. Findings: It was found out, basing on the hardness tests, that the layer built of steel without any alloy elements...

  6. Influence of heat-treatment on structure and properties of the high-speed steel HS6-5-2 and HS12-1-5-5 produced by PIM process

    On the basis of investigations of high-speed steel formed out of polymer powder slurry (PIM) and their comparison with results of investigations of pressed and sintered steels (PM), hot isostatic pressed (HIP) and conventional it has been shown that the structure of all examined high-speed steels in quenched state is martensite, retained austenite and primary carbide MC and M6C types partially dissolve in solid solution during austenitizing. Higher carbon concentration causes increase of the retained austenite portion in those (PIM) steels and lower hardness after quenching in relation to the same grades manufactured by other method. A high retained austenite portion after quenching falls after tempering at the temperature of 600 oC to 10% for HS6-5-2 and 8% for HS12-1-5-5 PIM steel results in hardness increase after tempering at this temperature to the maximum values equalled 63.2 HRC for HS6-5-2 steel quenched from temperature 1180 oC, and tempered at 600 oC and hardness 67.6 HRC for H12-1-5-5 steel quenched from temperature 1210 oC and tempered at 600 oC, respectively. Outcarried tribological investigations have shown that experimental steels are characterised by high abrasive wear in comparison with steels manufactured in the other methods. (author)

  7. Comparing the tribiological resistance of the tool steel C90 and HS 6-5-2 remelted with the electric arc

    A. Dziedzic

    2010-01-01

    Full Text Available There have been the results of the tribiological research presented of the tool, non-alloy steel C90 and high speed steel HS 6-5-2. The comparison has been presented due to the similar content of the carbon in both steels. The tribiological research were conducted in the conditions of the technically dry friction on a testing machine of the type pin on disc T-01M. The tribiological research showed the similar intensity of tribological wear of the steel C90 and HS 6-5-2 remelted with the electric arc. During the friction there was the abrasion and adhesive wear.

  8. The kinetics of phase transformations during the tempering of HS6-5-2 high–speed steel

    P. Bała

    2006-08-01

    Full Text Available Purpose: The reasons for write this paper was described the kinetics of phase transformations during temperingof hardened HS6-5-2 high-speed steel. Moreover, the influence of the heating rate on the retained austenitetransformation.Design/methodology/approach: CHT diagram was with dilatometric method determined. The influence of theheating rate on the retained austenite transformation as well as the results of threefold tempering at 560°C werealso determined.Findings: During heating of the samples of the quenched HS6-5-2 steel the occurrence of 4 principaltransformations was determined. These are: precipitation of ε carbide, M3C precipitation, transformation ofretained austenite and precipitation of alloy carbides of MC and M2C type. It was shown that in the quenchedhigh-speed steels a part of retained austenite is already transformed during heating for tempering, but itssignificant part is transformed only during cooling after tempering as well as during consecutive heatings fortemperings.Research limitations/implications: The new CHT diagram of investigated steel was determined.Practical implications: The obtained CHT diagram may be used to design new technologies of tempering ofthis steel.Originality/value: The new CHT diagram

  9. The comparison of the structure and microhardness of the tool steel C90 and HS 6-5-2 remelted with the electric arc

    A. Dziedzic

    2010-04-01

    Full Text Available The examination of the structure and microhardness of surface layer of C90 non-alloy steel and HS 6-5-2 high speed steel after electric arc treatment are presented in the paper. The comparison has been presented due to the similar content of the carbon in both steels. The structure of the remelted zone of the steel C90 before the conventional tempering consists of the cells, dendritic cells surrounded with the cementite, there is a plate martensite and retained austenite inside them, whereas the structure of the steel HS 6-5-2 is consistuted with cells, dendritic cells and dendrites surrounded with the eutectic system, inside of which there is a plate martensite and retained austenite. Such structure is characterized by the similar microhardness (790-800 HV0,065 and intensity of the tribiological wear. The tempering causes the decrease of the microhardness in non-alloy steel and the increase of the microhardness in high speed steel.

  10. Surface Treatment of High Speed Steel Tools

    タカハシ, ヒサオ; Hisao, TAKAHAASHI

    1997-01-01

    This paper reveals to cutting performance on 3 kinds of high speed steels throw away tips (including made by powder metallurgical process), which are compared surface treated tips by means of the coating process PVD-TiN (physical vapor deposition by the arc ion plating method) with untreated conventional tips. The results are as follows: "X"tips by name have the highest hardness and performance on continuous cutting than the others, but they have the lowest toughness and larger chipping on in...

  11. Progress in the development of niobium alloyed high speed steel

    The development of economy-grades of niobium alloyed high speed steel is described. Both the metallurgical concepts behind the steel design and the results of performance tests are presented. (Author)

  12. Temperature distribution of high speed tool steel rod during high speed hot rolling procedure

    The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod

  13. Temperature distribution of high speed tool steel rod during high speed hot rolling procedure

    Jeong, Hyo Tae; Lee, Soo Yeon; Ha, Tae Kwon [Kangnung National University, Gangneung (Korea, Republic of); Jung, Jae Young [Research Institute of Inderstrial Science and Technology, Pohang (Korea, Republic of)

    2008-03-15

    The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod.

  14. Spray forming high speed steel - properties and processing

    The potential of spray forming (SF) for microstructural refining can be attractive to the production of high speed steels. The refined as-cast structure may lead to important improvements of material properties, compared to conventionally cast materials. The present work aimed to compare the properties of AISI M3:2 high speed steel produced through spray forming and conventional casting. Also, the processing of SF billet is considered, specifically the hot working conditions and its relation to carbide size. A round 400 mm diameter SF billet was produced using a twin atomiser. Characterisation was performed in the as-cast structure and after hot working to 116 mm squared bars and 11 mm diameter round bars. The results show that, compared to conventionally cast high speed steel, the SF material has higher isotropy in toughness due to its less oriented carbide distribution. Regarding processing procedures, time and temperature employed in heating before hot working also affect the microstructure of SF material

  15. Spray forming high speed steel - properties and processing

    Mesquita, Rafael Agnelli; Barbosa, Celso Antonio

    2004-10-10

    The potential of spray forming (SF) for microstructural refining can be attractive to the production of high speed steels. The refined as-cast structure may lead to important improvements of material properties, compared to conventionally cast materials. The present work aimed to compare the properties of AISI M3:2 high speed steel produced through spray forming and conventional casting. Also, the processing of SF billet is considered, specifically the hot working conditions and its relation to carbide size. A round 400 mm diameter SF billet was produced using a twin atomiser. Characterisation was performed in the as-cast structure and after hot working to 116 mm squared bars and 11 mm diameter round bars. The results show that, compared to conventionally cast high speed steel, the SF material has higher isotropy in toughness due to its less oriented carbide distribution. Regarding processing procedures, time and temperature employed in heating before hot working also affect the microstructure of SF material.

  16. The influence of arc plasma electric and laser treatment on the structure and properties of the high speed steel

    W. Bochnowski

    2009-07-01

    Full Text Available The examination of the structure, hardness and abrasion resistance of surface layer of high speed steel: HS 2-10-1-8, HS 6-5-2 and HS 10-2-5-8 after arc plasma and laser welding are presented in the paper. They are compared with the properties obtained after conventional hardening. Diode laser of continuous operation and GTAW (Gas Tungsten Arc Welding method were used. As a result of concentrated energy beam treatment applied to a steels surface layer, the structures characteristic of rapid solidification / crystallization process were obtained. The treatment of the steel by arc plasma electric with a single remelted track about 7 mm width does not lead to growth of the mechanical and tribological properties of high speed steels. The growth of microhardness as well as low the coefficient Archard of the high speed steel after remelting on the surface single track about 6 mm width by diode laser using can be obtained.

  17. Comparison of the PVD gradient coatings deposited onto X40CrMoV5-1 and HS6-5-2 tool steel substrate

    K. Lukaszkowicz

    2008-03-01

    Full Text Available Purpose: The main aim of this research was investigation and comparison of selected properties of gradient coatings TiCN and AlSiCrN. In this paper both coatings were deposited by cathode arc evaporation physical vapour deposition (CAE-PVD method onto high speed steel HS6-5-2 and hot work tool steel X40CrMoV5-1.Design/methodology/approach: Observations of surface and structures of the deposited coatings were carried out on cross sections in the scanning electron microscope. The phase composition of the investigated coatings was determined by means of the X-ray diffractometer. Tests of the coatings’ adhesion to the substrate material were made using the scratch test. The microhardness tests of coatings were made with the ultra microhardness tester.Findings: The hard PVD gradient coatings deposited by cathodic arc evaporation method demonstrate the high hardness, adhesion and wear resistance. The critical load LC2, which is in the range 35-67 N, depends on the coating type and material substrate. The values of friction coefficient for the investigated coatings are changing within the range of 0.08-0.25.Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the coatings.Originality/value: It should be emphasized that the mechanical properties of the PVD coatings obtained in this work are very encouraging and therefore their application for products manufactured at mass scale is possible in all cases where reliable, very hard and abrasion resistant coatings, deposited onto tools steel substrate are needed.

  18. Surface modifications of upgraded high-speed tool steel

    The SW7M high-speed tool steel of composition Fe (80%), Mo (5%), Cr (4%), V (2%) and C (1%) was studied by conversion electron Moessbauer spectroscopy at 293 K. The specimen consists mainly of α-Fe, martensite and austenite grains. The unwanted fraction of austenite was reduced by polishing the sample in an external magnetic field. At elevated temperatures, the SW7M steel exhibits a selective oxidation of its fraction. The corrosion rate is sigificantly reduced by N and Ti low-energy ion bombardment. (orig.)

  19. Structure and properties of FGM manufactured on the basis of HS6-5-2

    G. Matula; L.A. Dobrzański

    2006-01-01

    Purpose: It has been demonstrated in the paper structure and properties of tool gradient materials manufactured by powder metallurgy on the basis of high speed-steel HS6-5-2 type.Design/methodology/approach: Light microscope, SEM, image analysis, microhardness tests, density examination.Findings: Basing on the investigations of the HS6-5-2 type high-speed steels reinforced with ceramics particles fabricated with Powder Metallurgy it was found that density of sintered samples depend on reinfor...

  20. Development of centrifugal casting high speed steel rolls

    Hanguang Fu; Aimin Zhao; Jiandong Xing

    2003-01-01

    The present study aims at developing the high speed steel (HSS) as roll materials to replace the traditional roll materials such as the alloy cast iron and powder metallurgical (PM) hard alloy. The HSS roll billet was formed by centrifugal casting, and the billet was rough machined after soften annealing heat treatment, then it was quenched and tempered to get suitable hardness and toughness. After that the HSS roll was finish machined to the final dimension of φ285 mm in the outer diameter, φ160 mm in the inner diameter and 120 mm in width and its surface hardness was tested. Finally the HSS roll was used in high speed wire rod mill. The test results show that a high and homogeneous hardness can obtain on the work surface of HSS rolls, the surface hardness is 63-65HRC and its variation is smaller than 2HRC. The impact toughness of this kind of HSS is about 16 J/cra2. The results of on-line service investigation in high speed wire rod mill indicate that the HSS rolls have excellent wear resistance, the steel rolling quantity per mm of HSS rolls is 3120 t, the service life-span of HSS rolls is 4 times longer than that of high chromium cast iron rolls and it is close to that of the PM hard alloy rolls. The manufacturing burden of HSS rolls is obviously lower than that of the PM hard alloy rolls, it is only 25% of that of the PM hard alloy rolls.

  1. A study on centrifugal casting of high speed steel roll

    2004-01-01

    High speed steel (HSS) rolls can replace traditional rolls such as alloyed cast iron rolls and powder metallurgical (PM) hard alloy rolls. The main reasons for the replacement are that the wear resistance of low-cost alloyed cast iron rolls is poor and the cost of high-quality PM hard alloy rolls is very high. By means of centrifugal casting, HSS rolls having excellent wear resistance have been manufactured. The hardness of the HSS roll is 65~ 67 HRC, the range of variation is smaller than 2 HRC and its impact toughness is 15 J/cm2. The wear rate of HSS rolls used in the pre-finishing stands of high-speed hot wire-rod rolling mill reaches 2.5 × 10-4 mm per ton steel. Furthermore, the manufacturing cost of HSS rolls is significantly lower than that of PM hard alloy rolls; it is only 30 percent of that of PM hard alloy rolls.

  2. Structure and properties of HS6-5-2 type HSS manufactured by different P/M methods

    G. Matula; L.A. Dobrzański; Herranz, G.; Varez, A.; B. Levenfeld; Torralba, J. M.

    2007-01-01

    Purpose: It has been demonstrated in the paper structure and properties of of high speed-steel HS6-5-2 type manufactured by different method of powder metallurgy.Design/methodology/approach: Light microscope, SEM, image analysis, hardness tests, density examination, transverse rupture strength tests, analysis of chemical composition by LECO apparatus.Findings: Basing on the investigations of the HS6-5-2 type high-speed steels reinforced with ceramics particles fabricated with Powder Met...

  3. Influence of the Magnetic High-speed Steel Cutting Tool on Cutting Capability

    2002-01-01

    The high-speed steel cutting tool has advantaged i n modern cutting tool for its preferable synthetical performance, especially, in a pplication of complicated cutting tools. Therefore, the study of the high-speed steel cutting tools that occupied half of cutting tools has become an importa nt way of studying on modern cutting technology. The cutting performance of hi gh speed-steel cutting tools will be improved by magnetization treating method. Microstructure of high-speed steel will be changed as a ...

  4. Effect of quenching temperature on structure and properties of centrifugal casting high speed steel roll

    Fu Hanguang; Cheng Xiaole; Du Zhongze

    2009-01-01

    The critical points and time-temperature-transformation (TTT) curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study. The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel (HSS) roll has been investigated using scanning electron microscopy (SEM), light optical microscopy (LOM) and X-ray diffraction (XRD) as well as us...

  5. The study of high speed fine turning of austenitic stainless steel

    W.S. Lin

    2008-01-01

    Purpose: The purpose of this research paper is focused on the surface roughness variation in high speed fine turning of the austenitic stainless steel.Design/methodology/approach: A series of experimental tests have been done to evaluate the possibility of high speed fine turning of the austenitic stainless steel from the surface roughness variation and machining stability.Findings: It was found that, the smaller the feed rate, the smaller the surface roughness value. But when the feed rate s...

  6. The electrogas and electroslag multipass high speed welding of nuclear pressure vessel steels

    High-speed electroslag and electrogas welding of 15 Mn Ni63 steel plates to achieve high strength and toughness joints for reactor pressure vessels are described. Mechanical testing of overheating-resistant, brittle fracture resistant low alloy steels is discussed. (UK)

  7. Nonmetallic Inclusion Control of 350 km/h High Speed Rail Steel

    ZHAO Ke-wen; ZENG Jian-hua; WANG Xin-hua

    2009-01-01

    Inclusion has an important effect on quality of high speed rail steel.In consideration of the lower acceptance percentage of the inclusion and its constraint against the requirement for large scale production of 350 km/h high speed rail steel in Panzhihua Iron and Steel (Group) Co,the technology of nonmetallic inclusion control for 350 km/h high speed rail steel was studied.An optimized model of the argon-blowing in ladle furnace (LF),the control of the components of the ladle slag,and the technique of calcium treatment for the molten steel was brought forward.Using the researched technology,the removal ratio of the inclusion was increased and the components,distribution,and shape of the inclusion in the rail steel were changed,which resulted in a reduction in the average total oxygen content to 10.17×10-6 and an increase in the comprehensive acceptance percentage of the nonmetallic inclusion from 48.21% to 98.1%.Test has shown that this metallurgical technology can meet the requirement for large scale production of 350 km/h high speed steel in Panzhihua Iron and Steel (Group) Co.

  8. Analysis of carbides and inclusions in high speed tool steels

    Therkildsen, K.T.; Dahl, K.V.

    2002-01-01

    The fracture surfaces of fatigued specimens were investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). The aim was to quantify the distribution of cracked carbides and non-metallic inclusions on the fracturesurfaces as well as on polished cross...... sections. The specimens were made of Böhler P/M steel grade 390s and 690s in both micro-clean and conventional grades. The results show that the content of non-metallic inclusions are higher in the conventionalgrades than in the microclean grades, but there were found to be no link between non......-metallic inclusions and the crack initiation. Surprisingly, no differences were found between the carbide size distributions of the micro-clean and conventional grades.Also, the distribution of the fractured carbides was found to be the same regardless of steel type, manufacturing method or location on the specimen....

  9. ECR plasma assisted nitridation of high speed steel

    Conventional industrial nitridation techniques for tool steel include DC plasma and gas phase reactions. Nitridation by Electron Cyclotron Resonance plasma (ECR) of N2 + H2 has yielded higher case depth of nitrided layer on tool steel in lower time as compared to Industrial nitridation. This is mainly due to the higher energies as well as densities of ions in ECR plasma. The substrates were mounted on a heater held in the upstream of the N2 + H2 plasma zone. The heater and correspondingly the samples were heated for temperatures 450 deg and 550 deg. during plasma treatment. A negative bias of -300 V with respect to the chamber was given to the sample. The samples were treated for a time of 90 minutes

  10. Solidification of hipereutectoid high speed steel for rolls

    J. Gontarev

    2011-01-01

    Full Text Available This work presents results of microstructural development through solidification, heat treated processes and characterization of two low-alloyed hypereutectoid alloys, emphasizing the effects of the alloy chemical composition. Samples of different compositions were prepared by melting in the induction furnace. The microstructural difference of the different HSS steels will affect the performance of the end products. The main features of the as cast microstructure are the distribution and morphology of eutectic carbides which have been obtained through progress in alloy design concerning the type, morphology, and the volume fraction of the eutectic carbides. Samples were characterized by optical and Scanning electron microscopy.

  11. Spark Plasma Co-Sintering of Mechanically Milled Tool Steel and High Speed Steel Powders

    Massimo Pellizzari

    2016-06-01

    Full Text Available Hot work tool steel (AISI H13 and high speed steel (AISI M3:2 powders were successfully co-sintered to produce hybrid tool steels that have properties and microstructures that can be modulated for specific applications. To promote co-sintering, which is made difficult by the various densification kinetics of the two steels, the particle sizes and structures were refined by mechanical milling (MM. Near full density samples (>99.5% showing very fine and homogeneous microstructure were obtained using spark plasma sintering (SPS. The density of the blends (20, 40, 60, 80 wt % H13 was in agreement with the linear rule of mixtures. Their hardness showed a positive deviation, which could be ascribed to the strengthening effect of the secondary particles altering the stress distribution during indentation. A toughening of the M3:2-rich blends could be explained in view of the crack deviation and crack arrest exerted by the H13 particles.

  12. Wear mechanisms in powder metallurgy high speed steels matrix composites

    The development of metal matrix composites has a major interest for automotive and cutting tools industries since they possess better mechanical properties and wear resistance than corresponding base materials. One of the manufacturing methods for these materials includes processing by powder metallurgy techniques. in this case, blending of both, base material and reinforcement powders constitute the most important process in order to achieve a homogeneous distribution of second phase particles. in the present work, composite materials of M3/2 tool steel reinforced with 2.5,5 and 8 vol% of niobium carbide have been prepared. In order to ensure a homogeneous mix, powders of both materials were mixed by dry high-energy mechanical milling at 200 r.p.m. for 40 h. After a recovering annealing, two routes for consolidate were followed die pressing and vacuum sintering, and hot isostatic pressing (HIP). Pin-on-disc tests were carried out to evaluate wear behaviour in all the materials. Results show that ceramic particles additions improve wear resistance of base material. (Author) 9 refs

  13. Current Developments of Alloyed Steels for Hot Strip Roughing Mills : Characterization of High-Chromium Steel and Semi-High Speed Steel

    LECOMTE-BECKERS, Jacqueline; Sinnaeve, Mario; Tchuindjang, Jérôme Tchoufack

    2012-01-01

    Two alloys grades for work rolls used in the roughing stand of Hot Strip Mill - high chromium steel (HCS) and semi-high-speed steel (semi-HSS), In this paper, the new semi-high-speed steel grade is studied

  14. Influence of form method on structure and properties of high speed steels

    In the paper it has been demonstrated that experimental steels of the HS 6-5-2 and HS 12-1-5-5 type made by the polymer-powder slurry forming (PIM) characterized by a lower sintering temperature, in relation to the same steel grades manufactured by compaction and sintering (PM). It has been found out that higher density, more homogeneous structure with fine precipitations of carbide phases are obtained during sintering of steels formed out of the slurry in the atmosphere of inert gases. (author)

  15. HIGH SPEED STEEL TOOL WEAR AFTER WOOD MILLING IN THE PRESENCE OF HIGH TEMPERATURE TRIBOCHEMICAL REACTIONS

    B. Porankiewicz; P. Iskra; Jóźwiak, K.; Tanaka, C.; W. Zborowski

    2008-01-01

    Wear patterns were analyzed for High Speed Steel (HSS) SKH51 cutting tools after milling wood of four wood species having very different High Temperature Tribochemical Reactions (HTTR), wood density and very low hard mineral contamination (HMC). The experimental results showed that the HTTR can be an important factor influencing acceleration of cutting tool wear.

  16. Implantation profiles of nitrogen and titanium in a low energy bombarded high speed tool steel

    Effects of low-energy implantation on the properties of subsurface layers of high speed tool steel are investigated. The depth profiles of nitrogen and titanium are measured. The results are discussed in terms of adhesion of hard thin film (TiN) to the implanted surface. (author)

  17. Some metallurgical aspects of chips formed in high speed machining of high strength low alloy steel

    Adiabatic shear bands and white layers induced during high speed cutting of 30CrNi3MoV steel were investigated by scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The results show that some non-diffusional martensitic phase transformation and dynamic recrystallization might take place in the adiabatic shear bands and white layers within the chips

  18. Scanning electron microscopy and transmission electron microscopy microstructural investigation of high-speed tool steel after Nd:YAG pulsed laser melting.

    Kac, S; Kusinski, J; Zielinskalipiec, A; Wronska, I

    2006-10-01

    This article presents the microstructure of a pulsed Nd:YAG laser-melted high-speed steel, namely HS6-5-2. The high chemical homogeneity and fine structure of the melted zone was attributed to high cooling rates due to the short duration of interaction with the Nd:YAG pulsed laser radiation and the relatively small volume of the melted material. The structure obtained in the surface layer after laser melting has a high level of hardness and shows improved wear resistance. PMID:17100909

  19. Reducing the content of alloying elements in high-speed steel during heating in salt baths

    Barium chloride salt baths are primarily used for the high-temperature quench heating of a tool formed from high-speed steels. If the barium chloride melt should have a decarbonizing effect on the surface components that are heated in it, the authors maintain that it may also affect the content of alloying elements in the surface layers of high-speed-steel components that are heated in it. Commercial salt baths with a rectifier -- chemically pure magnesium fluoride -was used for the investigation. Cooling was accomplished in a caustic melt. Analysis of the results of investigation of the molybdenum, tungsten, and cobalt distributions in steel R9M4K8 as well as the tungsten and cobalt distributions in steel R9K5 indicated that the cobalt content does not diminish on heating to 12300C. A decrease in molybdenum content occurs in the surface layers during the quench heating of a tool formed from high-speed tungsten-molybdenum steel in a barium chloride salt bath after the required heating time, while a decrease in the tungsten content takes place with more prolonged hold times. It is shown to be possible to reduce or completely eliminate loss of alloying elements in the surface layers of a high-speedsteel tool during heat treatment when magnesium fluoride in combination with silicon carbide additives is used as a rectifier

  20. Characterization of Tool Wear in High-Speed Milling of Hardened Powder Metallurgical Steels

    Fritz Klocke

    2011-01-01

    Full Text Available In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC and the high speed steel HS 6-5-3 PM (S790 Microclean/64 HRC. The milling tests were performed at effective cutting speeds of 225, 300, and 400 m/min with a four fluted solid carbide ball-end mill (0 = 6, TiAlN coating. It was observed that by means of analytically optimised chipping parameters and increased cutting speed, the tool life can be drastically enhanced. Further, in machining the harder material HS 4-2-4 PM, the tool life is up to three times in regard to the less harder material HS 6-5-3 PM. Thus, it can be assumed that not only the hardness of the material to be machined plays a vital role for the high-speed dry-hard cutting performance, but also the microstructure and thermal characteristics of the investigated powder metallurgical steels in their hardened state.

  1. The structure and properties of PVD coated PM high-speed steels

    Dobrzanski, L.A.; Adamiak, M. [Inst. of Engineering Materials and Biomaterials, Silesian Univ. of Technology, Gliwice (Poland)

    2001-07-01

    The paper presents results of investigations concerning structure and properties of TiN and Ti(C,N) coatings deposited onto PM high speed steels of the P 6-5-3 and P 6-5-3-8 types produced by the ASEA-Stora process. It has been confirmed that TiN and Ti(C,N) coatings had very good adherence to the substrate, low friction coefficient and high hardness. The structure of coatings is dense and columnar shaped. The erosion resistance of sintered high speed steels coated in the PVD process is extended and limited to the coating material only during the initial period - unlike in the case of uncoated steels where an erosion rate is constant from the very beginning. (orig.)

  2. High Speed Turning of H-13 Tool Steel Using Ceramics and PCBN

    Umer, Usama

    2012-09-01

    H-13 is the toughest tool steel used in machined die casting and forging dies. Due to its extreme hardness and poor thermal conductivity high speed cutting results in high temperature and stresses. This gives rise to surface damage of the workpiece and accelerated tool wear. This study evaluates the performance of different tools including ceramics and PCBN using practical finite element simulations and high speed orthogonal cutting tests. The machinability of H-13 was evaluated by tool wear, surface roughness, and cutting force measurements. From the 2D finite element model for orthogonal cutting, stresses and temperature distributions were predicted and compared for the different tool materials.

  3. Study of dual implantation into high speed steel by Ti+ and C+ ions

    The implantation of titanium plus carbon ion into W9Mo3Cr4V high speed steel was conducted in order to improve tribological properties of the steel. Meanwhile the influence of altering Ti and C implantation order on improvements of surface properties of the steel was also investigated. The hardness of implanted surface was evaluated by an ultramicrohardness test and unlubricated friction and wear tests were performed in a reciprocating ball-on-disk-test. It is shown that titanium plus carbon dual implantation increase the microhardness by 25-50 % and decrease the friction coefficient by a factor of 3 over the unimplanted sample

  4. Contribution of heat treatment to the stress state in high speed steels subjected to conventional hardening and diode laser modification

    The required high properties of high speed steels are achieved by complex heat treatment comprising hardening and tempering leading to primary and secondary carbides distributed in a martensitic matrix. Examinations were performed on steels of grades HSS 6-5-2, HSS 2-10-1-8 produced using conventional metallurgy and HSS 10-2-5-8 produced by application of powder metallurgy. Hardness maximum was stated after tempering at about 530 oC when coherent precipitates of the secondary carbides of the MC and M2C types strengthened the martensitic matrix. Loosing of coherency by these carbides led to hardness loss as well as diminishing of residual stresses. Experiments comprising hardness measurements, XRD studies of phase constitution with focus on type of carbide and amount of retained austenite were carried out. Unique residual stresses examination in relation to heat treatment was performed, as well as, an energy filtered TEM (EFTEM) study of secondary carbides of nanometer sizes, difficult to observe using conventional method, were applied. All HSS under examination were subjected diode laser modification by remelting. (author)

  5. Study on high speed tension property of B-grade bulletproof steel

    Ma Mingtu; Fang Gang; Feng Yi

    2014-01-01

    In this paper,the high speed tension experiments have been performed on ultra high strength bullet-proof steel. The specimen were cut from B-grade bulletproof steel sheet after hard-module quenching with thick-ness of 2.3 mm. The mechanical properties at strain rates of 0.001 s-1,0.01 s-1,0.1 s-1 and 1 s-1 were carried out on MTS810,while those at higher strain rates of 200 s-1,500 s-1 and 1 000 s-1 were tested on HTM5020 high speed tension tester and Hopkinson bar. The data from the high speed tension experiments were fitted via Johnson-Cook constitutive equation,and the fracture surface of each specimen was analyzed by scanning elec-tron microscope (SEM). The results indicate that,the shoot resistance capability of bulletproof steel is closely related to its strength,thickness and flow behaviors under high strain rate. The shoot resistance will be im-proved in the case of higher strength and better matching between strength and elongation. The Johnson-Cook constitutive equation fitted via experimental data provides fundament to numerical simulation. With the increase of strain rate,the size and depth of dimple trend to decrease and the depth of dimple changes less in steel with lower strength and higher elongation. The SEM analysis of fracture aspect is of benefit for further understanding of deformation and fracture mode under high strain rate.

  6. A preliminary investigation on selective laser melting of M2 high speed steel

    Liu, Zhonghong; Chua, Chee Kai; Leong, Kah Fai; Kempen, Karolien; Thijs, Lore; Yasa, Evren; Van Humbeeck, Jan; Kruth, Jean-Pierre

    2012-01-01

    Selective Laser Melting (SLM) is an Additive Manufacturing (AM) technique that is able to process both metallic and ceramic materials in powder form. The main attraction of SLM is the ability to produce near fully dense functional parts with high geometrical complexity. Parts can be fabricated with features and designs conventional manufacturing methods cannot achieve. In this study, the feasibility of processing M2 High Speed Steel (HSS) with the SLM technique is investigated. The main focus...

  7. Service behaviour of high speed steel rolling rolls used in hot strip mills

    Work rolls used in hot strip mills may be able to carry out severe actions: very high thermal stresses and wear, along with mechanical stresses due to normal rolling loads, which develop in the presence of cracks, produced by the former actions. The microstructure and the mechanical behaviour (strength and toughness) of high speed steels, which recently have been introduced in this applications, were studied in this work in comparison with high chromium cast irons. (Author) 7 refs

  8. Methodology of high-speed steels design using the artificial intelligence tools

    W. Sitek

    2010-04-01

    Full Text Available Purpose: The main goal of the research carried out was developing the design methodology for the new high-speed steels with the required properties, including hardness and fracture toughness, as the main properties guaranteeing the high durability and quality of tools made from them. It was decided that hardness and fracture toughness KIc are the criteria used during the high-speed steels design.Design/methodology/approach: In case of hardness, the statistical and neural network models were developed making computation possible of the high-speed steel hardness based solely on the steel chemical composition and its heat treatment parameters, i.e., austenitizing- and tempering temperatures. In this case results of own work on the effect of alloy elements on the secondary hardness effect were used, as well as data contained in catalogues and pertinent standards regarding the high-speed steels. In the second case - high-speed steels fracture toughness, the neural network model was developed, making it possible to compute the KIc factor based on the steel chemical composition and its heat treatment parameters. The developed material models were used for designing the chemical compositions if the new high-speed steel, demonstrating the desired properties, i.e., hardness and fracture toughness. Methodology was developed to this end, employing the evolutionary algorithms, multicriteria optimisation of the high-speed steels chemical composition.Findings: Results of the research carried out confirmed the assumption that using the data from catalogues and from standards is possible, which - would supplement the set of data indispensable to develop the assumed model - improving in this way its adequacy and versatility.Practical implications: Solutions presented in the work, based on using the adequate material models may feature an interesting alternative in designing of the new materials with the required properties. The practical aspect has to be noted

  9. Structure and properties of FGM manufactured on the basis of HS6-5-2

    G. Matula

    2006-04-01

    Full Text Available Purpose: It has been demonstrated in the paper structure and properties of tool gradient materials manufactured by powder metallurgy on the basis of high speed-steel HS6-5-2 type.Design/methodology/approach: Light microscope, SEM, image analysis, microhardness tests, density examination.Findings: Basing on the investigations of the HS6-5-2 type high-speed steels reinforced with ceramics particles fabricated with Powder Metallurgy it was found that density of sintered samples depend on reinforced particles, temperatures and atmosphere of sintering. Increasing of sintering temperature increase the density of sintering samples. Moreover the sintering under N2-10%H2 atmosphere produce samples with higher quality than using argon atmosphere and prevent of surface oxidation during sintering.Practical implications: The Powder Metallurgy gives the possibility to manufacturing tools gradient materials on the basis of high speed-steel which characterised very high hardness on the surface.Originality/value: In the paper the manufacturing of tool gradient materials on basis of high speed-steel reinforced with hard ceramics particles carried out in order to improve the tool cutting properties.

  10. On the thermo-mechanical events during friction surfacing of high speed steels

    Bedford, G.M.; Vitanov, V.I.; Voutchkov, I.I.

    2001-01-01

    This paper is concerned with the friction surfacing of high-speed steels, BM2, BT15 and ASP30 onto plain carbon steel plate. The events that the matrix and carbides experience as the coating material pass from the coating rod to the substrate, in forming the coating, is described. The coating is observed to harden automatically within a few seconds of being deposited onto the cold substrate. This autohardening is observed to be an inherent feature of the friction surfacing process and the onl...

  11. A study of segregation mechanism in centrifugal cast high speed steel rolls

    Segregation influences the microstructure and performance of high speed steel (HSS) roll. The main reason why segregation occurs in centrifugal cast HSS roll is that atom clusters are formed in HSS melt and such atom clusters have different densities. The high-density atom clusters move to the outer periphery and the low-density atom clusters move to the inner periphery of the roll under centrifugal force. Changing the movement law of atom clusters in the centrifugal force field and increasing the solidification rate of HSS melt can lighten the segregation in HSS roll and improve its performance

  12. Effect of casting technology on microstructure and phases of high carbon high speed steel

    Zhang Tianming; Wang Qinjuan; Song Xuding

    2011-01-01

    The as-cast microstructures of high carbon high speed steels (HC-HSS) made by sand casting, centrifugal casting and electromagnetic centrifugal casting, respectively, were studied by using of optical microscopy (OM) and D/max2200pc X-ray diffraction. The results show that the microstructure of as-cast HC-HSS is dominated by alloy carbides (W2C, VC, Cr7C3), martensite and austenite. The centrifugal casting and electromagnetic centrifugal casting apparently improve the solidification structure ...

  13. High temperature oxidation behavior of high speed steel for hot rolls material

    Li Zhou; Fang Liu; Changsheng Liu; Dale Sun; Lisong Yao

    2005-01-01

    The oxidation characteristics of high speed steel (HSS) were studied at 500 to 800℃. The non-isothermal oxidation and isothermal oxidation (500, 575, 650, 725, 800℃) of HSS were investigated by thermo-gravimetric analysis (TGA). The microstructure, morphology and oxide scale thickness of the isothermal oxidation samples were analyzed by optical microscope (OM), electron probe micro analyzer (EPMA), X-ray diffraction spectrum (XRD) and scanning electron microscope (SEM). The results indicate that the oxidation rate of HSS is very slow at 500 to 650℃, increasing gradually at 650 to 750℃, and drastically at 750 to 800℃, because the phase transformation happens at about 750℃.

  14. High Temperature Oxidation Behavior of High Speed Steel for Roll in Water Vapor

    ZHOU Li; LIU Fang; LIU Chang-sheng; SUN Da-le

    2004-01-01

    The oxidation behavior of high speed steel (HSS) was researched by high temperature thermo balance at 500to 800℃ in water vapor. The morphology was observed by scanning electron microscope, the microstructure of oxide scale was analyzed by energy dispersive spectrometer and X-ray diffraction spectrum. The results indicate that the mass gain of HSS increases with oxidation temperature rising, the effect of oxidation temperature on the morphology is obvious, water vapor temperature only affects mass gain and affects hardly morphology of oxide scale at the same oxidation temperature. The relevant oxidation mechanisms are also discussed.

  15. Structure-phase transformations in surface layer of high speed steel during high current boron implantation

    High current ion ion implantation (HCII) of boron with energy of 20 keV, current density of 0.53 m A/cm2, dose of 2·1018 B/cm2 at temperature of 500 0C into AISI M2 high speed steel was carried out. The dominant process determining structure-phase state of steel during boron HCII was found to be radiation induced segregation. It leads to clusterization of boron in near-surface region (up to 0.6 μm), inhibition of borides formation processes (borides concentration doesn't exceed 14 %), preferable synthesis of Fe B boride being more rich with boron comparing to Fe2B

  16. Residual stress in a M3:2 PM high speed steel; effect of mechanical loading

    Højerslev, Christian; Odén, Magnus; Carstensen, Jesper V.;

    2001-01-01

    X-ray lattice strains were investigated in an AISI M3:2 PM high-speed steel in the as heat treated condition and after exposure to alternating mechanical load. The volume changes during heat treatment were monitored with dilatometry. Hardened and tempered AISI M3:2 steel consists of tempered lath...... martensite and the carbides M6C,V8C7 and M23C6. In the as heat treated condition the stress state is triaxial. The primary carbides M6C and V8C7 experience a compressive state of stress. Exposure to an alternating mechanical load, changes the states of stress of V8C7 and tempered martensite, but does not...

  17. The investigation of microstructures and properties of SWV9 high speed tool steel after laser melting

    The article presents the results of an investigation of changes in microstructure, hardness, phase and chemical composition, of the CO2 laser-melted high-speed tool steel namely SWV9. Formation of structure under rapid solidification condition is described. Microstructural and compositional analysis considered of optical, SEM, TEM, X-ray diffraction analysis and the sliding wear investigations. Microhardness was determined using a Hanemann microhardness tester. The microstructure formed under rapid solidification conditions after laser melting of SWV9 steel shows high chemical homogeneity and is extremely refined. Structure obtained in the surface layer after laser melting permitted to get high level of hardness (about 1200 HV65) and improved wear resistance. (author)

  18. Effect of nitrogen on the austenite cooling transformation kinetics of a high-speed steel

    The austenite cooling transformation kinetics of a semi-high-speed steel (HSS) with or without additional nitrogen was studied by means of DT1000 dilatometer. The stability and composition of the carbides have also been investigated using transmission electron microscopy and scanning electron microscopy. The results indicate that the addition of nitrogen can improve the hardening ability and bring down the M s temperature of the steel. The carbides in the semi-HSS with nitrogen addition contain more W and Mo elements and less Cr element. They exhibit higher stability. Quenching hardness of the semi-HSS with N is insensitive to the austenization temperature in the range from 1223 to 1423 K

  19. Effect of quenching temperature on structure and properties of centrifugal casting high speed steel roll

    Fu Hanguang

    2009-02-01

    Full Text Available The critical points and time-temperature-transformation (TTT curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study. The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel (HSS roll has been investigated using scanning electron microscopy (SEM, light optical microscopy (LOM and X-ray diffraction (XRD as well as using tensile, impact, and hardness tests. The results show that the HSS roll has excellent hardenability and its matrix structure can be transformed into the martensite after being quenched in the sodium silicate solution. The retained austenite in the quenching structure increases and the hardness decreases when the quenching temperature exceeds 1,040℃. The tensile strength and impact toughness of HSS roll increase once the quenching temperature is raised from 980℃ to 1,040℃. However, the tensile strength and impact toughness have no signifi cant change when the quenching temperature exceeds 1,040℃. The HSS roll quenched at 1,040℃ exhibits excellent comprehensive mechanical properties.

  20. Reduced activation ODS ferritic steel - recent development in high speed hot extrusion processing

    Oksiuta, Zbigniew [Faculty of Mechanical Engineering, Bialystok Technical University (Poland); Lewandowska, Malgorzata; Kurzydlowski, Krzysztof [Faculty of Materials Science and Engineering, Warsaw University of Technology (Poland); Baluc, Nadine [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, Villigen PSI (Switzerland)

    2010-05-15

    The paper presents the microstructure and mechanical properties of an oxide dispersion strengthened (ODS), reduced activation, ferritic steel, namely the Fe-14Cr-2W-0.3Ti-0.3Y{sub 2}O{sub 3} alloy, which was fabricated by hot isostatic pressing followed by high speed hydrostatic extrusion (HSHE) and heat treatment HT at 1050 C. Transmission electron microscopy (TEM) observations revealed significant differences in the grain size and dislocation density between the as-HIPped and as-HSHE materials. It was also found that the microstructure of the steel is stable after HT. The HSHE process improves significantly the tensile and Charpy impact properties of the as-HIPped steel. The ultimate tensile strength at room temperature increases from 950 up to 1350 MPa, while the upper shelf energy increases from 3.0 up to 6.0 J. However, the ductile-to-brittle transition temperature (DBTT) remains relatively high (about 75 C).These results indicate that HSHE is a promising method for achieving grain refinement and thus improving the mechanical properties of ODS ferritic steels. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  1. Comparative study of AISI M3:2 high speed steel produced through different techniques of manufacturing

    In this work AISI M3:2 high speed steels obtained through different techniques of manufacturing, submitted to the same heat treatment procedure were evaluated by measuring their mechanical properties of transverse rupture strength and hardness. Sinter 23 obtained by hot isostatic pressing (HIP), VWM3C obtained by the conventional route and a M3:2 high speed steel obtained by cold compaction of water atomized powders and vacuum sintered with and without the addition of a small quantity of carbon were evaluated after the same heat treatment procedure. The vacuum sintered M3:2 high speed steel can be an alternative to the more expensive high speed steel produced by hot isostatic pressing and with similar properties presented by the conventional one. The characterization of the vacuum sintered M3:2 high speed steel was performed by measuring the densities of the green compacts and after the sintering cycle. The sintering produced an acceptable microstructure and densities near to the theoretical. The transverse rupture strength was evaluated by means of three point bending tests and the hardness by means of Rockwell C and Vickers tests. The technique of scanning electronic microscopy (SEM) was used to evaluate the microstructure and to establish a relation with the property of transverse rupture strength. The structure was determined by means of X-ray diffraction (XRD) patterns and the retained austenite was detected to all the conditions of heat treatment. The main contribution of this work is to establish a relation between the microstructure and the mechanical property of transverse rupture strength and to evaluate the AISI M3:2 vacuum sintered high speed steel as an alternative to the similar commercial high speed steels. (author)

  2. Formation of gradient surface layers on high speed steel by laser surface alloying process

    M. Bonek

    2012-12-01

    Full Text Available Purpose: The purpose of this research paper is focused on the high speed steel HS6-5-3-8 surface layers improvement properties using HPDL laser. The paper present laser surface technologies, investigation of structure and properties of the high speed steel alloying with the WC, VC, TiC, SiC, Si3N4 and Al2O3 particles using high power diode laser HPDL.Design/methodology/approach: Investigation indicate the influence of the alloying elements on the structure and properties of the surface layer of investigated steel depending on the kind of alloying carbides, oxides, nitrides and power implemented laser (HPDL.Findings: Laser alloying of surface layer of investigated steel without introducing alloying additions into liquid molten metal pool, in the whole range of used laser power, causes size reduction of dendritic microstructure with the direction of crystallization consistent with the direction of heat carrying away from the zone of impact of laser beam. In the effect of laser alloying with powder of the WC, VC, TiC, SiC, Si3N4and Al2O3 particles occurs size reduction of microstructure as well as dispersion hardening through fused in but partially dissolved particles and consolidation through enrichment of surface layer in alloying additions coming from dissolving elements. Introduced particles of carbides, oxides, nitrides and in part remain undissolved, creating conglomerates being a result of fusion of undissolved powder grains into molten metal base. In effect of convection movements of material in the liquid state, conglomerates of carbides arrange themselves in the characteristic of swirl. Practical implications: Laser surface modification has the important cognitive significance and gives grounds to the practical employment of these technologies for forming the surfaces of new tools and regeneration of the used ones.Originality/value: The structural mechanism was determined of surface layers development, effect was studied of alloying

  3. Microstructure simulation of rapidly solidified ASP30 high-speed steel particles by gas atomization

    Ma, Jie; Wang, Bo; Yang, Zhi-liang; Wu, Guang-xin; Zhang, Jie-yu; Zhao, Shun-li

    2016-03-01

    In this study, the microstructure evolution of rapidly solidified ASP30 high-speed steel particles was predicted using a simulation method based on the cellular automaton-finite element (CAFE) model. The dendritic growth kinetics, in view of the characteristics of ASP30 steel, were calculated and combined with macro heat transfer calculations by user-defined functions (UDFs) to simulate the microstructure of gas-atomized particles. The relationship among particle diameter, undercooling, and the convection heat transfer coefficient was also investigated to provide cooling conditions for simulations. The simulated results indicated that a columnar grain microstructure was observed in small particles, whereas an equiaxed microstructure was observed in large particles. In addition, the morphologies and microstructures of gas-atomized ASP30 steel particles were also investigated experimentally using scanning electron microscopy (SEM). The experimental results showed that four major types of microstructures were formed: dendritic, equiaxed, mixed, and multi-droplet microstructures. The simulated results and the available experimental data are in good agreement.

  4. Fatigue Behavior of High Speed Steel Roll Materials for Hot Rolling by Laser Impacting

    ZHOU Li; SUN Da-le; LIU Chang-sheng; WU Qiong

    2006-01-01

    The fatigue behavior of high speed steel (HSS) roll materials for hot rolling was researched under water-cooling conditions by laser impacting. The microstructure of HSS sample and the morphologies of fatigue samples were observed by scanning electron microscope. The phase structure was detected by XRD. The morphology of situ oxide scale was observed by optical microscope, and the expansion coefficient was measured by TGA. The experiment results indicate that the cracks come into being at the carbide-matrix interface, but there are no cracks in the matrix after many times of laser impacting treatment, for the situ sample taken from the fractured roll surface, big carbides are more sensitive to the fatigue, and peel off prior to small ones. The relevant fatigue mechanisms are also discussed.

  5. Development of Focused Ion Beam technique for high speed steel 3D-SEM artefact fabrication

    Carli, Lorenzo; MacDonald, A. Nicole; De Chiffre, Leonardo;

    2009-01-01

    The work describes preliminary manufacture by grinding, followed by machining on a Focused Ion Beam (FIB), of a high speed steel step artefact for 3D-SEM calibration. The FIB is coupled with a SEM in the so called dual beam instrument. The milling capabilities of FIB were checked from a qualitative...... point of view, using the dual beam SEM imaging, and quantitatively using a reference stylus instrument, to establish traceability. A triangular section having a depth of about 10 μm was machined, where the 50 μm curvature radius due to grinding was reduced to about 2 μm by FIB milling...... as it was estimated using the dual beam SEM....

  6. SEM and TEM microstructural investigation of high-speed tool steel after laser melting

    Kac, S.; Kusinski, J

    2003-08-28

    The microstructure of a continuous CO{sub 2} laser-melted high-speed steel, namely M2, has been studied. The formation of the microstructure under rapid solidification conditions is described by means of scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. A very fine dendritic structure is characteristic for the microstructure formed under such rapid solidification conditions like laser melting. This structure generally consists of fine dendrites of austenite crossed by a very fine carbide network or the eutectic without the primary large carbides. The structure obtained in the surface layer after laser melting permits to get a high level of hardness and shows an improved wear resistance.

  7. SEM and TEM microstructural investigation of high-speed tool steel after laser melting

    The microstructure of a continuous CO2 laser-melted high-speed steel, namely M2, has been studied. The formation of the microstructure under rapid solidification conditions is described by means of scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. A very fine dendritic structure is characteristic for the microstructure formed under such rapid solidification conditions like laser melting. This structure generally consists of fine dendrites of austenite crossed by a very fine carbide network or the eutectic without the primary large carbides. The structure obtained in the surface layer after laser melting permits to get a high level of hardness and shows an improved wear resistance

  8. Critical shapes and arrangements of carbides in high-speed tool steel

    Antretter, T. [Montanuniv., Leoben (Austria). Christian Doppler Lab. for Micromechanics of Mater.; Fischer, F.D. [Institute of Mechanics, Montanuniversitat Leoben, Franz-Josef-Strasse 18, A-8700, Leoben (Austria)

    1997-09-15

    High-speed tool steel can be regarded as a particle reinforced composite consisting of carbides embedded in a martensitic matrix. The internal stress distribution in such a material shows a significant dependency on various parameters such as geometry, material and arrangement of the inclusions as well as external loading conditions. Recent theoretical results confirm the experimental observations that material failure is initiated by cleavage fracture of the carbides rather than matrix rupture. Given a constant volume-fraction of particles in the composite material a Weibull approach is employed to estimate the fracture probability of the carbides. Various inclusion shapes are examined for uniaxial loading conditions. The correlations between the probability of fracture of the inclusion and the parameters defining the geometry of the model will be demonstrated. Particular emphasis is put on the significance of the Weibull modulus m. (orig.) 17 refs.

  9. Tempering behavior of a semi-high speed steel containing nitrogen

    The decomposition behavior of martensite and precipitation characteristics of carbonitrides during the tempering process of a low-alloy high-speed steel (semi-HSS) containing nitrogen were investigated by means of transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometry and electron energy loss spectroscopy. The results shown the secondary hardening effect is reinforced with addition of nitrogen and the secondary hardening temperature range has expanded. The stability of retained austenite is also studied. When tempered in the temperature range of 425-525 deg. C, large quantities of fine-scale V-rich nitride precipitations distribute in the matrix homogeneously. A complex carbonitride phase can form when tempered at 550 deg. C

  10. Solidification microstructure of M2 high speed steel by different casting technologies

    Zhou Xuefeng

    2011-08-01

    Full Text Available The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies, namely iron mould casting and continuous casting. The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks, which were greatly refined in the ingot made by continuous casting process, compared with that by the iron mould casting process. M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods. In the ingot by iron mould casting, they have a plate-like morphology and grow anisotropically. However, in the ingot made by continuous casting, the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth. It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated, as a result, the carbides refined remarkably, compared with the case of plate-like carbides in the iron mould casting ingot.

  11. Study of the solidification of M2 high speed steel Laser Cladding coatings

    Candel, J. J.

    2013-10-01

    Full Text Available High speed steel laser cladding coatings are complex because cracks appear and the hardness is lower than expected. In this paper AISI M2 tool steel coatings on medium carbon AISI 1045 steel substrate have been manufactured and after Laser Cladding (LC processing it has been applied a tempering heat treatment to reduce the amount of retained austenite and to precipitate secondary carbides. The study of metallurgical transformations by Scanning Electron Microscopy (SEM and Electron Back Scattered Diffraction (EBSD shows that the microstructure is extremely fine and complex, with eutectic transformations and MC, M2C and M6C precipitation. Therefore, after the laser coating is necessary to use post-weld heat treatments.Los recubrimientos de acero rápido por Laser Cladding (LC son complejos porque aparecen fisuras y la dureza es menor a la esperada. En este trabajo se han fabricado recubrimientos de acero AISI M2 sobre acero al carbono AISI 1045 y tras el procesado por láser, se han revenido para reducir la cantidad de austenita retenida y precipitar carburos secundarios. El estudio de las transformaciones metalúrgicas con Microscopía Electrónica de Barrido (MEB y Difracción de Electrones Retrodispersados (EBSD muestra que la microestructura es extremadamente fina y compleja, presenta transformaciones eutécticas y precipitación de carburos MC, M2C y M6C. Por tanto, tras el recubrimiento por láser es necesario recurrir a tratamientos térmicos post-soldeo.

  12. The refinement of the surface layer of HS 7425 high speed tool steel by laser and electric arc plasma

    W. Bochnowski

    2008-10-01

    Full Text Available The paper present two different techniques: laser remelting surface and plasma remelting surface of the high speed steel HS 7425. Thestructure of the remelted layers were examined by means of SEM – microscopy. Measurement of microhardness in remelting zone usingVickers method. The remelting zone consist of dendritic cells and columnar crystals. Increase of hardness was observed in remelted zonein comparison to the substrate of the steel. The hardness in the remelted zone increases with the increasing cooling rate.

  13. HIGH SPEED END MILLING OF HARDENED AISI D3 COLD WORK TOOL STEEL WITH CBN CUTTING TOOL

    Aslan, E; CAMUŞCU, N.

    2010-01-01

    ABSTRACTIn this work, high speed end milling of AISI D3 cold-work tool steel hardened to 35 HRC and 62 HRC was investigated using CBN cutting tools. Cutting tool performance was studied with respect to tool life and surface finish of the workpiece. The effect of material hardness on the tool wear and surface roughness was also discussed.

  14. Computer simulation of the influence of the alloying elements on secondary hardness of the high-speed steels

    The paper presents the method of modelling of high-speed steels' (HSS) properties, being basing on chemical composition and heat treatment parameters, employing neural networks. An example of its application possibility the computer simulation was made of the influence of the particular alloying elements on hardness and obtained results are presented. (author)

  15. Microstructure of two centrifugal cast high speed steels for hot strip mills applications

    Highlights: → The structure of two HSS grades (Kosmos and Aurora) was characterized. → The effects of heat treatments on the structure were studied. → The Aurora grade presents secondary hardening due to the presence of very fine M2C carbide. → The hardness of the Aurora grade is not influenced by depth in the part. → The intrinsic hardness of MC carbides was measured by nanoindentation. -- Abstract: High speed steels (HSS) present excellent hardness, wear resistance and high-temperature properties. These mechanical properties are due to the presence of a great amount of hard carbides in the martensitic matrix. In the last 10 years, Japanese rollmakers have developed HSS grades and introduced them into hot strip mills. The Marichal Ketin society (Liege, Belgium) has developed two grades of HSS: Kosmos and Aurora. Both grades present interesting properties but Aurora shows overall better performance than Kosmos, mainly because of a better distribution of harder (MC and M2C) carbides in the martensitic matrix. Moreover, the hardness of the Aurora grade stays constant in depth and can be strongly improved by heat treatment, due to secondary hardening. The purpose of this work is to describe the microstructure and the mechanical properties of the Kosmos and Aurora grades by various techniques such as optical microscopy, scanning electron microscopy (SEM), and macrohardness measurements.

  16. Effect of casting technology on microstructure and phases of high carbon high speed steel

    Zhang Tianming

    2011-05-01

    Full Text Available The as-cast microstructures of high carbon high speed steels (HC-HSS made by sand casting, centrifugal casting and electromagnetic centrifugal casting, respectively, were studied by using of optical microscopy (OM and D/max2200pc X-ray diffraction. The results show that the microstructure of as-cast HC-HSS is dominated by alloy carbides (W2C, VC, Cr7C3, martensite and austenite. The centrifugal casting and electromagnetic centrifugal casting apparently improve the solidification structure of HC-HSS. With the increase of magnetic intensity (B, the volume fraction of austenite in the HC-HSS solidification structure increases significantly while the eutectic ledeburite decreases. Moreover, the secondary carbides precipitated from the austenite are finer with more homogeneous distribution in the electromagnetic centrifugal castings. It has also been found that the lath of eutectic carbide in ledeburite becomes finer and carbide phase spacing in eutectic ledeburite increases along with the higher magnetic field strength.

  17. On microstructure and performance of tempered high-boron high-speed steel roll

    Fu Hanguang

    2012-08-01

    Full Text Available Influences of the tempering temperature on the microstructure, mechanical property and wear resistance of High-Boron High Speed Steel (HBHSS roll materials were investigated by means of optical microscopy, scanning electron microscopy (SEM, X-ray diffraction, hardness measurement, impact tester, tensile tester and pin abrasion tester. The results show that the as-cast structure of HBHSS consists of a great amount of martensite and M2(B,C and a few retained austenites and M23(B,C6. After solution treated at 1,050 °C and followed by oil cooling, the amount of M23(B,C6 carbo-borides in quenched HBHSS increases obviously and the macrohardness of the quenched HBHSS is 66 HRC, which is very close to the 65.8 HRC of as-cast HBHSS. On the whole, the hardness of HBHSS alloy shows a trend of slight decrease with increasing tempering temperature when tempered below 500 °C. While when above 500 °C, the hardness increases slightly as the tempering temperature increases and reaches a peak at 525 °C and then decreases obviously. The impact toughness of HBHSS has a tendency to increase as the tempering temperature increases. Tempering can improve the tensile strength and elongation of HBHSS, but a higher tempering temperature causes a slight decrease in both tensile strength and elongation. Excellent wear resistance can be obtained by tempering at 500 to 550 °C.

  18. Machining tools in AISI M2 high-speed steel obtained by spray forming process

    The aim of the present work was the obtention of AISI M2 high-speed steel by spray forming technique and the material evaluation when used as machining tool. The obtained material was hot rolled at 50% and 72% reduction ratios, and from which it was manufactured inserts for machining tests. The performance of inserts made of the spray formed material was compared to inserts obtained from conventional and powder metallurgy (MP) processed materials. The spray formed material was chemical, physical, mechanical and microstructural characterised. For further characterisation, the materials were submitted to machining tests for performance evaluation under real work condition. The results of material characterisation highlight the potential of the spray forming technique, in the obtention of materials with good characteristics and properties. Under the current processing, hot rolling and heat treatments condition, the analysis of the results of the machining tests revealed a very similar behaviour among the tested materials. Proceeding a criterious analysis of the machining results tests, it was verified that the performance presented by the powder metallurgy material (MP) was slight superior, followed by conventional obtained material (MConv), which presented a insignificant advantage over the spray formed and hot rolled (72% reduction ratio) material. The worst result was encountered for the spray forming and hot rolled (50% reduction ratio) material that presented the highest wear values. (author)

  19. Joint strength in high speed friction stir spot welded DP 980 steel

    Saunders, Nathan; Miles, Michael; Hartman, Trent; Hovanski, Yuri; Hong, Sung Tae; Steel, Russell

    2014-05-01

    High speed friction stir spot welding was applied to 1.2 mm thick DP 980 steel sheets under different welding conditions, using PCBN tools. The range of vertical feed rates used during welding was 2.5 mm – 102 mm per minute, while the range of spindle speeds was 2500 – 6000 rpm. Extended testing was carried out for five different sets of welding conditions, until tool failure. These welding conditions resulted in vertical welding loads of 3.6 – 8.2 kN and lap shear tension failure loads of 8.9 – 11.1 kN. PCBN tools were shown, in the best case, to provide lap shear tension fracture loads at or above 9 kN for 900 spot welds, after which tool failure caused a rapid drop in joint strength. Joint strength was shown to be strongly correlated to bond area, which was measured from weld cross sections. Failure modes of the tested joints were a function of bond area and softening that occurred in the heat-affected zone.

  20. Solidification Microstructure of AISI M2 High Speed Steel Manufactured by the Horizontal Continuous Casting Process

    Zhou, X. F.; Fang, F.; Jiang, J. Q.

    2011-01-01

    In the present work, AISI M2 high speed steel is produced by the horizontal continuous casting process. The difference of solidification microstructure in ingots by mould casting and continuous casting has been examined by means of scanning electron microscope (SEM), electron back-scatter diffraction (EBSD), transmission electron microscope (TEM) and high resolution electron microscope (HREM). The results show that the as-cast structure consists of iron matrix and networks of M2C eutectic carbides, which are greatly refined in the continuous casting ingot compared to the case of ingot by mould casting. Meanwhile, the morphology of M2C eutectic carbides changes from the plate-like shape into the fibrous one. Micro-twining and stacking faults are observed in the plate-like M2C, whereas they are rarely identified in the fibrous M2C. Based on the characteristic of morphology and microstructure, it is expected that the plate-like M2C is a faceted phase while the fibrous M2C is a non-faceted phase.

  1. Effect of Alloying Additions on the Oxidation of High Speed Steels under Dry and Wet Conditions

    F.C. RIZZO; M.J.MONTEIRO; S.R.J.SAUNDERS

    2009-01-01

    An investigation has been carried out into the effects of chromium and vanadium content on the oxidation rate and on the adhesion of oxide scales grown on three different chemical compositions of high speed steels under dry and wet conditions. The oxidation tests were carried out in a thermobalance at 650 ℃ for up to 14.4 ks. The mass gain of the specimens increased with increasing contents of water vapour. Alloy composition had no effect on the oxidation rate in dry conditions. The "adhesion" of the oxide scale was determined using indentation with a Rockwell C diamond and the pull adhesion test to determine the interfacial toughness and the tensile strength of the oxide metal bond, respectively. Generally, the results of the investigation indicated that oxide adhesion was lowest for the specimens exposed to dry conditions, and that with increasing water vapour content, the scale was more adherent. Indentation test results showed that an increase in the Ⅴ concentration was deleterious to oxidc adhesion in both the dry and wet environments, whereas an increase in the Cr-content had little effect on adhesion.

  2. Phase Diagram Calculation and Analyze on Cast High-Boron High-Speed Steel

    Yang, Yong-wei; Fu, Han-guang; Lei, Yong-ping; Wang, Kai-ming; Zhu, Li-long; Jiang, Liang

    2016-02-01

    The equilibrium phases of high-boron high-speed steel whose compositions are 0-3.0% B, 0.2-0.8% C, 4.0-8.0% Cr, 2.0-4.0% Mo, 0.5-1.5% Al, 0.5-1.5% Si, 0-1.0% Mn, and 0.5-1.5% V were calculated and vertical section pseudo-binary phase diagrams were drawn by Thermo-Calc software. The phase transformation and carbides precipitation temperatures were measured by using differential scanning calorimetry. The type of carbides and matrix of the as-cast specimens were determined by using x-ray diffraction. Meanwhile, the shape and the number of carbides in the different specimens were detected by using optical microscope and scanning electron microscope. The influence of boron, carbon, aluminum, and chromium elements on equilibrium phase diagrams was discussed. The calculation results obtained from Thermo-Calc software are agreed with the ones from experiments. This work provides a practical method for engineers and researchers in related areas.

  3. Effects of heat treatment on structures and properties of high speed steel rolls

    Hanguang Fu; Jun Yang; Dening Zou; Jiandong Xing

    2004-01-01

    The effects of quenching temperature, cooling pattern, temper temperature and temper times on the structure and properties of high speed steel (HSS) rolls have been investigated. The results show that, when the quenching temperature is lower than 1050℃ the hardness of HSS increases with the quenching temperature increasing in oil cooling, but when the quenching temperature exceeds 1100℃ the hardness decreases. In the conditions of salt bath cooling and air cooling, the effect of quenching temperature on the hardness is similar to the above law, but the quenching temperature obtaining the highest hardness is higher than that in oil cooling. When the temper temperature below 350℃ the hardness of HSS has a little change, when above 475℃ the hardness will increase with the temper temperature increasing, and the highest hardness is obtained at 525℃. When the temper temperature continues to increase, the hardness decreases. Twice temper has little effect on the hardness, but three times temper decreases the hardness.HSS in air cooling has lower hardenability, oil cooling can easily produce crackle, and HSS quenching in salt bath has high hardenability and excellent wear resistance.

  4. Phase transformation study of a high speed steel powder by high temperature X-ray diffraction

    The combined utilization of an X-ray diffractometer and a high temperature chamber is used for the direct observation of phase transformations, changes in lattice imperfections, chemistry and the structure of the phases of a high speed steel powder. M6C-carbides are at first suppressed for the high cooling rates during atomization and only MC-carbides are detected at room temperature. The high amount of retained austenite of the origin powder is associated with interstitially dissolved carbon. During heating-up above 710 deg. C the formation of M6C-carbides occurs simultaneously with the transformation of austenite to a body centered cubic structure. Above 800 deg. C a significant decrease of the MC-carbides occurs; a direct transformation of the MC to M6C-carbides was not found. The formation and dissolving of carbides occurs only in an interaction with the austenite, martensite and bainite. Therefore the carbon content of the matrix influences the nature and course of transformations. After the whole heat treatment the mixture of phases gets nearer to an equilibrium

  5. RESEARCH OF INFLUENCE OF THE HIGH-SPEED THERMAL PROCESSING REGIMES ON STRUCTURE AND MECHANICAL PROPERTIES OF PIPE STEEL 32G2

    A. I. Gordienko

    2012-01-01

    Full Text Available Researches on influence of high-speed heating temperature, regimes of cooling and temperature of abatement on structure and mechanical properties of pipe steel 32G2 are carried out. Recommendations on the regimes of high-speed thermal processing of steel 32G2 which can be used at manufacturing of seamless pipes are given.

  6. Modification of AISI M2 high speed tool steels after laser surface melting under different operation conditions

    We applied a laser surface melting treatment to AISIM2 high-speed steel hardened and tempered- and studied the resulting surface characteristics (microstructure) and mechanical behavior (hardness and wear performance). The steel was treated using a Nd:YAG continuous-wave laser with different operation conditions. The influence of the laser processing parameters on the single tracks and on melted surface layer obtained by multipass system with 50% overlap were studied. The microstructure for all conditions is formed by MC- and M2C-type carbides, martensite and retained austenite; the quantities of this phase depends on the operations conditions. It has been determined that low levels of power density and high speed scanning of the beam leads to greater homogeneity in the microstructure with high hardness values and wear resistance. (Author) 26 refs.

  7. MATHEMATICAL FORMULATION OF PLASTIC CHARACTERISTICS OF WIRE OF STEEL 70 AT HIGH-SPEED WIRE DRAWING

    Yu. L. Bobarikin

    2011-01-01

    Full Text Available The carried out numerical experiments subject to initial and boundary conditions indicate that mathematical model of elastic-plastic characteristics of steel 90 can be used for numerical calculations of wire drawing routes for this grade of steel.

  8. A study on the crack control of a high-speed steel roll fabricated by a centrifugal casting technique

    The effects of roll materials, mould parameter, pouring parameter and cooling parameter on the crack of a high-speed steel (HSS) roll, which is manufactured by means of centrifugal casting, are investigated. The improvement of the HSS roll is effectively achieved through the addition of suitable amounts of potassium and rare earth (RE). The hot tearing force (i.e. the resistance to hot tearing) of the modified HSS roll is increased by 32.77% and reaches 158 N, while the line constriction (i.e. the solidification constriction of the HSS in unit distance) is decreased. In addition, the temperature field and stress field of the roll can be improved by adopting variable-speed centrifugal casting, variable-flux pouring and variable-speed solidification cooling techniques, which help to improve the filling and solidification of the molten steel and eliminate the cracks

  9. Carbides crystalline structure of AISI M2 high-speed steel

    The aim of this study was to identify the crystallographic structure of the extracted carbides of AISI M2 steel spray formed The structure determination of these carbides. The structure determination of these carbides is a very hard work. Since these structures were formed by atom migration it is not possible to reproduce them by a controlled process with a determined chemical composition. The solution of this problem is to obtain the carbide by chemical extraction from the steel. (Author)

  10. The Effects of Austenitizing Conditions on the Microstructure and Wear Resistance of a Centrifugally Cast High-Speed Steel Roll

    Kang, Minwoo; Lee, Young-Kook

    2016-04-01

    The influences of austenitizing conditions on the microstructure and wear resistance of a centrifugally cast high-speed steel roll were investigated through thermodynamic calculation, microstructural analysis, and high-temperature wear tests. When the austenitizing temperature was between 1323 K and 1423 K (1050 °C and 1150 °C), coarse eutectic M2C plates were decomposed into a mixture of MC and M6C particles. However, at 1473 K (1200 °C), the M2C plates were first replaced by both new austenite grains and MC particles without M6C particles, and then remaining M2C particles were dissolved during the growth of MC particles. The wear resistance of the HSS roll was improved with increasing austenitizing temperature up to 1473 K (1200 °C) because the coarse eutectic M2C plates, which are vulnerable to crack propagation, changed to disconnected hard M6C and MC particles.

  11. The Adhesion Improvement of Cubic Boron Nitride Film on High Speed Steel Substrate Implanted by Boron Element

    CAI Zhi-hai; ZHANG Ping; TAN Jun

    2005-01-01

    Cubic boron nitride(c-BN) films were deposited on W6Mo5Cr4V2 high speed steel(HSS) substrate implanted with boron ion by RF-magnetron sputtering. The films were analyzed by the bending beam method, scratch test, XPS and AFM. The experimental results show that the implantation of boron atom can reduce the in ternal stress and improve the adhesion strength of the films. The critical load of scratch test rises to 27.45 N, compared to 1.75 N of c-BN film on the unimplanted HSS. The AFM shows that the surface of the c-BN film on the implanted HSS is low in roughness and small in grain size. Then the composition of the boron implanted layer was analyzed by the XPS. And the influence of the boron implanted layer on the internal stress and adhesion strength of c-BN films were investigated.

  12. The Effects of Austenitizing Conditions on the Microstructure and Wear Resistance of a Centrifugally Cast High-Speed Steel Roll

    Kang, Minwoo; Lee, Young-Kook

    2016-07-01

    The influences of austenitizing conditions on the microstructure and wear resistance of a centrifugally cast high-speed steel roll were investigated through thermodynamic calculation, microstructural analysis, and high-temperature wear tests. When the austenitizing temperature was between 1323 K and 1423 K (1050 °C and 1150 °C), coarse eutectic M2C plates were decomposed into a mixture of MC and M6C particles. However, at 1473 K (1200 °C), the M2C plates were first replaced by both new austenite grains and MC particles without M6C particles, and then remaining M2C particles were dissolved during the growth of MC particles. The wear resistance of the HSS roll was improved with increasing austenitizing temperature up to 1473 K (1200 °C) because the coarse eutectic M2C plates, which are vulnerable to crack propagation, changed to disconnected hard M6C and MC particles.

  13. Analysis of rhodium-base intermetallic compound, white metal and high speed steel by ICP-AES

    The determination procedures of major component of intermetallic compound and alloys which were difficult to dissolve was investigated with ICP-AES. NdRhxBy as intermetallic compound was dissolved in aqua regia, and the residue was fused with NaHSO4 · H2O. RhAl as intermetallic compound was dissolved in hydrochloric acid after fusion with NaHSO4 · H2O. Nd, Rh, B, Al and Cu in these samples were determined with correction of spectral interference caused by Nd. White metal was dissolved in mixture of nitric acid and hydrochloric acid containing tartaric acid for prevention of hydrolysis of Sn and Sb in the sample. Pb, Sn, Sb and Cu as major element in it were determined. High speed steel was dissolved in mixture of sulfuric acid and phosphoric acid. Mo, V, Co, W and Cr as minor component were determined. Spectral interferences caused by Fe, V and Co were corrected. (author)

  14. Effect of Austenitizing Temperature on Microstructure and Mechanical Properties of Semi-High-Speed Steel Cold-Forged Rolls

    Wu, Qiong; Sun, Da-Le; Liu, Chang-Sheng

    2009-10-01

    The effect of austenitizing temperature on the microstructure and mechanical properties of semi-high-speed steel (S-HSS) cold-forged rolls was investigated. Low-temperature austenitizing below 1313 K induced carbide coarsening during subsequent tempering at 973 K due to the nucleation effect of undissolved M7C3. On the other hand, the heavy dissolution of M7C3 above 1353 K caused the fine carbide formation on lath and plate boundaries, which retarded the subgrain growth during tempering. The increase in strength with increasing austenitizing temperature was attributed to the fine carbide distribution and the high dislocation density. Furthermore, as the austenitizing temperature increased, the impact energy markedly reduced, due to the large prior austenite grain size and the high strength. Finally, based on the microstructure and mechanical properties, an optimal austenitizing temperature range between 1313 and 1333 K was determined.

  15. Influence of hot rolling and high speed hydrostatic extrusion on the microstructure and mechanical properties of RAF ODS steel

    Argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti oxide dispersion strengthened (ODS) ferritic steel powder was mechanically alloyed with 0.3Y2O3 (wt.%) nano-particles in attritor ball mill and consolidated by hot isostatic pressing (HIP) at 1150 deg. C under pressure of 200 MPa for 3 hrs. To improve mechanical properties of as HIPped ODS ingots the material was undergone further thermo-mechanical treatment (TMT), namely: hot rolling (HR) at 850 deg. C or high speed hot extrusion (HSHE) at 850 deg. C. After TMT both materials were annealed at 1050 deg. C for 1 h in vacuum. Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment exhibited elongated in a longitudinal direction grains with an average size of 75 μm. However, an equiaxed, smaller than 500 nm grains were also found in the microstructure of both materials. Different size and morphology of oxides particles were also observed. Bigger, about 150 nm Ti-Al-O particles were usually located at grain boundaries whereas Y-Ti-O nanoclusters of about 5 nm were uniformly distributed in ODS steel matrix. The Charpy impact tests revealed significantly better about 90% (5.8 J) upper shelf energy (USE) of material after HSHE but ductile to brittle transition temperature (DBTT) of both alloys was unsatisfactory. As-HR ODS steel has shown DBTT of about 55 deg. C whereas HSHE ODS steel has about 75 deg. C. This relatively high values of transition temperature were probably caused by oxides particles present at grain boundaries of the ODS alloys which decreased fracture properties of the ODS steels. High temperature tensile properties of both ODS alloys are found to be satisfactory in full range of the testing temperature from 23 up to 750 deg. C. However, about 15% better UTS and YS0.2 (1350 MPa and 1285 MPa, respectively) as well as ductility were measured in the case of the as-HSHE ODS steel. These results indicates that HSHE process of the ODS steel can be considered as more

  16. Weldability of Nb steel by the submerged arc process, using national consumables, at high speed

    A set of procedures was established for welding of Nb micro-alloyed steel by the submerged arc process, using national consumables, in order to simultaneously achieve a more economic welding and better mechanical properties. By a series of experiments involuing seven flux-wire combinations, and three different welding conditions, the properties of the weldments were evalvated by means of mechanical tests (tension, bending and impact). Analysis of results was based on chemical composition and microstructure of the weldments. The influence of the consumables on microstructure and chemical composition was verified by relating the properties with the several flux-wire combinations. The possibility of determining the parameters satisfying the requirements of economic welding with a few tests was verified. The influence of welding parameters on wire consumption, basicity, activity and flux consumption was also determined. Finaly, given the difficulties usually encountered when selecting submerged arc consumables, the possibility was shown of establishing a systematic approach towards that purpose. From all the analyses and observations conclusion was obtained that for some of the flux-wire combinations considered, the proposed objectives were achieved. (Author)

  17. New PACVD-hard material layers for wear protection of high-speed steel

    Bartsch, K.; Leonhardt, A. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany); Langer, U.; Kuenanz, K. [Technische Universitaet Dresden, Institut fuer Produktionstechnik, D-01062, Dresden (Germany)

    1997-10-01

    TiC/C, (Ti,Al)N and (Ti,Al)C layers have been deposited employing PACVD under dc-pulse discharge conditions and were investigated with respect to their composition and structure. The layer hardness can be varied in a large range by varying the Al content and the C content in the case of the TiC/C layers. By incorporation of C in TiC layers the friction coefficient can be decreased. Analogously to TiN layers, oxygen impurities cause a drastic hardness decrease in (Ti,Al)N layers. It was demonstrated that by multilayer deposition including TiN, TiCN and (Ti,Al)N with single layers of 100-300 nm thickness the layer stress decreases by about 50%, which results in an increase in layer adhesion. PACVD (Ti,Al)N and TiC/C layers yielded comparable or even better results than PVD layers in drilling 41Cr4 steel and the Al-alloy AlSi9Cu3. (orig.) 11 refs.

  18. Laser forming cutting once quenched high-speed tool steel (HSTS) disk-shaped milling cutter

    Ding, Zhihong; Liu, Yongzhen; Weng, Shiping

    1998-08-01

    Laser cutting technology has been applied to ordinary alloy steel circular sawblade, but it is very rarely used in quenched HSTS disk-shape milling-cutters due to the material particularity. In this paper, the authors systematically explain the advantages of this new technique, respecting the optimum design of HSTS disk-shape milling-cutter, the specific characteristics of laser forming cutting once for all, the technology testing, the analysis of structural performance of tooth and the small batch production for verifying. The article displays its advantages completely as follows: The design for a perfect tooth profile is not bound to the ordinary machining methods; The special laser technique does not lower the hardness on the tooth nose so that this process and needs no follow-up operational sequences, ensures the excellent dynamic-balance performance and operation properties, and prolongs the tools' service time; The new technique also has advantages of high efficiency and good economics. Therefore, this special laser cutting method, an integration of intensified heat-treatment and laser forming cutting once for all technology, will be regarded as a reform in HSTS tools Manufacturing field.

  19. Chip formation and surface integrity in high-speed machining of hardened steel

    Kishawy, Hossam Eldeen A.

    Increasing demands for high production rates as well as cost reduction have emphasized the potential for the industrial application of hard turning technology during the past few years. Machining instead of grinding hardened steel components reduces the machining sequence, the machining time, and the specific cutting energy. Hard turning Is characterized by the generation of high temperatures, the formation of saw toothed chips, and the high ratio of thrust to tangential cutting force components. Although a large volume of literature exists on hard turning, the change in machined surface physical properties represents a major challenge. Thus, a better understanding of the cutting mechanism in hard turning is still required. In particular, the chip formation process and the surface integrity of the machined surface are important issues which require further research. In this thesis, a mechanistic model for saw toothed chip formation is presented. This model is based on the concept of crack initiation on the free surface of the workpiece. The model presented explains the mechanism of chip formation. In addition, experimental investigation is conducted in order to study the chip morphology. The effect of process parameters, including edge preparation and tool wear on the chip morphology, is studied using Scanning Electron Microscopy (SEM). The dynamics of chip formation are also investigated. The surface integrity of the machined parts is also investigated. This investigation focusses on residual stresses as well as surface and sub-surface deformation. A three dimensional thermo-elasto-plastic finite element model is developed to predict the machining residual stresses. The effect of flank wear is introduced during the analysis. Although residual stresses have complicated origins and are introduced by many factors, in this model only the thermal and mechanical factors are considered. The finite element analysis demonstrates the significant effect of the heat generated

  20. Ion-nitriding of the AISI M2 high speed tool steel and comparison of its mechanical properties with nitrided steels

    Cimen, O.; Alnipak, B. [Univ. of Istanbul, Avcilar, Istanbul (Turkey)

    1995-12-31

    In the past it was shown that plasma diffusion treatment of steels has several advantages over conventional processes such as gas or salt bath nitriding and nitrocarburizing. Plasma diffusion treatment allows close control of the process so that surface layers with defined microstructures and properties can be obtained. The amount of {gamma}{prime} and {epsilon} phase present can be easily controlled. In this paper, variation of surfaces hardness properties of AISI M2 high speed tool speed after ion nitriding treatments were investigated. The mechanical and electro-chemical advantages of the ion nitrided structures were compared with the other methods.

  1. Influence of hot rolling and high speed hydrostatic extrusion on the microstructure and mechanical properties of an ODS RAF steel

    An argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti (wt.%) reduced activation ferritic (RAF) steel powder was mechanically alloyed with 0.3wt.% Y2O3 nano-particles in an attritor ball mill and consolidated by hot isostatic pressing at 1150 oC under a pressure of 200 MPa for 3 h. In the aim to improve its mechanical properties the ODS steel was then submitted to a thermo-mechanical treatment (TMT): hot rolling (HR) at 850 deg. C or high speed hydrostatic extrusion (HSHE) at 900 deg. C, followed by heat treatment (HT). Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment revealed the presence of elongated grains in the longitudinal direction, with an average width of 8 μm and an average length of 75 μm, and equiaxed grains, a few microns in diameter, in the transverse direction. Two populations of oxide particles were observed by TEM: large Ti-Al-O particles, up to 250 nm in diameter, usually located at the grain boundaries and small Y-Ti-O nanoclusters, about 2.5 nm in diameter, uniformly distributed in the matrix. Charpy impact tests revealed that the HSHE material exhibits a larger upper shelf energy (5.8 J) than the HR material (2.9 J). The ductile-to-brittle transition temperature of both alloys is relatively high, in the range of 55-72 deg. C. Tensile mechanical properties of both ODS alloys were found satisfactory over the full range of investigated temperatures (23-750 deg. C). The HSHE material exhibits better tensile strength and ductility than the HR material. These results indicate that HSHE can be considered as a promising TMT method for improving the mechanical properties of ODS RAF steels.

  2. Effects of Alloying Elements on Microstructure, Hardness, Wear Resistance, and Surface Roughness of Centrifugally Cast High-Speed Steel Rolls

    Ha, Dae Jin; Sung, Hyo Kyung; Park, Joon Wook; Lee, Sunghak

    2009-11-01

    A study was made of the effects of carbon, tungsten, molybdenum, and vanadium on the wear resistance and surface roughness of five high-speed steel (HSS) rolls manufactured by the centrifugal casting method. High-temperature wear tests were conducted on these rolls to experimentally simulate the wear process during hot rolling. The HSS rolls contained a large amount (up to 25 vol pct) of carbides, such as MC, M2C, and M7C3 carbides formed in the tempered martensite matrix. The matrix consisted mainly of tempered lath martensite when the carbon content in the matrix was small, and contained a considerable amount of tempered plate martensite when the carbon content increased. The high-temperature wear test results indicated that the wear resistance and surface roughness of the rolls were enhanced when the amount of hard MC carbides formed inside solidification cells increased and their distribution was homogeneous. The best wear resistance and surface roughness were obtained from a roll in which a large amount of MC carbides were homogeneously distributed in the tempered lath martensite matrix. The appropriate contents of the carbon equivalent, tungsten equivalent, and vanadium were 2.0 to 2.3, 9 to 10, and 5 to 6 pct, respectively.

  3. The effect of high-energy electron-beam irradiation on microstructural modification of a high-speed steel roll

    The purpose of this study is to investigate the microstructural modification in a high-speed steel (HSS) roll irradiated with an accelerated high-energy electron beam. The HSS roll samples were irradiated at the beam travel speeds of 2.5 to 25 mm/s using an electron accelerator (1.4 MeV). The microstructure was examined with a scanning electron microscope (SEM) capable of in situ fracture testing and simultaneous measurement of the apparent fracture toughness. Irradiation changed the matrix phase from tempered martensite to a mixture of retained austenite and martensite. Coarse primary carbides were partially or completely dissolved, depending on the heat input. Irradiation greatly improved the fracture properties because of the presence of retained austenite, which could retard crack propagation, although hardness was decreased. Occasional interior quench cracks were found in the heat-affected region. Appropriate processing methods, such as pre- or postirradiation, were suggested. A heat transfer analysis of the irradiated surface layer was also carried out to elucidate the influence of the irradiation parameters on the microstructure

  4. Microstructural characterization of WC-TiC-Co cutting tools during high-speed machining of P20 mold steel

    The wear behavior of tungsten carbide (WC)-TiC-Co cutting tools during cutting P20 tool steel was investigated. Orthogonal cutting tests were performed on a CNC lathe using five speeds, namely, 60, 120, 240, 380 and 600 m/min. Wear, as the width of the wear land, was monitored at five time intervals. Wear characterization of the rake and the flank surfaces as well as the collected chips was performed using scanning electron microscopy (SEM), backscattered electron imaging and energy-dispersive X-ray analysis (EDX). Microhardness of collected chips was also performed to monitor strain hardening effects during cutting. Two dominant wear mechanisms were identified: at high speed (380-600 m/min), wear was found to occur by a melt wear mechanism; at low speed (60-120 m/min), adhesion (built-up edge) followed by delamination was found to be the cause of wear damage. It was also found that deformation in the chips occurred by localized shear deformation

  5. Optimization of heat treatment technique of high-vanadium high-speed steel based on back-propagation neural networks

    This paper is dedicated to the application of artificial neural networks in optimizing heat treatment technique of high-vanadium high-speed steel (HVHSS), including predictions of retained austenite content (A), hardness (H) and wear resistance (ε) according to quenching and tempering temperatures (T1, T2). Multilayer back-propagation (BP) networks are created and trained using comprehensive datasets tested by the authors. And very good performances of the neural networks are achieved. The prediction results show residual austenite content decreases with decreasing quenching temperature or increasing tempering temperature. The maximum value of relative wear resistance occurs at quenching of 1000-1050 deg. C and tempering of 530-560 deg. C, corresponding to the peak value of hardness and retained austenite content of about 20-40 vol%. The prediction values have sufficiently mined the basic domain knowledge of heat treatment process of HVHSS. A convenient and powerful method of optimizing heat treatment technique has been provided by the authors

  6. Weight-based synthesized standards preparation for correction-free calibration in X-ray fluorescence determination of tungsten in high-speed steel

    This paper suggests a correction-free calibration method in wavelength dispersive X-ray fluorescence analysis in order to determine tungsten as a major alloyed element in high-speed steels accurately. Matrix effects on fluorescent X-ray intensity of tungsten Lα line were minimized by borate fusion, and the total amount of tungsten in the glassy matrix could be quantified. Glass bead specimens were prepared with 10 to 12 mg of the steel sample and 4.0 g of lithium tetraborate as a flux agent. Without untraceable X-ray intensity correction, a linear calibration curve was obtained by measuring synthesized calibration standards prepared by using standard solutions. As compared with fundamental parameter calculations, the present method gave more accurate results of tungsten in certified reference materials of high-speed steel. (author)

  7. The material performance of HSS (high speed steel) tools and its relation with chemical composition and carbide distribution

    Darmawan, B.; Kusman, M.; Hamdani, R. A.

    2016-04-01

    The study aims to compare the performance of two types of material HSS (High Speed Steel) are widely used. It also will be the chemical composition and distribution of carbide particles therein. Two types of HSS are available in the market: HSS from Germany (Bohler) and HSS from China. This research employed the pure experimental design. It consists of two stages. The first, aims to test/operate lathe machines to determine the lifetime and performance of tools based on specified wear criteria. The second, characterization of microstructure using SEM-EDS was conducted. Firstly, grinding of toolss was done so that the toolss could be used for cutting metal in the turning process. Grinding processes of the two types of toolss were done at the same geometry, that is side rake angle (12°-18°), angle of keenness (60°-68°), and side relief angle (10°-12°). Likewise, machining parameters were set in the same machining conditions. Based on the results of the tests, it is found that to reach 0.2 mm wear point, toolss made of HSS from Germany needed 24 minutes, while toolss made of HSS from China needed 8 minutes. Next, microstructure tests using SEM/EDS were done. The results of the SEM tests indicate that the carbide particles of HSS from Germany were more evenly distributed than the carbide particles of HSS from China. Carbide compounds identified in HSS from China were Cr23C6 and Fe4Mo2C. Oxide impurity of Al2O3 was also found in the material. On the other hand, in HSS from Germany, no impurity and other carbide compounds were identified, except Cr23C6 and Fe4Mo2C, also Fe4W2C, and VC or V4C3.

  8. Cleavage dynamic propagation analysis in a nuclear reactor pressure vessel steel using a high-speed camera

    Initiation stage of cracks is considered as a key issue, but more and more component integrity analyses investigate the crack propagation and arrest possibility. This study deals with physical mechanisms of cleavage crack propagation and numerical computations related to brittle fracture. Dynamic effects, involved in unstable cleavage crack propagation, have to be taken into account to properly depict brittle crack propagation, arrest and possible propagation re-initiation events. Experiments were carried out on thin CT specimens made of 16MND5 PWR vessel steel at five temperatures (-150 degrees C, -125 degrees C, -100 degrees C, -75 degrees C, -50 degrees C). In addition to standard crack gages, an innovative experimental technique has been used to determine crack propagation. By the means of developments on the experimental protocol (improvements of isolation and airtightness of the thermal chamber, optimization of the experimental protocol to eliminate ice in the thermal chamber and in order to have a good acquisition quality), use of a high speed framing camera was made possible to measure crack propagation on a CT mirror polished surface. This optical device, combined with this optimized experimental process, has allowed the study of straight and branching crack paths with high accuracy. The framing camera (520 000 fps up to 1 100 000 fps) has allowed to have a very accurate estimation of crack speed even up to 1000 m.s-1 and also to detect some phases of crack branching during propagation and phases of arrest-re-initiation. Numerical computations, based on X-FEM and combining a local non linear dynamic approach with a RKR type fracture stress criterion, have been performed to depict experimental crack behavior. This paper describes this innovative experimentation and the interpretation by FE calculations and SEM observations associated with quantitative 3D optical microscopy. (authors)

  9. High speed door assembly

    Shapiro, C.

    1991-12-31

    This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  10. Development of Centrifugal Cast High Speed Steel Roll with High Wear Resistance for Pre-Finishing Stands of a Hot Rod-Wire Mill

    JIANG Zhi-qiang; FENG Xi-lan; FU Han-guang; SHA Quan-you

    2004-01-01

    The present study aims at developing high speed steel ( HSS ) as roll materials to replace traditional roll materials such as the alloy cast iron and powder metallurgical (PM) hard alloy, because lowcost alley cast iron rolls have poor wear resistance and the cost of high-quality PM hard alloy rolls is too high to be accepted by some users. By means of a centrifugal casting method, HSS rolls with excellent wear resistance have been developed. Its hardness is 65 ~ 67HRC, and its variation is smaller than 2HRC ; its impact toughness excels 15J/cm2. Using pre-finishing stands of a high-speed hot wire-rod rolling mill, the wear raze of HSS rolls per one thousand ton of steel is 0. 25mm. However, the manufacturing burden of HSS rolls is obviously lower than that of PM hard alloy rolls; it is only 30% of that of PM hard alloy rolls.

  11. High speed tool steel cut off dies made using powder metallurgy techniques; Fabricacion de matrices de corte con aceros rapidos para herramientas mediante metalurgia de polvos

    Talacchia, S.; Amador, J.; Urcola, J. [Escuela Superior de Ingenieros, Universidad de Navarra, San Sebastian (Spain)

    1996-06-01

    The present work summarises the results obtained by compacting water atomized powders of T42 modifed carbon and vanadium, M3/2 and M2 high speed steels. The powders were compacted under complex forms (cut off dies) and sintered under a 90 N{sub 2}-9 H{sub 2}-1 CH{sub 4} industrial atmosphere. Heat treatments in different severity media were performed. hardness of 1,100 HV can be obtained in the case of T42 modified steel. Also, the shrinking of the sintered specimens was study. (Author) 6 refs.

  12. Phase transformations during heat treatment of W-Mo-V 11-2-2 type high-speed steels with increased contents of Si and Nb or Ti

    Dobrzanski, L.A.; Zarychta, A.; Ligarski, M. [Division of Tool Materials and Computer Techniques in Metal Service, Silesian Technical University, Gliwice (Poland)

    1995-12-31

    The paper presents results of investigations in W-Mo-V 11-2-2 high-speed steels with a part of vanadium substituted with niobium or titanium. The optimum combinations of 0.5%Nb or 0.3%Ti with 1.6%V gave maximum hardness of 65.5-66 HRC after tempering at 570-540{sup o}C, respectively. In all steels covered by the study secondary hardening was due chiefly to precipitation of fine M{sub 4}C{sub 3} carbides in martensite and martensitic transformation of retained austenite into {alpha} phase. (author). 14 refs, 3 tabs.

  13. Phase transformations during heat treatment of W-Mo-V 11-2-2 type high-speed steels with increased contents of Si and Nb or Ti

    The paper presents results of investigations in W-Mo-V 11-2-2 high-speed steels with a part of vanadium substituted with niobium or titanium. The optimum combinations of 0.5%Nb or 0.3%Ti with 1.6%V gave maximum hardness of 65.5-66 HRC after tempering at 570-540oC, respectively. In all steels covered by the study secondary hardening was due chiefly to precipitation of fine M4C3 carbides in martensite and martensitic transformation of retained austenite into α phase. (author)

  14. Development of high-speed tool steel roll and its application to rolling mill; Koseino haisuroru no kaihatsu to atsuen bun`ya eno tekiyorei

    Takigawa, H.; Tanaka, T.; Otomo, S.; Hashimoto, M. [Nippon Steel Corp., Tokyo (Japan)

    1997-07-30

    Technical development in the field of steel rolling in recent years has been carried out from the viewpoints of improving the quality of steel products, improving the productivity, and reducing the manufacturing costs. With this technical development, a need for the highly reliable rolling mill roll with a high performance and a long life has extensively grown. Thereupon, the authors have developed a rolling mill roll called the high-speed tool steel roll. This roll was originally designed for the finishing stands of hot strip mill, and it demonstrated a high performance when using. As the result, the quality of rolled steel products has been improved and such restrictions on rolling operation resulted from the mill rolls have been sharply eased. On the basis of these successful results, the said roll has been also extensively applied in other fields of material rolling. This paper introduces the development of this high-speed tool steel roll and some examples of its application, together with results obtained. 5 refs., 15 figs., 2 tabs.

  15. Finite Element Modelling of the effect of tool rake angle on tool temperature and cutting force during high speed machining of AISI 4340 steel

    Sulaiman, S.; Roshan, A.; Ariffin, M. K. A.

    2013-12-01

    In this paper, a Finite Element Method (FEM) based on the ABAQUS explicit software which involves Johnson-Cook material model was used to simulate cutting force and tool temperature during high speed machining (HSM) of AISI 4340 steel. In this simulation work, a tool rake angle ranging from 0° to 20° and a range of cutting speeds between 300 to 550 m/min was investigated. The purpose of this simulation analysis was to find optimum tool rake angle where cutting force is smallest as well as tool temperature is lowest during high speed machining. It was found that cutting forces to have a decreasing trend as rake angle increased to positive direction. The optimum rake angle observed between 10° and 18° due to decrease of cutting force as 20% for all simulated cutting speeds. In addition, increasing cutting tool rake angle over its optimum value had negative influence on tool's performance and led to an increase in cutting temperature. The results give a better understanding and recognition of the cutting tool design for high speed machining processes.

  16. Finite Element Modelling of the effect of tool rake angle on tool temperature and cutting force during high speed machining of AISI 4340 steel

    In this paper, a Finite Element Method (FEM) based on the ABAQUS explicit software which involves Johnson-Cook material model was used to simulate cutting force and tool temperature during high speed machining (HSM) of AISI 4340 steel. In this simulation work, a tool rake angle ranging from 0° to 20° and a range of cutting speeds between 300 to 550 m/min was investigated. The purpose of this simulation analysis was to find optimum tool rake angle where cutting force is smallest as well as tool temperature is lowest during high speed machining. It was found that cutting forces to have a decreasing trend as rake angle increased to positive direction. The optimum rake angle observed between 10° and 18° due to decrease of cutting force as 20% for all simulated cutting speeds. In addition, increasing cutting tool rake angle over its optimum value had negative influence on tool's performance and led to an increase in cutting temperature. The results give a better understanding and recognition of the cutting tool design for high speed machining processes

  17. Effect of nitrogen on the stabilization of austenite in a tungsten-molybdenum high-speed steel

    A study was made of the tendency of steels R6M5 and R6Am5 to austenite stabilization after subzero treatment and high-temperature tempering in hot-rolled bars. Data indicate that in steel R6AM5 during quenching there is almost instantaneous austenite stabilization. The data was derived from a study of phase composition (exposure from a microsection in DRON-2.0 equipment in iron K /SUB alpha/ radiation), microstructure, and hardness. The authors conclude that in view of serious difficulties in metallurgical and tool production, steel R6AM5 should be supplied only at the request of the customer

  18. Performance evaluation of reactive direct current unbalanced magnetron sputter deposited nanostructured TiN coated high-speed steel drill bits

    Harish C Barshilia; K S Rajam

    2007-12-01

    The stainless steels, in general, are considered to be difficult-to-machine materials. In order to machine these materials the surface of the tool is generally coated with physical vapour deposition (PVD) hard coatings such as titanium nitride (TiN), titanium aluminum nitride (TiAlN), etc. The adhesion is of vital importance for the performance of tools coated with PVD coatings. Proper surface treatments (in situ and ex situ) are required to achieve highly adherent PVD coatings on tools. We have deposited nanostructured TiN coatings on high-speed steel (HSS) drill bits and mild steel substrates using an indigenously built semi-industrial fourcathode reactive direct current (d.c.) unbalanced magnetron sputtering system. Various treatments have been given to the substrates for improved adhesion of the TiN coatings. The process parameters have been optimized to achieve highly adherent thick good quality TiN coatings. These coatings have been characterized using X-ray diffraction, nanoindentation and atomic force microscopy techniques. The performance of the coated HSS drill bits is evaluated by drilling a 13 mm thick 304 stainless steel plate under wet conditions. The results show significant improvement in the performance of the TiN coated HSS drill bits.

  19. Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

    XIAO Ji-ming; LI Yan; WU Yu-sheng; BAI Li-jing; LI Ze-rong

    2004-01-01

    As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.

  20. Evolution mechanisms of MgO·Al2O3 inclusions by cerium in spring steel used in fasteners of high-speed railway

    The effect of rare earth metal addition on the non-metallic inclusions in spring steel used in fastener of high speed railway was investigated by metallographic examination; SEM-EDS and component analysis, aiming at deform those harmful inclusions to improve service life of spring steel. MgO·Al2O3 inclusions were found in present experimental steel, which is also confirmed by the stability diagram of MgO/MgO·Al2O3/Al2O3 from thermodynamic consideration. After Ce addition, the evolution process of Al2O3·MgO inclusions was determined through the surface and line scanning. The effects of time and Ce content on the evolution of Al2O3·MgO inclusions were examined. It was indicated that Al2O3·MgO inclusions were wrapped by rare earth inclusions to form a ring like shape Ce-riched band around the inclusion, which would be useful to improve fatigue and corrosion resistance of spring steel. It was found that diffusion of Ce3+, Al3+ and Mg2+ in inclusions core and intermediate layer would be the limited step during evolutions of inclusions. (author)

  1. Análisis experimental del torneado de alta velocidad del acero AISI 1045 // Experimental analysis of high speed turning of AISI 1045 steel gears

    Luís Wilfredo Hernández‐González

    2012-01-01

    Full Text Available El objetivo de este trabajo es el estudio experimental de la evolución del desgaste del flanco de dosinsertos de carburo recubiertos y un cermet, durante el torneado en seco del acero AISI 1045 con 500 y600 m/min de velocidad de corte. Los resultados fueron comparados utilizando el análisis de varianza y deregresión. La investigación mostró un efecto significativo de la velocidad de corte y del tiempo demaquinado en el desgaste del flanco. El mejor desempeño fue para el carburo recubierto con tres capas,mientras que a elevada velocidad de corte el carburo con dos capas sufrió el mayor desgaste, lo cual sedebe a que cuando pierde sus recubrimientos el substrato del inserto queda desprotegido y el desgastecrece rápidamente por la extremas condiciones del mecanizado por alta velocidad. Además, se planteanrecomendaciones del tiempo de maquinado de los insertos dadas las condiciones de elaboración por altavelocidad.Palabras claves: torneado de alta velocidad, desgaste del flanco, acero AISI 1045, estudio experimental.__________________________________________________________________________AbstractThis work deals with the experimental study of the flank wear evolution of two coating carbide inserts and acermet insert during the dry turning of AISI 1045 steel with 500 and 600 m/min cutting speed. The resultswere compared using the variance and regression analysis. The investigation showed a significant effectof cutting speed and machining time on the flank wear in high speed machining. The three coating layersinsert showed the best performance while the two layers insert had the worst behaviour of the cutting toolwear at high cutting speed, this is because once the coating film is peeled off, the substrate of the insertbecomes uncovered and the wear grows rapidly due to the extreme machining conditions for high speed.Besides, the machining time recommendations of inserts for the cutting conditions at high speed areexposed.Key words: high

  2. Comparative study of AISI M3:2 high speed steel produced through different techniques of manufacturing; Estudo comparativo de acos rapidos AISI M3:2 produzidos por diferentes processos de fabricacao

    Araujo Filho, Oscar Olimpio de

    2006-07-01

    In this work AISI M3:2 high speed steels obtained through different techniques of manufacturing, submitted to the same heat treatment procedure were evaluated by measuring their mechanical properties of transverse rupture strength and hardness. Sinter 23 obtained by hot isostatic pressing (HIP), VWM3C obtained by the conventional route and a M3:2 high speed steel obtained by cold compaction of water atomized powders and vacuum sintered with and without the addition of a small quantity of carbon were evaluated after the same heat treatment procedure. The vacuum sintered M3:2 high speed steel can be an alternative to the more expensive high speed steel produced by hot isostatic pressing and with similar properties presented by the conventional one. The characterization of the vacuum sintered M3:2 high speed steel was performed by measuring the densities of the green compacts and after the sintering cycle. The sintering produced an acceptable microstructure and densities near to the theoretical. The transverse rupture strength was evaluated by means of three point bending tests and the hardness by means of Rockwell C and Vickers tests. The technique of scanning electronic microscopy (SEM) was used to evaluate the microstructure and to establish a relation with the property of transverse rupture strength. The structure was determined by means of X-ray diffraction (XRD) patterns and the retained austenite was detected to all the conditions of heat treatment. The main contribution of this work is to establish a relation between the microstructure and the mechanical property of transverse rupture strength and to evaluate the AISI M3:2 vacuum sintered high speed steel as an alternative to the similar commercial high speed steels. (author)

  3. World record in high speed laser surface microstructuring of polymer and steel using direct laser interference patterning

    Lang, Valentin; Roch, Teja; Lasagni, Andrés. F.

    2016-03-01

    Periodic surfaces structures with micrometer or submicrometer resolution produced on the surface of components can be used to improve their mechanical, biological or optical properties. In particular, these surfaces can control the tribological performance of parts, for instance in the automotive industry. In the last years, substantial efforts have been made to develop new technologies capable to produce functionalized surfaces. One of these technologies is the Direct Laser Interference Patterning (DLIP) technology, which permits to combine high fabrication speed with high resolution even in the sub-micrometer range. In DLIP, a laser beam is split into two or more coherent beams which are guided to interfere on the work piece surface. This causes modulated laser intensities over the component's surface, enabling the direct fabrication of a periodic pattern based on selective laser ablation or melting. Depending on the angle between the laser beams and the wavelength of the laser, the pattern's spatial period can be perfectly controlled. In this study, we introduce new modular DLIP optical heads, developed at the Fraunhofer IWS and the Technische Universität Dresden for high-speed surface laser patterning of polymers and metals. For the first time it is shown that effective patterning speeds of up to 0.90 m2/min and 0.36 m2/min are possible on polymer and metals, respectively. Line- and dot-like surface architectures with spatial periods between 7 μm and 22 μm are shown.

  4. Full Scale Tests and Structural Evaluation of Soil-Steel Flexible Culverts for High-Speed Railways

    Andersson, Andreas; Sundquist, Håkan; Karoumi, Raid

    2012-01-01

    In this paper, results from full-scale tests on a corrugated soil-steel flexible culvert for railway traffic are presented. The bridge was instrumented with strain gauges, accelerometers and displacement gauges, measuring the response from passing trains. The aim of the measurement campaign was to gain knowledge of the dynamic behaviour due to train induced vibrations, both of the bridge structure and the overlying railway embankment. From the measured data, the load distribution and soil-sti...

  5. Evaluation of material microstructure changes in high speed tool steel by the non-collinear wave mixing technique with MST(magnetostrictive transducer)

    Choi, Jeongseok; Lee, Dong Jin; Cho, Younho

    2015-03-01

    Evaluation of material microstructure changes plays an important role in predicting material failure. Both destructive and nondestructive testings can be used to evaluate the variation of material microstructure. Destructive methods are used to directly verify the changes of material via microstructure picture in a vigorous manner while nonlinear ultrasonic NDE can render a promising tool for the cases. In this study, the MST driven non-collinear wave mixing technique is implemented to evaluate the material microstructure changes in high speed tool steel. The resonant wave is used to analyze the acoustic nonlinearity which is influenced by microstructure changes with various austenitizing temperature effects. Correlation microstructure change between the acoustic nonlinearity and material microstructure is accomplished to explore the feasibility of the non-collinear mixing technique.

  6. 关于高速钢若干问题的回顾与讨论%A Review and Discussion on Several Topics of High Speed Steels

    雷仲眉; 水洪

    2001-01-01

    Several questions on high speed steels which are still considered unsolved, such as ‘balanced carbon’,secondary hardening, transformation of retained austenite, and fish-scale fracture have been reviewed briefly. The authors have offered their own ideas on these topics, and thoughts for further research have been suggested authors' point of view.%对高速钢中合金元素与碳的关系、二次硬化、残留奥氏体转变、萘状断口等几个据认为尚无最后结论的研究课题,进行了简要的回顾。表明了作者的观点,并对进一步研究提出了自己的思路和建议。

  7. Comparative study of the interface composition of TiN and TiCN hard coatings on high speed steel substrates obtained by arc discharge

    Roman, E. (Lab. de Fisica de Superficies, Inst. de Ciencia de Materiales, CSIC, Madrid (Spain)); Segovia, J.L. de (Lab. de Fisica de Superficies, Inst. de Ciencia de Materiales, CSIC, Madrid (Spain)); Alberdi, A. (TEKNIKER, Asociacion de Investigacion Tecnologica, Eibar (Spain)); Calvo, J. (TEKNIKER, Asociacion de Investigacion Tecnologica, Eibar (Spain)); Laucirica, J. (TEKNIKER, Asociacion de Investigacion Tecnologica, Eibar (Spain))

    1993-05-15

    In this paper the composition of the interface of TiN and TiCN hard coatings deposited onto high speed steel substrates obtained by the arc discharge technique is studied using Auger electron spectroscopy at two different substrate temperatures, 520 K and 720 K. The low temperature (520 K) TiN coating developed an oxygen phase at the interface, producing a weak adherence of 40 N, while the high temperature coatings (720 K) had a less intense oxygen phase, giving a greater adherence to the substrate of 60 N. TiCN coatings at 520 K are characterized by a low oxygen intensity at the interface. However, their adherence of 50 N is lower than the value of 60 N for the high temperature TiN coatings and is independent of the substrate temperature. (orig.)

  8. Influence of hot rolling and high speed hot extrusion process on the microstructure and properties of R and A ODS ferritic steel

    Full text: Argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti oxide dispersion strengthened (ODS) ferritic steel powder was mechanically alloyed with 0.3Y2O3 (wt.%) nano-particles in attritor ball mill and consolidated by hot isostatic pressing (HIP) at 1150 deg. C under pressure of 200 MPa for 3 hrs. To improve mechanical properties of as HIPped ODS ingots the material was undergone further thermo-mechanical treatment (TMT), namely: hot rolling (HR) at 850 oC or high speed hot extrusion (HSHE) at 850 deg. C. After TMT both materials were annealed at 1050 deg. C for 1 h in vacuum. Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment exhibited elongated in a longitudinal direction grains with an average size of 75 μm. However, an equiaxed, smaller than 500 nm grains were also found in the microstructure of both materials. Different size and morphology of oxides particles were also observed. Bigger, about 150 nm Ti-Al-O particles were usually located at grain boundaries whereas Y-Ti-O nanoclusters of about 5 nm were uniformly distributed in ODS steel matrix. The Charpy impact tests revealed significantly better about 90% (5.8 J) upper shelf energy (USE) of material after HSHE but ductile to brittle transition temperature (DBTT) of both alloys was unsatisfactory. As-HR ODS steel has shown DBTT of about 55 deg. C whereas HSHE ODS steel has about 75 deg. C. This relatively high values of transition temperature were probably caused by oxides particles present at grain boundaries of the ODS alloys which decreased fracture properties of the ODS steels. High temperature tensile properties of both ODS alloys are found to be satisfactory in full range of the testing temperature from 23 up to 750 deg. C. However, about 15% better UTS and YS0.2 (1350 MPa and 1285 MPa, respectively) as well as ductility were measured in the case of the as-HSHE ODS steel. These results indicates that HSHE process of the ODS steel can be considered as

  9. 高速钢刀具复合涂层的研究现状%Research Status of Composite Coating for High Speed Steel Cutting Tools

    孙凯; 赵琳; 付拴拴

    2012-01-01

    为了满足刀具苛刻的工况条件,利用不同涂层材料的性能优点,在刀具表面形成多元多层复合涂层具有重大的意义.复合涂层技术具有抗磨损、抗高温氧化腐蚀、隔热、扩大涂层制品使用范围以及延长使用寿命等功能,已被各国列为机加工刀具发展的主要方向.简要叙述了高速钢刀具硬质复合涂层技术的发展和研究现状.%In order to meet harsh working conditions of catting tools, forming a multi-element and multi-layer composite coating on tool surface by using the performance benefits of different coating materials has a great significance. Composite coating, with functions of anti-wear, high temperature oxidation corrosion resistance and heat insulation, can expand the application scope and extend the service life of the coated products, so has been regarded as the main developing direction by various countries. The development and research status of hard composite coating technology for high speed steel cutting tools is briefly described.

  10. Termite high-speed steels

    Zhiguts, Yu.; Lazar, V; Talabirchuk, V.

    2015-01-01

    У результаті проведених теоретичних та експериментальних робіт встановлена можливість синтезу інструментальних швидкорізальних сталей металотермією. Виявлено вплив металотермічного методу синтезу на особливості мікроструктури і фазового складу термітних швидкорізальних сталей. Встановлені для синтезованих термітних аналогів промислових марок швидкорізальних сталей Р18л, Р12л, Р9л, Р6М3л, Р9К5л, Р10К5Ф5л механічні та технологічні властивості, а саме теплостійкість, відносна шліфовність, період...

  11. Novel experimental methods for investigating high speed friction of titanium-aluminum-vanadium/tool steel interface and dynamic failure of extrinsically toughened DRA composites

    Irfan, Mohammad Abdulaziz

    Dynamic deformation, flow, and failure are integral parts of all dynamic processes in materials. Invariably, dynamic failure also involves the relative sliding of one component of the material over the other. Advances in elucidation of these failure mechanisms under high loading rates has been of great interest to scientists working in this area. The need to develop new dynamic mechanical property tests for materials under well characterized and controllable loading conditions has always been a challenge to experimentalists. The current study focuses on the development of two experimental methods to study some aspects of dynamic material response. The first part focuses on the development of a single stage gas gun facility for investigating high-speed metal to metal interfacial friction with applications to high speed machining. During the course of this investigation a gas gun was designed and built capable of accelerating projectiles upto velocities of 1 km/s. Using this gas gun pressure-shear plate impact friction experiments were conducted to simulate conditions similar to high speed machining at the tool-workpiece interface. The impacting plates were fabricated from materials representing the tribo-pair of interest. Accurate measurements of the interfacial tractions, i.e. the normal pressure and the frictional stress at the tribo-pair interface, and the interfacial slip velocity could be made by employing laser interferometry. Normal pressures of the order of 1-2 MPa were generated and slipping velocities of the order of 50 m/s were obtained. In order to illustrate the structure of the constitutive law governing friction, the study included experimental investigation of frictional response to step changes in normal pressure and interfacial shear stress. The results of these experiments indicate that sliding resistance for Ti6Al4V/CH steel interface is much lower than measured under quasi-static sliding conditions. Also the temperature at the interface strongly

  12. High speed data acquisition

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab

  13. High speed data acquisition

    Cooper, P.S.

    1997-07-01

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab.

  14. High-Speed Photography

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) copyright 1998 Society of Photo-Optical Instrumentation Engineers

  15. High-Speed Photography

    Paisley, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Schelev, M.Y. [General Physics Institute, Moscow (Russia)

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  16. High Speed Economy

    Vadim Dumitrascu; Roxana Arabela Dumitrascu

    2013-01-01

    The use of knowledge in business opens vast possibilities for the spectacular intensification of the rhythms of the processes of economic value creation. High speeds are a fundamental feature of the knowledge economy. The sources of high speeds in business are certain economic, technological and commercial processes with the nature of some positive feedbacks. What generates it is the organization of knowledge in the form of networks. The organizations competitiveness is marked by the ability ...

  17. Effect of high magnetic field on carbide precipitation in W{sub 6}Mo{sub 5}Cr{sub 4}V{sub 3} high-speed steel during low-temperature tempering

    Wu, Yan [Northeastern Univ., Shenyang (China). Research Inst.; Li, Hui-Hui; Zhang, Zhi-Wei; Tong, Lu; Zhao, Xiang [Northeastern Univ., Shenyang (China). Key Lab. for Anisotropy and Texture of Materials (Ministry of Education)

    2016-04-15

    The effect of a high magnetic field on carbide precipitation in W{sub 6}Mo{sub 5}Cr{sub 4}V{sub 3} high-speed steel during low-temperature tempering was investigated. The applied high magnetic field promoted the precipitation of M{sub 6}C-type carbides at boundaries and in the grain interior, but maximum spheroidization and refinement occurred for those carbides precipitated at boundaries. Compared with M{sub 6}C-type carbides, the effect of high magnetic field on the precipitation behavior of MC-type carbides is much weaker. The high magnetic field hindered M{sub 2}C-type carbide precipitation by affecting the Gibbs free energy and increased the microhardness of W{sub 6}Mo{sub 5}Cr{sub 4}V{sub 3} high-speed steel at low tempering temperature.

  18. THE EFFECT OF NITROGEN GAS FLOW RATE ON THE PROPERTIES OF TiN-COATED HIGH-SPEED STEEL (HSS) USING CATHODIC ARC EVAPORATION PHYSICAL VAPOR DEPOSITION (PVD) TECHNIQUE

    ALI MUBARAK; ESAH BINTI HAMZAH; MOHD RADZI HJ. MOHD TOFF; ABDUL HAKIM BIN HASHIM

    2005-01-01

    Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride (TiN) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation techniq...

  19. Numerical Simulation and Process Optimization of Cryogenic Treatment of High Speed Steel Tap%高速钢丝锥深冷处理过程数值模拟与工艺优化

    孙绍泉; 张淳; 彭宁涛; 周雨先; 黄腾辉

    2015-01-01

    以材料为W9Mo3Cr4V、型号为 M24的高速钢丝锥来进行深冷处理过程的数值模拟与工艺优化。通过ANSYS的热分析模块(Transient Thermal)和流体分析模块(Flunet),对高速钢丝锥分别在浸泡深冷、匀速深冷和逐级深冷三种深冷处理工艺条件下的深冷处理过程进行数值模拟,并通过模拟结果进行比较分析,结果表明逐级深冷处理是最为理想的深冷处理工艺。%This article is to do the numerical simulation and process optimization of cryogenic treatment of M24 high speed steel tap , The material of high speed steel is W9Mo3Cr4V .Using the Transient Thermal module and Flunet module in ANSYS to do numerical simulation of high speed steel tap by three kinds of cryogenic treatment process ,which are soaking cryogenic treatment ,uniform speed cryogenic treatment and cryogenic treatment step by step .After analyzed the result of the simulation ,the conclusion is that cryogenic treatment step by step is the best solution of cryogenic treatment .

  20. 粉末冶金高速钢在汽车零件——气门座圈中的应用%P/M high-speed steel application in automotive componentsvalve seat inserts

    Rossi J.L.Salgado L.; Jesus Filho E.S.; Jesus E.R.B.; Ambrozio Filho F.; Santos J.C.2; Colosio M.A.

    2011-01-01

    This work presents aspects related to high-speed steels for valve seat inserts application. Two types of materials were evaluated ,one made on purpose high speed steel M3/2 mixed with iron powder and niobium carbide and another valve seat insert made of Fe-Co alloy, for comparison. The microstructure of the made on purpose valve seat insert was evaluated by scanning electron microscopy. The physical and mechanical properties of the high-speed steels studied are presented in terms of densification,hardness,radial mechanical strength and machining.%这篇文章介绍了关于高速钢用于气门座圈的情况.评定了两种材料:一种是研发的高速钢M3/2粉、Fe粉及NbC的混合粉制造的材料;一种是为了比较,由Fe-Co合金制造的气门座圈.用SEM对研制的气门座圈的显微组织进行了鉴定.对研发的高速钢的物理-力学性能将分别介绍密度、硬度、径向压溃强度及切削加工性.

  1. High speed photography

    Slemc, Tadej

    2010-01-01

    The main purpose of photography is to capture a moment in time and transfer the captured information onto the photographic paper. High speed photography is a photography technique in which parts of a very fast phenomenon are being captured. A phenomenon, which usually happens too fast to be captured by the human eye. An example of such is contact of a water drop with another surface. A person is capable to register the contact, but it is only by means of the high speed photography that one is...

  2. High Speed Network Sampling

    2005-01-01

    Abstract Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

  3. High speed network sampling

    2010-01-01

    Abstract Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

  4. EFFECT OF Nb ON THE MICROSTRUCTURE AND PROPERTIES OF SPRAY FORMED M3 HIGH SPEED STEEL%Nb对喷射成形M3型高速钢组织和性能的影响

    于一鹏; 黄进峰; 崔华; 蔡元华; 张济山

    2012-01-01

    为了利用NbC的高硬度和高热稳定性,并避免其在凝固过程中的过分长大,采用喷射成形快速凝固技术制备了M3型高速钢和以Nb代V的M3型高速钢.利用SEM,EDX和XRD等方法研究了Nb对喷射成形M3型高速钢沉积态组织的影响;利用SRV高温摩擦磨损试验机和三维白光干涉表面形貌仪研究了Nb对喷射成形M3型高速钢摩擦磨损性能的影响.结果表明,用等原子分数的Nb替代V,可大幅增加沉积态中一次MC型碳化物,减少一次M2C型碳化物,同时由于喷射成形高冷速的作用,使得MC碳化物尺寸减小,分布更弥散;这些MC型碳化物的存在是M3型高速钢的抗磨粒磨损性能提高的主要原因,但其对抗氧化性能并无贡献,在高载荷时抗氧化剥落磨损能力增加不明显;Nb对提高M3高速钢回火稳定性也有明显的作用.%Spray forming with a short process chains has been proven to be a powerful tool for the production of high-alloyed materials. Niobium, as a strong former for the carbide, will mainly form primary MC carbides, such as NbC, which can be formed via the reaction between Nb and C atoms at the beginning of solidification, and it can act as the inoculants and refine the cast structure of steel which can mainly form primary MC carbides. M3 high speed steel with or without Nb addition were prepared via spray forming. The effect of Nb on the microstructure of spray formed M3 high speed steel was investigated by SEM, EDX and XRD methods; the friction performances of these two steels were studied by SRV high temperature tribometer and 3D white-light interfering profilometer. The results show that the amount of primary MC carbides can increase sharply while the reduction of the amount of primary M2C due to the substitution of 2% Nb for 1% V (mass fraction) in M3 high speed steel. For the high cooling rate during the spray forming, the primary MC carbides can be refined and dispersed. Large number of primary MC carbides

  5. 强流脉冲电子束W18Cr4V高速钢表面处理%Surface treatment of W18Cr4V high speed steel irradiated by high current pulsed electron beam

    赵晖; 易赟; 陈燕; 朱其柱

    2011-01-01

    The surface of W 18Cr4 high speed steel (HSS)was irradiated by high current pulsed electron beam (HCPEB). The surface morphology, structure, elemental composition and the microhardness of the HSS before and after HCPEB irradiation were analyzed by using scanning electron microscope( SEM), X-ray diffraction( XRD), EDS and ultramicro load microhardness tester. The results show that HCPEB irradiation treatment makes the high speed steel surface appear crater, tiny holes, which lead to the undulating morphology, and the surface structure consists of tempered martensite changed into very fine austenite. The increasing C element in melted layer makes the austenite more stable. Due to the changing of high speed steel surface temperature and stress, the microhardness is significantly increased in a depth range of up to 300 μm,and the maximum hardness is 30% more than that of the substrate.%利用solo-强流脉冲电子束(HCPEB)装置对W18Cr4V高速钢进行表面辐照处理.通过扫描电子显微镜(SEM)、X射线衍射仪(XRD)、EDS能谱仪、超微载荷显微硬度计研究了该钢HCPEB处理后的表面形貌、表层组织结构、元素成分、显微硬度的变化.结果表明,HCPEB辐照处理使该钢表面出现火山口状熔坑、微小孔洞引起的波动起伏形貌,表层组织由回火马氏体变为极细奥氏体,熔化层碳元素含量的提高,增加了奥氏体常温稳定性.由于HCPEB辐照处理高速钢表层温度场及应力场的变化,试样在距表面以下300μm范围内出现显微硬度提高,最高硬度比基体提高约30%.

  6. Tribological behaviors of spot-textured TiN coatings on M2 high-speed steel under boundary lubricated conditions

    Guangneng Dong; Meng Hua; Jian Li; Hing-Yin Ma; Youbai Xie

    2007-01-01

    The effect of sliding duration on the tribological behaviors of spot patterned coatings was investigated. Two patterns based on physical vapor deposition (PVD) TiN coatings were used, such as, in-lined (IN) and staggered (ST) spots. The tribological behaviors were evaluated by using a Cameron-Plint wear test rig. The M2 steel discs deposited TiN coatings with IN and ST patterns slid against the ASSAB 17 tool steel pins at a speed of 0.23 m/s, in Shell Tellus T32 lubricant and were loaded with 900 N. The testing results on disc specimens with two types of PVD TiN spot patterns, all coated with a bias voltage of- 180 V and slid for 4, 8 and 11 h respectively,were presented. The results revealed that the in-lined coatings possessed relatively better wear behaviors than the staggered pattern coatings. Mechanisms for such superiority and for the cause of peeling were discussed. A relevant design approach was suggested for the application of such patterned coatings.

  7. Multi-functional Ksub{Ic}-test specimen for the assessment of different tool- and high-speed-steel properties: Večfunkcijski Kspodaj{Ic}-preizkušanec za določanje različnih lastnosti orodnih in hitroreznih jekel:

    LESKOVŠEK, Vojteh; Podgornik, Bojan

    2013-01-01

    Depending on the differences in the balanced alloy composition and steel processing technology, the properties of tool and high-speed steel, like temper resistance, hot yield strength, ductility and toughness, thermal fatigue and shock resistance, as well as wear resistance can differ considerably among the same type of steel. A high hot-yield strength, a high temper resistance and a good ductility tend to result in a high resistance to thermal fatigue, while a resistance to mechanical and th...

  8. Experimental investigation of cutting tool performance in high speed cutting of hardened X210 Cr12 cold-work tool steel (62 HRC)

    This study explored the performance and wear behaviour of different cutting tools in end milling of X210 Cr12 cold-work tool steel hardened to 62 HRC. The purpose of the experiments reported in this paper is to investigate the wear of TiCN coated tungsten carbide, TiCN + TiAlN coated tungsten carbide, TiAlN coated cermet, mixed ceramic with Al2O3 + TiCN and cubic boron nitride (CBN) tools. Tool performance evaluation was based on the surface finish and tool flank wear. Tool flank wear was studied carefully through JSM 5600 (30 kW) scanning electron microscope. Surface roughness values were measured by Mitutoyo Metusurf 310 equipment. CBN tool exhibited the best cutting performance in terms of both flank wear and surface finish. The highest volume of metal removal was obtained with CBN tool

  9. Experimental investigation of cutting tool performance in high speed cutting of hardened X210 Cr12 cold-work tool steel (62 HRC)

    Aslan, E

    2005-02-15

    This study explored the performance and wear behaviour of different cutting tools in end milling of X210 Cr12 cold-work tool steel hardened to 62 HRC. The purpose of the experiments reported in this paper is to investigate the wear of TiCN coated tungsten carbide, TiCN + TiAlN coated tungsten carbide, TiAlN coated cermet, mixed ceramic with Al{sub 2}O{sub 3} + TiCN and cubic boron nitride (CBN) tools. Tool performance evaluation was based on the surface finish and tool flank wear. Tool flank wear was studied carefully through JSM 5600 (30 kW) scanning electron microscope. Surface roughness values were measured by Mitutoyo Metusurf 310 equipment. CBN tool exhibited the best cutting performance in terms of both flank wear and surface finish. The highest volume of metal removal was obtained with CBN tool.

  10. Performance evaluation of high speed compressors for high speed multipliers

    Nirlakalla Ravi

    2011-01-01

    Full Text Available This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP. This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25°C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP and Energy Delay Product (EDP of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.

  11. Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

    Jamaliah Idris; Chukwuekezie Christian; Eyu Gaius

    2013-01-01

    Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC) and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis par...

  12. Machining tools in AISI M2 high-speed steel obtained by spray forming process; Ferramentas de usinagem em aco rapido AISI M2 obtido por conformacao por 'spray'

    Jesus, Edilson Rosa Barbosa de. E-mail: erbjesus@usp.br

    2004-07-01

    The aim of the present work was the obtention of AISI M2 high-speed steel by spray forming technique and the material evaluation when used as machining tool. The obtained material was hot rolled at 50% and 72% reduction ratios, and from which it was manufactured inserts for machining tests. The performance of inserts made of the spray formed material was compared to inserts obtained from conventional and powder metallurgy (MP) processed materials. The spray formed material was chemical, physical, mechanical and microstructural characterised. For further characterisation, the materials were submitted to machining tests for performance evaluation under real work condition. The results of material characterisation highlight the potential of the spray forming technique, in the obtention of materials with good characteristics and properties. Under the current processing, hot rolling and heat treatments condition, the analysis of the results of the machining tests revealed a very similar behaviour among the tested materials. Proceeding a criterious analysis of the machining results tests, it was verified that the performance presented by the powder metallurgy material (MP) was slight superior, followed by conventional obtained material (MConv), which presented a insignificant advantage over the spray formed and hot rolled (72% reduction ratio) material. The worst result was encountered for the spray forming and hot rolled (50% reduction ratio) material that presented the highest wear values. (author)

  13. High-Speed Electrochemical Imaging.

    Momotenko, Dmitry; Byers, Joshua C; McKelvey, Kim; Kang, Minkyung; Unwin, Patrick R

    2015-09-22

    The design, development, and application of high-speed scanning electrochemical probe microscopy is reported. The approach allows the acquisition of a series of high-resolution images (typically 1000 pixels μm(-2)) at rates approaching 4 seconds per frame, while collecting up to 8000 image pixels per second, about 1000 times faster than typical imaging speeds used up to now. The focus is on scanning electrochemical cell microscopy (SECCM), but the principles and practicalities are applicable to many electrochemical imaging methods. The versatility of the high-speed scan concept is demonstrated at a variety of substrates, including imaging the electroactivity of a patterned self-assembled monolayer on gold, visualization of chemical reactions occurring at single wall carbon nanotubes, and probing nanoscale electrocatalysts for water splitting. These studies provide movies of spatial variations of electrochemical fluxes as a function of potential and a platform for the further development of high speed scanning with other electrochemical imaging techniques. PMID:26267455

  14. High-speed photonics interconnects

    Chrostowski, Lukas

    2013-01-01

    Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed

  15. High-speed pulse techniques

    Coekin, J A

    1975-01-01

    High-Speed Pulse Techniques covers the many aspects of technique in digital electronics and encompass some of the more fundamental factors that apply to all digital systems. The book describes the nature of pulse signals and their deliberate or inadvertent processing in networks, transmission lines and transformers, and then examines the characteristics and transient performance of semiconductor devices and integrated circuits. Some of the problems associated with the assembly of these into viable systems operating at ultra high speed are also looked at. The book examines the transients and w

  16. MICROSTRUCTURES AND PROPERTIES OF SPRAY FORMED Nb-CONTAINING M3 HIGH SPEED STEEL%喷射成形含铌M3型高速钢组织与性能研究

    王和斌; 侯陇刚; 张金祥; 卢林; 于一鹏; 崔华; 张济山

    2014-01-01

    采用喷射成形快速凝固技术制备了M3型高速钢和以Nb代V的M3型高速钢.利用SEM(EDS),XRD,OM,TEM,HRTEM研究了Nb对M3型高速钢组织的影响和其组织演变.结果表明,喷射成形消除了宏观偏析,细化了组织,以Nb代V,可在共晶反应前析出MC型碳化物,使其球形化、均匀分布,由于消耗大量C,共晶M2C碳化物数量减少,促使更多W和Mo固溶进基体.均匀分布的高热稳定性含Nb-MC型碳化物能阻碍奥氏体化过程中晶粒长大,但难以固溶,使得回火过程中主要析出与基体共格的M2C型碳化物.喷射成形含Nb钢硬度和弯曲强度高于ASP23钢,大量硬质MC碳化物易于产生应力集中,使其韧性稍低于ASP23.%The billets of M3 high speed steel (HSS) with or without niobium addition were prepared via spray forming and compared with traditional cast steels with same composition,followed by hot forged and heat treated.The corresponding microstructure evolutions of steels induced by niobium have been investigated using SEM with EDS,XRD,OM,TEM and HRTEM.The results show that finer and uniformly-distributed grains without macrosegregation appear in the as-deposited HSS that are different to the as-cast HSS,1% (mass fraction) niobium addition can promote the formation of primary MC-type carbides before onset of eutectic reaction,which can make the MC particles refined and evenly distributed.Niobium mainly contribute to the primary MC-type carbides by consuming carbon,the eutectic reaction is suppressed and the quantity of M2C eutectic carbides decrease,leading to more W and Mo atoms dissolve into matrix.Compared to spray formed M3 HSS,the niobium alloying M3 HSS possesses higher stability during austenitization,induced by the high stabilization of Nb-containing MC carbides,which can pin the grain boundaries and keep the grain size of primary austenite below that of spray formed M3 HSS.The quenched hardness of niobium-containing steel is remarkably higher,while the

  17. High-speed OTDM switching

    Jepsen, Kim Stokholm; Mikkelsen, Benny; Clausen, Anders;

    1998-01-01

    Optical TDM (OTDM) continues to be of interest both for point-point transmission and as a networking technology for both LANs and long-distance fibre transmission. Recent research has demonstrated enabling techniques for OTDM networks at high speeds. In conclusion, OTDM is emerging as an attractive...

  18. FABRICATION AND MECHANICAL PROPERTIES OF CENTRIFUGAL CAST HIGH SPEED STEEL ROLLER UNDER ELECTROMAGNETIC FIELD%电磁场下离心复合制备高速钢轧辊和力学性能

    李桂荣; 王宏明; 申国庆; 邵黎军; 步小平; 许晓静

    2013-01-01

    Pulse electromagnetic field is imposed during the centrifugal casting high speed steel to solve the segregation of elements and carbide. The main components of elements in high speed steel are designed as 1.5% - 2.5% C, 4.0 - 6.0% V, 4.0% - 6.0% W, 1.5% - 4.5% Mo, 2.0% - 4.0% Cr and 0.04% - 0. 18% Zr. The frequencies of pulse electromagnetic fields were set at 1, 2,4,6,8 and 10Hz levels separately. The corresponding magnetic induced intensities of mould center were 0.2 - 5T. The actual elemental components were analyzed u-sing Atomic Emission Spectrometer. During data processing parameter of variance was used to characterize the fluctuation and segregation of elements and carbides. After heat treatment of quenching and tempering several mechanical properties of materials were tested. The results show that the fluctuation and segregation have been inhibited after using pulse electromagnetic filed. The comprehensive mechanical properties are enhanced obviously, which include hardness, tensile strength, bending strength and impact toughness. The average increase amplification is a-bout 10% compared to that without using pulse electromagnetic field.%本文提出在离心铸造过程中施加脉冲电磁场,目的在于改善传统离心铸造容易造成元素和碳化物偏析的问题.高速钢中主要元素的设计含量为:1.5%~2.5%C,4.0~6.0%V,4.0%~6.0%W,1.5%~4.5% Mo,2.0%~4.0% Cr和0.04% ~0.18% Zr.对脉冲电磁场主要参数进行调控和优化,脉冲磁场频率分别设定为1、2、4、6、8、10Hz六个水平,对应铸型中心磁场的峰值强度范围为0.2 ~5T,经淬火和回火热处理后进行轧辊中元素含量和力学性能测试,并用方差来表征轧辊工作层径向方向元素含量波动及偏析情况.研究结果显示,在离心铸造过程中施加电磁场后,能起到抑制合金元素和碳化物偏析的作用,与未加磁场相比,硬度、抗拉强度、抗弯强度和冲击韧性

  19. The Effect of Nitrogen Gas Flow Rate on the Properties of TiN-COATED High-Speed Steel (hss) Using Cathodic Arc Evaporation Physical Vapor Deposition (pvd) Technique

    Mubarak, Ali; Hamzah, Esah Binti; Mohd Toff, Mohd Radzi Hj.; Hashim, Abdul Hakim Bin

    Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride (TiN) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation technique. We studied and discussed the effect of various nitrogen gas flow rates on microstructural and mechanical properties of TiN-coated HSS coupons. The coating properties investigated in this work included the surface morphology, thickness of deposited coating, adhesion between the coating and substrate, coating composition, coating crystallography, hardness and surface characterization using a field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD) with glazing incidence angle (GIA) technique, scratch tester, hardness testing machine, surface roughness tester, and atomic force microscope (AFM). An increase in the nitrogen gas flow rate showed decrease in the formation of macro-droplets in CAE PVD technique. During XRD-GIA studies, it was observed that by increasing the nitrogen gas flow rate, the main peak [1,1,1] shifted toward the lower angular position. Surface roughness decreased with an increase in nitrogen gas flow rate but was higher than the uncoated polished sample. Microhardness of TiN-coated HSS coupons showed more than two times increase in hardness than the uncoated one. Scratch tester results showed good adhesion between the coating material and substrate. Considerable improvement in the properties of TiN-deposited thin films was achieved by the strict control of all operational steps.

  20. High-speed AC motors

    Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)

    1997-12-31

    The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.

  1. High-speed motion neutron radiography

    A system has been developed to perform neutron radiographic analysis of dynamic events having a duration of several milliseconds. The system has been operated in the range of 2000 to 10,000 frames. Synchronization has provided high-speed motion neutron radiographs for evaluation of the firing cycles of 7.62-mm munition rounds within a thick steel rifle barrel. The system has also been used to demonstrate its ability to produce neutron radiographic movies of two-phase flow. The equipment includes a TRIGA reactor capable of pulsing to a peak power of 3000 MW, a neutron beam collimator, a scintillator neutron conversion screen coupled to an image intensifier, and a 16-mm high-speed movie camera. The peak neutron flux incident at the object position is about 4 X 1011 n/cm2 X s with a pulse, full-width at half-maximum, of 9 ms. Modulation transfer function techniques have been used to assist optimization of the system performance. Special studies have been performed on the scintillator conversion screens and on the effects of statistical limitations on information availability

  2. 铌对喷射成形 M3∶2高速钢组织和耐磨性的影响%Effect of Nb on microstructure and wear resistance of spray-formed M 3∶2 high speed steel

    张程; 黄进峰; 吴健安; 连勇; 王和斌; 张济山; 李书开; 王宏亮

    2016-01-01

    研究了Nb对喷射成形高速钢M 3∶2组织和硬度的影响,并对含Nb喷射成形高速钢在不同温度下的摩擦行为进行了研究。结果表明,Nb可以使一次MC型碳化物变得更细小、球形度更好,M2 C片层厚度变薄,有利于高速钢回火过程中的二次析出,提高其回火硬度。0.5%Nb的添加可显著提高喷射成形M3∶2高速钢的耐磨性。常温(20℃)时高速钢的磨损机制主要为磨粒磨损;中温(300℃)时,磨损机制则以粘着磨损为主,氧化磨损增加;高温(500℃)时,主要以氧化磨损为主。%Effect of niobium on microstructure and hardness of spray formed M3∶2 high speed steel was investigated. And the wear behavior of M3∶2 high speed steel with Nb at different temperature is also discussed.The results show that the addition of niobium can make MC carbides smaller and more spherical, and M2 C lamellar more thinner, which is helpful for secondary precipitation of high speed steel during tempering and improving the hardness after tempering.With the temperature increased, the M3-0.5Nb high speed steel presents better wear resistance than that of the M3 steel.Wear mechanism of the high speed steels is depends on the temperature.At room temperature, abrasive wear dominates;near 300℃, it transfer to adhesive wear, and the oxidation wear gradually increases.At higher temperature, near 500℃, the wear mechanism is oxidation wear accompanied with some abrasive wear and adhesive wear.

  3. Reciprocal sliding wear of SiC particle reinforced Al-Cu aluminium matrix composites against stainless steel, high speed tool steel and ceramics. Pt. 1. Tribological properties and construction of tribo-maps

    Bai Mingwu [Lab. of Solid Lubrication, Lanzhou Inst. of Chemical Physics, Lanzhou (China); Xue Qunji [Lab. of Solid Lubrication, Lanzhou Inst. of Chemical Physics, Lanzhou (China); Guo Huifang [Inst. of Powder Metallurgy, Central-South Univ. of Technology, Changsha (China)

    1996-07-01

    The SiC particle reinforced Al-Cu aluminum matrix composites were dry sliding against 4Cr13, W{sub 18}Cr{sub 4}V steel and Si{sub 3}N{sub 4} ceramics on a reciprocal sliding wear testing machine at ambient conditions. Experiments were performed within a normal load range of 20 to 175 N and a sliding velocity of 0.075 to 1.2 m s{sup -1}. It was found that there was a big friction coefficient and friction fluctuation at low reciprocal velocity and very low friction coefficient at very high reciprocal velocity. The composite pins in composite/W{sub 18}Cr{sub 4}V tribo-pairs had greatest wear resistance in three kinds of tribo-pairs. The wear maps of the three kinds of tribo-pairs constructed to illustrate the sliding wear characteristics of the composites. (orig.)

  4. Application Of High Speed Photography In Science And Technology

    Wu Ji-Zong, Wu; Yu-Ju, Lin

    1983-03-01

    The service works in high-speed photography carried out by the Department of Precision Instruments, Tianjin University are described in this paper. A compensation type high-speed camera was used in these works. The photographic methods adopted and better results achieved in the studies of several technical fields, such as velocity field of flow of overflow surface of high dam, combustion process of internal combustion engine, metal cutting, electrical are welding, experiment of piling of steel tube piles for supporting the marine platforms and characteristics of motion of wrist watch escape mechanism and so on are illustrated in more detail. As the extension of human visual organs and for increasing the abi-lities of observing and studying the high-speed processes, high-speed photography plays a very important role. In order to promote the application and development on high-speed photography, we have carried out the consultative and service works inside and outside Tianjin Uni-versity. The Pentazet 35 compensation type high-speed camera, made in East Germany, was used to record the high-speed events in various kinds of technical investigations and necessary results have been ob-tained. 1. Measurement of flow velocity on the overflow surface of high dam. In the design of a key water control project with high head, it is extremely necessary to determinate various characteristics of flow velocity field on the overflow surface of high dam. Since the water flow on the surface of high overflow dam possesses the features of large flow velocity and shallow water depth, therefore it is difficult to use the conventional current meters such as pilot tube, miniature cur-rent meter or electrical measuring methods of non-electrical quantities for studying this problem. Adopting the high-speed photographic method to study analogously the characteristics of flow velocity field on the overflow surface of high dam is a kind of new measuring method. People

  5. High-speed data search

    Driscoll, James N.

    1994-01-01

    The high-speed data search system developed for KSC incorporates existing and emerging information retrieval technology to help a user intelligently and rapidly locate information found in large textual databases. This technology includes: natural language input; statistical ranking of retrieved information; an artificial intelligence concept called semantics, where 'surface level' knowledge found in text is used to improve the ranking of retrieved information; and relevance feedback, where user judgements about viewed information are used to automatically modify the search for further information. Semantics and relevance feedback are features of the system which are not available commercially. The system further demonstrates focus on paragraphs of information to decide relevance; and it can be used (without modification) to intelligently search all kinds of document collections, such as collections of legal documents medical documents, news stories, patents, and so forth. The purpose of this paper is to demonstrate the usefulness of statistical ranking, our semantic improvement, and relevance feedback.

  6. Exploring of Chinese High-speed Railways

    liuYoumei

    2004-01-01

    Based ion experiences of high-speed railways in foreign countries,the speed-raise situation of the Chinese railways,the research & development and test of high-speed transportation carries,as well as the prospective of high-speed railway in China are introduced.

  7. Towards high-speed scanning tunneling microscopy

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  8. 铌对喷射成形M3:2型高速钢组织和性能的影响%Effect of niobium on the microstructure and properties of spray-formed M3:2 high speed steel

    卢林; 黄进峰; 侯陇刚; 张金祥; 王和斌; 崔华; 张济山

    2014-01-01

    AISI M3:2 high speed steels with or without niobium addition were prepared via spray forming, then subjected to forging processes. The effects of Nb on the microstructure and properties of the high speed steels were investigated by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. It is found that Nb addition can refine the microstructure of the as-deposited steels and decrease the size of M2 C eutectic carbides. The amount of MC carbides in the as-deposited steels increases with increasing Nb content. The tempering resistance and second hardening ability of the high speed steel are improved by Nb addition. With a 1% Nb addition, lots of bulk Nb-rich primary MC carbides can form, which becomes the main cause of the reduction in bending strength and impact toughness of the high speed steel. However, the best mechanical properties can be achieved in the presence of 0. 5% Nb.%采用喷射成形工艺制备了含铌和不含铌M3:2型高速钢,然后进行锻造加工.利用扫描电子显微镜、X射线能谱仪、X射线衍射仪等研究了铌对喷射成形M3:2型高速钢组织和性能的影响.铌的加入细化了沉积态的组织,减小了M2 C共晶碳化物尺寸,而对M2 C的成分影响不明显.沉积态中MC碳化物的数量随铌含量提高而增多,且其成分变化显著.铌的加入可以提高喷射成形M3:2型高速钢的抗回火软化性和二次硬化能力.但是,当铌质量分数为1%时,组织中形成数量较多且难以破碎的以铌为主的块状MC碳化物,导致钢的弯曲强度和冲击韧性下降.铌质量分数为0.5%的喷射成形M3:2型高速钢可以获得最佳的硬度、弯曲强度和冲击韧性.

  9. Gradient tool WC/HS6-5-2 materials produced using the powder metallurgy method

    L.A. Dobrzański; A. Kloc-Ptaszna; G. Matula

    2008-01-01

    Purpose: The goal of this work is development of the new group of the gradient cermets with the high-speed steelmatrix, reinforced with the hard carbides phases of the WC types.Design/methodology/approach: The materials were fabricated using the conventional powder metallurgymethod, consisting in compacting the powder in a closed die, and subsequent sintering. All the sintered test pieces weresubjected to examination of density and hardness; observations were also made using the scanning elec...

  10. 喷射成形含铌 M3型高速钢的组织和耐磨性%Microstructure and wear resistance of spray-formed M3 high speed steel with niobium addition

    王和斌; 侯陇刚; 卢林; 张金祥; 崔华; 黄进峰; 张济山

    2015-01-01

    采用喷射成形技术制备了 M3型高速钢和以 Nb 替代 V 的 M3型高速钢。利用扫描电镜、X 射线衍射、差示扫描量热仪和金相显微镜研究了 Nb 对 M3型高速钢组织的影响。喷射成形能有效消除宏观偏析,细化组织。以 Nb 代 V,提高了 MC 型碳化物开始析出温度,大量 MC 相先于共晶反应析出,呈独立的近球形分布于晶界,同时其尺寸减小。由于消耗大量 C,抑制了共晶反应,M2 C 片层数量减少且厚度变薄,其在热变形过程中更易于分解,进一步增加了组织均匀性。低温低载荷时含铌的 M3型高速钢抗磨损性能显著优于 M3高速钢,温度升高到500℃时磨损机制逐渐以氧化磨损为主,两合金的抗磨损性能差距减小,主要原因是大量呈弥散球形分布的含铌 MC 型碳化物能有效提高高速钢的磨粒磨损抗性,而其对抗氧化性能并无明显作用。%M3 high speed steel (HSS) with or without niobium addition was prepared by spray forming, and the effect of niobium on the microstructure of M3 HSS was investigated by scanning electron microscopy ( SEM) combined with energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) analysis, differential scanning calorimetry (DSC) and optical microscopy (OM). Fi-ner and uniformly-distributed grains without macrosegregation appear in the as-deposited HSS, and the addition of niobium tends to shift the precipitation of primary MC-type carbides to a higher temperature. Plenty of refined niobium-containing MC carbides precipi-tate as isolated sphere particles in the grain boundaries before onset of eutectic reaction. Niobium mainly appears in primary MC-type carbides by consuming carbon, which suppresses the degree of eutectic reaction to a large extent, leading to the decrease in both amount and size of M2 C lamella carbides. The refined metastable M2 C carbides in Nb-containing HSS can be completely decomposed easily during hot deformation, and the

  11. Dynamic analysis of soil-steel composite bridges for high speed railway traffic : Case study of a bridge in Märsta, using field measurements and FE-analysis

    Mellat, Peyman

    2012-01-01

    Soil-steel composite bridge refers to structures where a buried flexible corrugated steel pipe works in composite action with the surrounding soil. These structures are being increasingly used in road and railway projects as an alternative to standard type bridges, e.g. short- and medium span concrete beam- and portal frame bridges. On account of their economic advantage and short and easy construction operation, soil-steel composite bridges are getting more popular as railway crossings locat...

  12. Workpiece structure deformation caused by high speed cutting

    Kopač, Janez

    2015-01-01

    The hard turning and grinding of High Speed Steel (HSS) materials with hardness of 61 HRC significantly changes structural properties. Estimators of the cutting conditions are surface roughness, dimensions, tolerances and required structure of the surface layer. Vacuum heat treatment of HSS for cold working applications was used as yielded material with greater toughness, while the hardness was maintained constant or even increased. HSS-BRM2 material that was vacuum quenched and tempered was ...

  13. Cutting tool materials for high speed machining

    LIU Zhanqiang; AI Xing

    2005-01-01

    High speed machining (HSM) is one of the emerging cutting processes, which is machining at a speed significantlyhigher than the speed commonly in use on the shop floor. In the last twenty years, high speed machining has received great attentions as a technological solution for high productivity in manufacturing. This article reviews the developments of tool materials in high speed machining operations, and the properties, applications and prospective developments of tool materials in HSM are also presented.

  14. Towards high-speed scanning tunneling microscopy

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices is shown using finite-element simulations, combined with measurements of their resonance frequency and actuation range. Tip deposition was done using EBID (Electron-Beam Induced Deposition) which a...

  15. Review of high speed communications photomultiplier detectors

    Enck, R. S.; Abraham, W. G.

    1978-01-01

    Four types of newly developed high speed photomultipliers are discussed: all electrostatic; static crossed field; dynamic crossed field; and hybrid (EBS). Design, construction, and performance parameters of each class are presented along with limitations of each class of device and prognosis for its future in high speed light detection. The particular advantage of these devices lies in high speed applications using low photon flux, large cathode areas, and broadband optical detection.

  16. High Speed On-Wafer Characterization Laboratory

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  17. Comparison of High Speed Congestion Control Protocols

    Jawhar Ben Abed

    2012-10-01

    Full Text Available Congestion control limits the quantity of information input at a rate less important than that of thetransmission one to ensure good performance as well as protect against overload and blocking of thenetwork. Researchers have done a great deal of work on improving congestion control protocols,especially on high speed networks.In this paper, we will be studying the congestion control alongside low and high speed congestion controlprotocols. We will be also simulating, evaluating, and comparing eight of high speed congestion controlprotocols : Bic TCP, Cubic TCP, Hamilton TCP, HighSpeed TCP, Illinois TCP, Scalable TCP,Compound TCP and YeAH TCP, with multiple flows.

  18. Reducing Heating In High-Speed Cinematography

    Slater, Howard A.

    1989-01-01

    Infrared-absorbing and infrared-reflecting glass filters simple and effective means for reducing rise in temperature during high-speed motion-picture photography. "Hot-mirror" and "cold-mirror" configurations, employed in projection of images, helps prevent excessive heating of scenes by powerful lamps used in high-speed photography.

  19. Nanocrystalline Ni-Co Alloy Synthesis by High Speed Electrodeposition

    Jamaliah Idris

    2013-01-01

    Full Text Available Electrodeposition of nanocrystals is economically and technologically viable production path for the synthesis of pure metals and alloys both in coatings and bulk form. The study presents nanocrystalline Ni-Co alloy synthesis by high speed electrodeposition. Nanocrystalline Ni-Co alloys coatings were prepared by direct current (DC and deposited directly on steel and aluminum substrates without any pretreatment, using high speed electrodeposition method. The influence of the electrolysis parameters, such as cathodic current density and temperature at constant pH, on electrodeposition and microstructure of Ni-Co alloys were examined. A homogeneous surface morphology was obtained at all current densities of the plated samples, and it was evident that the current density and temperature affect the coating thickness of Ni-Co alloy coatings.

  20. Designing for High-Speed Ships

    Røed, Bjarte Knappen

    2007-01-01

    Fast patrol boats are high-speed vessels operated by the Royal Norwegian Navy (RNoN). These ships are 36,5 meters long, have a beam of 6,2 meters and operate at high speed (32 knots – 16,5 meters per second) in very restricted waters. The fast patrol boats are war ships and navigation tasks performed by the crews are different from those in civilian high-speed craft. A team of five persons navigate the fast patrol boats, and navigation is based on traditional means such as visual observations...

  1. On China's High-Speed Railway Technology

    You-tong FANG

    2011-01-01

    Energy and environmental issues have become increasingly prominent in matters of transportation.Compared with road,air,and sea transportation,railway transportation has the advantages of a large transmission capacity,with rapid,safe,and on-time travel,requiring less land resources,with lower energy consumption,less environmental pollution,and the capacity to operate under most weather conditions.In particular,high-speed railway technology has been growing rapidly.Since the world's first high-speed railway was built in Japan in 1964,more than ten countries and regions have developed high-speed railways,operating over a total of more than 10000 km.High-speed railways not only provide the public with a new type of rapid,convenient,safe,and comfortable travel,but also greatly boost the socio-economic development of the country.

  2. SSC high speed communication channel and interconnects

    This paper investigates potential metallic and optical technology applications in SSC high speed interconnects and/or communication channels. Primary focus will be placed on evaluating several metallic and optical interconnect structures. 7 refs., 3 figs

  3. Nonlinear multiple regression model of stainless steel tube magnetic control high-speed TIG welding%不锈钢管磁控高速TIG焊多元非线性回归模型

    路林; 常云龙; 李英民; 路明; 杨旭

    2012-01-01

    采用多元非线性回归正交组合的方法,对不锈钢焊管高速钨极氩弧焊不填充焊丝时外加横向磁场对焊接质量的影响进行试验研究.将焊缝抗拉强度与焊缝成形系数(熔宽/熔深)作为影响焊缝质量的主要考察指标.以磁场强度、氩气流量作为因素,并分析二者之间的相互制约关系.通过正交设计了9组试验,根据回归设计理论,建立二元二次非线性回归方程并进行了剩余标准差计算.结果表明,回归模型能够实现对焊接接头抗拉强度与焊缝成形系数的有效预测.并绘制了其三维视图,在模型的基础上研究磁场强度变化对焊缝质量的影响规律.%In order to study the influence of high-speed argon tungsten-arc welding by transverse magnetic field on quality of stainless pipe welding joint,the test has been realized using multivariable nonlinear regression orthogonal combination method.The welding joint tensile strength and form factor of weld(the weld width/penetration) were considered as important assessment factors of weld quality.The magnetic field strength and argon flow were taken to be considered,and the relationship between them was then analyzed.Nine groups of testing were designed by orthogonal method,according to regression design theory, the binary quadratic nonlinear regression equation was established and the remaining standard deviation was calculated.The experimental results showed that regression models could realize the forecast of welding joint tensile strength and form factor of weld.Finally,the three-dimensional view was made and the influence of magnetic field strength changing regularity on weld quality was studied.

  4. Effect of increased nitrogen content on the structure and properties of tool steels

    M. Cieśla

    2008-07-01

    Full Text Available Purpose: The influence is analysed of an increased nitrogen content in the range of 0.03-0.09% on stereological features of the microstructure, the principal mechanical properties, crack resistance and fatigue strength of alloy tool steels of X155CrMoV12-1 and X40CrMoV5-1 types, and the HS 6-5-2 high-speed steel.Design/methodology/approach: The principal stereological parameters of precipitates in the microstructure of as-annealed, quenched and tempered tool steels with nitrogen have been determined. The surface fraction and the mean plane section area of carbides have been determined as well. The influence of nitrogen on abrasion resistance, crack resistance and low-cycle fatigue of a heat improved steel has been examined.Findings: It has been found that in the investigated tool and high-speed steels, a nitrogen addition enhances size-reduction and homogenization of the structure in the as-quenched and as-tempered condition. Moreover, an advantageous effect of nitrogen additions has been found on increasing the fraction and dispersion of carbides in the as-annealed condition. The tool and high-speed steels with a nitrogen addition have shown increased resistance to abrasion and brittle cracking as well as longer fatigue life at an elevated temperature.Practical implications: At the laboratory testing stage, the results of the study may constitute an assessment of the effect of nitrogen addition on usable properties of tool steels. The results should be used to develop a production technology of tool steels containing nitrogen of increased durability in operational conditions.Originality/value: The study has shown the influence of a nitrogen addition in the range of 0.03-0.09% on the modification of the microstructe of selected tool and high-speed steels, which determines the enhanced usable properties of those steels.

  5. High Speed Wireless Signal Generation and Demodulation

    Caballero Jambrina, Antonio; Sambaraju, Rakesh; Zibar, Darko;

    We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation.......We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation....

  6. Congestion control of high-speed networks

    1993-06-01

    We report on four areas of activity in the past six months. These areas include the following: (1) work on the control of integrated video and image traffic, both at the access to a network and within a high-speed network; (2) more general/game theoretic models for flow control in networks; (3) work on fault management for high-speed heterogeneous networks to improve survivability; and (4) work on all-optical (lightwave) networks of the future, designed to take advantage of the enormous bandwidth capability available at optical frequencies.

  7. Performance of High-Speed Grease Lubricated Hybrid Ceramic Ball Bearing

    李秀娟; 王黎钦; 古乐

    2004-01-01

    To simplify the lubricating system for high-speed bearings and improve its reliability, grease lubricated high-speed hybrid ceramic bearings were theoretically and experimentally researched.Bearings with an outer race of 62 mm and eleven 9.525-mm balls were investigated.Traction coefficient and flash temperature between the bearing races and the balls were calculated and the results show that the traction coefficient of Si3N4 hybrid ceramic bearings is 74% that of the steel AISI 440B ones at 30 000 r/min and 1750 N, and the flash temperature of the hybrid bearings is 49% that of steel ones.Simulating the high-speed bearing rotational conditions, the grease lubricated hybrid ceramic ball bearings were tested and the results show that the power consumption of hybrid ceramic bearing lubricated by grease D at 24 000 r/min and axial load 1750 N is 80% that of steel ones.

  8. Aerodynamic design on high-speed trains

    Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li

    2016-04-01

    Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

  9. High-speed Power Line Communications

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  10. High-Speed Rail & Air Transport Competition

    Adler, Nicole; Nash, Chris; Pels, Eric

    2008-01-01

    This paper develops a methodology to assess transport infrastructure investments and their effects on a Nash equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub and spoke legacy airlines and low cost carriers,

  11. High-speed fiber grating pressure sensors

    Udd, Eric; Rodriguez, George; Sandberg, Richard L.

    2014-06-01

    Fiber grating pressure sensors have been used to support pressure measurements associated with burn, deflagration and detonation of energetic materials. This paper provides an overview of this technology and serves as a companion paper to the application of this technology to measuring pressure during high speed impacts.

  12. High-speed massively parallel scanning

    Decker, Derek E.

    2010-07-06

    A new technique for recording a series of images of a high-speed event (such as, but not limited to: ballistics, explosives, laser induced changes in materials, etc.) is presented. Such technique(s) makes use of a lenslet array to take image picture elements (pixels) and concentrate light from each pixel into a spot that is much smaller than the pixel. This array of spots illuminates a detector region (e.g., film, as one embodiment) which is scanned transverse to the light, creating tracks of exposed regions. Each track is a time history of the light intensity for a single pixel. By appropriately configuring the array of concentrated spots with respect to the scanning direction of the detection material, different tracks fit between pixels and sufficient lengths are possible which can be of interest in several high-speed imaging applications.

  13. Pulse Detonation Engines for High Speed Flight

    Povinelli, Louis A.

    2002-01-01

    Revolutionary concepts in propulsion are required in order to achieve high-speed cruise capability in the atmosphere and for low cost reliable systems for earth to orbit missions. One of the advanced concepts under study is the air-breathing pulse detonation engine. Additional work remains in order to establish the role and performance of a PDE in flight applications, either as a stand-alone device or as part of a combined cycle system. In this paper, we shall offer a few remarks on some of these remaining issues, i.e., combined cycle systems, nozzles and exhaust systems and thrust per unit frontal area limitations. Currently, an intensive experimental and numerical effort is underway in order to quantify the propulsion performance characteristics of this device. In this paper, we shall highlight our recent efforts to elucidate the propulsion potential of pulse detonation engines and their possible application to high-speed or hypersonic systems.

  14. High speed functional magnetic resonance imaging

    Gibson, A M

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated by reference, within the Magnetic Resonance Centre at the University of Nottingham during the period from October 1998 to October 2001. This thesis documents the implementation and application of a novel high-speed imaging technique, the multi-slice, echo shifted, echo planar imaging technique. This was implemented on the Nottingham 3 T imaging system, for functional magnetic resonance imaging. The technique uses echo shifting over the slices in a multi-slice echo planar imaging acquisition scheme, making the echo time longer than the repetition time per slice. This allows for rapid volumar sampling of the blood oxygen level dependent effect in the human brain. The new high-speed technique was used to investigate the variability of measuring the timing differences between haemodynamic responses, at the same cortical location, to simple cued motor tasks. The technique was also used in an investigation into motor cortex functional connect...

  15. High speed printing with polygon scan heads

    Stutz, Glenn

    2016-03-01

    To reduce and in many cases eliminate the costs associated with high volume printing of consumer and industrial products, this paper investigates and validates the use of the new generation of high speed pulse on demand (POD) lasers in concert with high speed (HS) polygon scan heads (PSH). Associated costs include consumables such as printing ink and nozzles, provisioning labor, maintenance and repair expense as well as reduction of printing lines due to high through put. Targets that are applicable and investigated include direct printing on plastics, printing on paper/cardboard as well as printing on labels. Market segments would include consumer products (CPG), medical and pharmaceutical products, universal ID (UID), and industrial products. In regards to the POD lasers employed, the wavelengths include UV(355nm), Green (532nm) and IR (1064nm) operating within the repetition range of 180 to 250 KHz.

  16. DAC 22 High Speed Civil Transport Model

    1992-01-01

    Between tests, NASA research engineer Dave Hahne inspects a tenth-scale model of a supersonic transport model in the 30- by 60-Foot Tunnel at NASA Langley Research Center, Hampton, Virginia. The model is being used in support of NASA's High-Speed Research (HSR) program. Langley researchers are applying advance aerodynamic design methods to develop a wing leading-edge flap system which significantly improves low-speed fuel efficiency and reduces noise generated during takeoff operation. Langley is NASA's lead center for the agency's HSR program, aimed at developing technology to help U.S. industry compete in the rapidly expanding trans-oceanic transport market. A U.S. high-speed civil transport is expected to fly in about the year 2010. As envisioned, it would fly 300 passengers across the Pacific in about four hours at Mach 2.4 (approximately 1,600 mph/1950 kph) for a modest increase over business class fares.

  17. Nanometer lapping technology at high speed

    YANG JianDong; TIAN ChunLin; WANG ChangXing

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abrasives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  18. Safety issues in high speed machining

    1994-05-01

    There are several risks related to High-Speed Milling, but they have not been systematically determined or studied so far. Increased loads by high centrifugal forces may result in dramatic hazards. Flying tools or fragments from a tool with high kinetic energy may damage surrounding people, machines and devices. In the project, mechanical risks were evaluated, theoretic values for kinetic energies of rotating tools were calculated, possible damages of the flying objects were determined and terms to eliminate the risks were considered. The noise levels of the High-Speed Machining center owned by the Helsinki University of Technology (HUT) and the Technical Research Center of Finland (VTT) in practical machining situation were measured and the results were compared to those after basic preventive measures were taken.

  19. Compressibility, turbulence and high speed flow

    Gatski, Thomas B

    2013-01-01

    Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and

  20. High-speed milling of light metals

    F. Cus; U. Zuperl; V. Gecevska

    2007-01-01

    Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operati...

  1. Intrusion Detection in High-Speed Networks

    Riegel, Martin; Walsø, Claes Lyth

    2007-01-01

    This thesis investigates methods for implementing an intrusion detection system (IDS) in a high-speed backbone network. The work presented in this report is run in cooperation with Kripos and Uninett. The popular IDS software, Snort, is deployed and tested in Uninett's backbone network. In addition, the monitoring API (MAPI) is considered as a possible IDS implementation in the same environment. The experiments conducted in this report make use of the programmable DAG card, which is a passive...

  2. A High-Speed Information Retrieval System

    SHI Shu-dong; LI Zhi-tang

    2004-01-01

    We cleveloped a high-speed information retrieval system. The system hased on the IXP 2800 is one of the dedicute device. The velocily of the information retrieval is 6.8 Gb/s. The protocol support Telnet, FTP, SMTP, POP3 etc. various networks protocols. The information retrieval supports the key word and the natural language process. This paper explains the hardware system, software system and the index of the performance.

  3. High-speed milling of light metals

    F. Cus

    2007-01-01

    Full Text Available Purpose: Purpose of this paper: Introduction applicability of high-speed cutting of light metals is presented inthis paper.Design/methodology/approach:HSC is the result of numerous technical advances ensuring that milling hasbecome faster than conventional milling and has gained importance as a cutting process. The advantages ofthe HSC milling are higher productivity owing to the reduction of machining times increase of the flow timeof production, reduction of the number of technological operations, increase of the surface quality and longerservice life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/minrequire modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in theautomobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also theachievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficientmachining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling canbe compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and morefrequently used in practice. This result is high quality of the surface and shorter machining times. In some caseswhen machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum andmagnesium alloying materials are machined.

  4. Architectures and applications of high-speed vision

    Watanabe, Yoshihiro; Oku, Hiromasa; Ishikawa, Masatoshi

    2014-11-01

    With the progress made in high-speed imaging technology, image processing systems that can process images at high frame rates, as well as their applications, are expected. In this article, we examine architectures for high-speed vision systems, and also dynamic image control, which can realize high-speed active optical systems. In addition, we also give an overview of some applications in which high-speed vision is used, including man-machine interfaces, image sensing, interactive displays, high-speed three-dimensional sensing, high-speed digital archiving, microvisual feedback, and high-speed intelligent robots.

  5. Fatigue resistance of welded joints in aluminium high-speed craft: A total stress concept

    Den Besten, J.H.

    2015-01-01

    Crew transfers, surveillance duties and {security, rescue, interception} operations at sea typically require high-speed craft. Aluminium is quite often selected as hull structure material because of its weight save potential in comparison to steel. The fatigue strength, however, may become a point o

  6. High-speed milling of light metals

    F. Cus

    2007-09-01

    Full Text Available Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operations, increase of the surface quality and longer service life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/min require modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in the automobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also the achievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficient machining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling can be compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and more frequently used in practice. This result is high quality of the surface and shorter machining times. In some cases when machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum and magnesium alloying materials are machined.

  7. High speed UNIBUS-VME interface

    An interface between VME an the UNIBUS of PDP or VAX computer is presented. The system supports high speed parallel communication (up to 1MB/S) and is composed of two modules. One of these is a commercial DR11M board which performs DMA transfers between UNIBUS and the external word. The other is a VME module specifically developed for this application. The interface has been tested under VMS operating system in VAX and VALET-PLUS system for the VME Bus. We describe in detail the VME module and its connection with the DR11M. Software, both in WMS and VALET, is also described. (Author) 7 refs

  8. High Speed SPM of Functional Materials

    Huey, Bryan D. [Univ. of Connecticut, Storrs, CT (United States)

    2015-08-14

    The development and optimization of applications comprising functional materials necessitates a thorough understanding of their static and dynamic properties and performance at the nanoscale. Leveraging High Speed SPM and concepts enabled by it, efficient measurements and maps with nanoscale and nanosecond temporal resolution are uniquely feasible. This includes recent enhancements for topographic, conductivity, ferroelectric, and piezoelectric properties as originally proposed, as well as newly developed methods or improvements to AFM-based mechanical, friction, thermal, and photoconductivity measurements. The results of this work reveal fundamental mechanisms of operation, and suggest new approaches for improving the ultimate speed and/or efficiency, of data storage systems, magnetic-electric sensors, and solar cells.

  9. Accident Safety Design for High Speed Elevator

    Tawiwat Veeraklaew

    2012-12-01

    Full Text Available There have been many elevators exist in buildings for such a long time; however, an accident might happen as a free fall due to lacks of maintenance or some other accident such as firing. Although this situation is rarely occurred, many people are still concerned about it. The question here is how to make passengers to feel safe and confident when they are using an elevator, especially, high speed elevator. This problem is studied here in this paper as a free fall spring-mass-damper system with the stiffness and damping coefficient can be computed as minimum jerk of the system with given constraints on trajectories.

  10. High Speed Solid State Circuit Breaker

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  11. High speed drying of saturated steam

    This paper describes the development of the drying process for the saturated steam used in the PWR nuclear plant turbines in order to prevent negative effects of water on turbine efficiency, maintenance costs and equipment lifetime. The high speed drying concept is based on rotating the incoming saturated steam in order to separate water which is more denser than the steam; the water film is then extracted through an annular slot. A multicellular modular equipment has been tested. Applications on high and low pressure extraction of various PWR plants are described (Bugey, Loviisa)

  12. High-Speed Images of Bubble Formation

    Bunganič, Radovan; Růžička, Marek; Drahoš, Jiří

    Praha : Process Engineering Publisher, 2004, s. 922. ISBN 80-86059-40-5. [International Congress of Chemical and Process Engineering CHISA 2004 /16./. Praha (CZ), 22.08.2004-26.08.2004] R&D Projects: GA ČR GA104/04/0827; GA ČR GD104/03/H141 Grant ostatní: BEMUSAC(XE) G1MA/CT/2002/04019 Institutional research plan: CEZ:AV0Z4072921 Keywords : bubble formation * high-speed image Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  13. A high speed magnetostrictive mirror deflector

    This paper discusses the development of a high speed magnetostrictive mirror deflector that is compact, power efficient, and requires only low voltage for excitation. The magnetostrictive mirror deflector was designed and fabricated, and its performance tested. Three kinds of experiments were conducted to evaluate the performance, namely, identification of resonance frequencies, measurement of the angle of deflection, and study of the stability of the actuator under continuous use. The measurements were made using a high speed charge coupled device camera integrated with a PC using a custom made data acquisition and analysis program. The deflector was able to produce more than 6.1 mrad at 5.28 kHz with a minimal power of 0.8 W. Experiments conducted to test the repeatability of the measurements made have shown that the device is suitable for continuous duty operation. The results obtained in this study showed that the magnetostrictive mirror deflector is a good candidate for lidar and rapidly tunable laser system use

  14. High-speed optogenetic circuit mapping

    Augustine, George J.; Chen, Susu; Gill, Harin; Katarya, Malvika; Kim, Jinsook; Kudolo, John; Lee, Li M.; Lee, Hyunjeong; Lo, Shun Qiang; Nakajima, Ryuichi; Park, Min-Yoon; Tan, Gregory; Tang, Yanxia; Teo, Peggy; Tsuda, Sachiko; Wen, Lei; Yoon, Su-In

    2013-03-01

    Scanning small spots of laser light allows mapping of synaptic circuits in brain slices from transgenic mice expressing channelrhodopsin-2 (ChR2). These light spots photostimulate presynaptic neurons expressing ChR2, while postsynaptic responses can be monitored in neurons that do not express ChR2. Correlating the location of the light spot with the amplitude of the postsynaptic response elicited at that location yields maps of the spatial organization of the synaptic circuits. This approach yields maps within minutes, which is several orders of magnitude faster than can be achieved with conventional paired electrophysiological methods. We have applied this high-speed technique to map local circuits in many brain regions. In cerebral cortex, we observed that maps of excitatory inputs to pyramidal cells were qualitatively different from those measured for interneurons within the same layers of the cortex. In cerebellum, we have used this approach to quantify the convergence of molecular layer interneurons on to Purkinje cells. The number of converging interneurons is reduced by treatment with gap junction blockers, indicating that electrical synapses between interneurons contribute substantially to the spatial convergence. Remarkably, gap junction blockers affect convergence in sagittal cerebellar slices but not in coronal slices, indicating sagittal polarization of electrical coupling between interneurons. By measuring limb movement or other forms of behavioral output, this approach also can be used in vivo to map brain circuits non-invasively. In summary, ChR2-mediated high-speed mapping promises to revolutionize our understanding of brain circuitry.

  15. Surface grinding characteristics of ferrous metals under high-speed and speed-stroke grinding conditions

    Some ferrous metals have been ground under different conditions with high-speed and speed-stroke in surface grinding operation. The paper describes experimental investigation of grinding forces in grinding some ferrous metals with the application of cutting fluids. Grinding tests have been carried out on mild steel, assab steel and stainless steel with different combinations of down feed and cross feed. The wheel speed was 27 m/sec while the table speed was maintained at the maximum possible 25 m/min. The grindability has been evaluated by measuring the grinding forces, grinding ratio, and surface finish. Grinding forces have been plotted against down feed of the grinding wheel and cross feed of the table. It has been observed that the radial and tangential grinding forces in stainless steel were higher than those in assab steel and mild steel

  16. High speed photography of moire fringes. Application to ceramics under impact

    A high speed moire photography system has been developed for measuring dynamic 2-D strain fields. The method is illustrated by an impact onto tiles of silicon carbide to display the history of the strain field. The steel blunt cylinder projectile is fired by a gas gun at a speed of 330 m/s. A checked grating with 28 lines/mm was reproduced on the target lateral surface using aluminum. The moire fringes are recorded during impact by a high speed camera. Sequences of fringe patterns are analyzed by a 2-D Fourier transform method to obtain the strain fields. (orig.)

  17. High speed photography of moire fringes. Application to ceramics under impact

    Bertin-Mourot, T.; Denoual, C.; Deshors, G.; Louvigne, P.F.; Thomas, T. [DGA/DCE/Centre de Recherches et d`Etudes, Arcueil (France). Dept. Materiaux en Conditions Severes

    1997-08-01

    A high speed moire photography system has been developed for measuring dynamic 2-D strain fields. The method is illustrated by an impact onto tiles of silicon carbide to display the history of the strain field. The steel blunt cylinder projectile is fired by a gas gun at a speed of 330 m/s. A checked grating with 28 lines/mm was reproduced on the target lateral surface using aluminum. The moire fringes are recorded during impact by a high speed camera. Sequences of fringe patterns are analyzed by a 2-D Fourier transform method to obtain the strain fields. (orig.). 4 refs.

  18. High speed aluminum wire anodizing and process

    A high speed aluminum wire anodizing machine and process are provided which includes anodizing aluminum wire in an anodizer tank having wire ingress and egress openings. At least two adjacent rotatable wire accumulator drums are provided in the tank, preferably with means for producing a flow of anodizing electrolytes into each of the drums through an end hub thereof and out of the sidewalls of the drums passed circumferential wire separators. An anode is located proximal to the wire ingress opening, preferably in a contact cell which has an adjustable wire egress window. At least one cathode is provided in the tank. The cathode is preferably either between the drums or a pair of cathodes are provided above and below the drums adjacent to the sidewalls thereof, or both

  19. The Silicon Photomultiplier for High Speed Photometry

    Vander Haagen, Gary A.

    2011-05-01

    The Silicon Photomultiplier (SPM) offers sensitivity comparable to conventional photomultipliers with the added advantage of small size, low operating voltages, and robust tolerance to excess/ambient light. A Peltier cooled SPM running at -30°C was used in conjunction with wideband electronics and a 17-inch Astrograph to collect photometric data without a reference star. High speed photometric trials were conducted on eclipsing binary AW UMa demonstrating fast data rate capability. Data shows the SPM exhibits excellent sensitivity, acceptable signal to noise, and bandwidth with sampling times as short as 1 millisecond for brighter targets. Automated digital data acquisition is discussed along with digital signal processing techniques for noise reduction, spectral analysis, and data mining. The SPM demonstrated acceptable signal to noise for fast photometric studies for 8-10th magnitude targets depending on scintillation and background conditions. Future SPM study topics are also discussed.

  20. Evaporation of high speed sporadic meteors

    E. Murad

    2004-01-01

    Full Text Available Recent measurements conducted at the Arecibo Observatory report high-speed sporadic meteors having velocities near 50 km/s. The results seem to indicate a bimodal velocity distribution in the sporadic meteors (maxima at ~20 km/s and ~50 km/s. The particles have a maximum mass of ~1µg. This paper will present an analysis of the ablation of 1µg meteoroids having velocities of 20, 30, 50, and 70 km/s. The calculations show that there is fractionation even for the fast meteoroids, the effect being particularly noticeable for the 1µg sporadic particles, and less so for the heavier particles. The relevance of the calculations to the radar observations of the sporadic meteors will be discussed.

  1. A high-speed avalanche photodiode

    High-speed avalanche photodiodes are widely used in optical communication systems. Nowadays, separate absorption charge and multiplication structure is widely adopted. In this article, a structure with higher speed than separate absorption charge and multiplication structure is reported. Besides the traditional absorption layer, charge layer and multiplication layer, this structure introduces an additional charge layer and transit layer and thus can be referred to as separate absorption, charge, multiplication, charge and transit structure. The introduction of the new charge layer and transit layer brings additional freedom in device structure design. The benefit of this structure is that the carrier transit time and device capacitance can be reduced independently, thus the 3 dB bandwidth could be improved by more than 50% in contrast to the separate absorption charge and multiplication structure with the same size. (semiconductor devices)

  2. High-Speed Atomic Force Microscopy

    Ando, Toshio; Uchihashi, Takayuki; Kodera, Noriyuki

    2012-08-01

    The technology of high-speed atomic force microscopy (HS-AFM) has reached maturity. HS-AFM enables us to directly visualize the structure and dynamics of biological molecules in physiological solutions at subsecond to sub-100 ms temporal resolution. By this microscopy, dynamically acting molecules such as myosin V walking on an actin filament and bacteriorhodopsin in response to light are successfully visualized. High-resolution molecular movies reveal the dynamic behavior of molecules in action in great detail. Inferences no longer have to be made from static snapshots of molecular structures and from the dynamic behavior of optical markers attached to biomolecules. In this review, we first describe theoretical considerations for the highest possible imaging rate, then summarize techniques involved in HS-AFM and highlight recent imaging studies. Finally, we briefly discuss future challenges to explore.

  3. High speed plasma streams in solar wind

    The behavior of the high-speed plasma streams (HSPSs) in the solar wind is investigated during the period of the solar cycles (SCs) nos. 20-22 (1964-1996). The analysis is performed taking into account their frequency of appearance and the following parameters: the durations (in days); the maximum velocities; the velocity gradients; the importance of the streams. The time variation of the HSPS parameters and their occurrence rate shows an 11-years periodicity with some differences between the considered SCs. The even and odd solar 11-year cycles are different in the structure of their maxima, too. The different behavior of the HSPS parameters between even and odd solar cycle could be due to the 22-year solar magnetic cycle. (authors)

  4. Network Based High Speed Product Innovation

    Lindgren, Peter

    In the first decade of the 21st century, New Product Development has undergone major changes in the way NPD is managed and organised. This is due to changes in technology, market demands, and in the competencies of companies. As a result NPD organised in different forms of networks is predicted to...... be of ever-increasing importance to many different kinds of companies. This happens at the same times as the share of new products of total turnover and earnings is increasing at unprecedented speed in many firms and industries. The latter results in the need for very fast innovation and product...... development - a need that can almost only be resolved by organising NPD in some form of network configuration. The work of Peter Lindgren is on several aspects of network based high speed product innovation and contributes to a descriptive understanding of this phenomenon as well as with normative theory on...

  5. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    National Aeronautics and Space Administration — We propose to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight, low voltage beam...

  6. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    National Aeronautics and Space Administration — The main goal of this proposal is to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight,...

  7. Logic design and implementation on high speed data converting

    A kind of high speed data converter was discussed in this paper. Structure of the system, implementation of the design and memory in the system were introduced in details. Such data converters are important units in high speed routers, and this design is a good reference for high speed router designing

  8. High-speed stereoscopy of aurora

    Kataoka, R.; Fukuda, Y.; Uchida, H. A.; Yamada, H.; Miyoshi, Y.; Ebihara, Y.; Dahlgren, H.; Hampton, D.

    2016-01-01

    We performed 100 fps stereoscopic imaging of aurora for the first time. Two identical sCMOS cameras equipped with narrow field-of-view lenses (15° by 15°) were directed at magnetic zenith with the north-south base distance of 8.1 km. Here we show the best example that a rapidly pulsating diffuse patch and a streaming discrete arc were observed at the same time with different parallaxes, and the emission altitudes were estimated as 85-95 km and > 100 km, respectively. The estimated emission altitudes are consistent with those estimated in previous studies, and it is suggested that high-speed stereoscopy is useful to directly measure the emission altitudes of various types of rapidly varying aurora. It is also found that variation of emission altitude is gradual (e.g., 10 km increase over 5 s) for pulsating patches and is fast (e.g., 10 km increase within 0.5 s) for streaming arcs.

  9. CMOS Image Sensors for High Speed Applications

    M. Jamal Deen

    2009-01-01

    Full Text Available Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps.

  10. High precision machining on high speed machines

    J. Kopač

    2007-09-01

    Full Text Available Purpose: Modern Machines for precision products for three dimensional machining have by milling over 20.000 rpm. Differences between hard and soft machining have influences on concept of machines. Stiffness and rigidity are characteristics and variables which caused the precision and quality of machined part.Design/methodology/approach: This paper introduce some of interesting modern machine tools with different concept as DCG (Drive in Centre of Gravity - Mori Seiki, LAF (Look Ahead Function on machine - Sodick, high speed 20.000 – 60.000 rpm, linear drive, etc. The way from idea to machined part will be shown.Findings: To achieve high precision it is necessary to fill out many request function on machine. Results on machined part depend also from machined material (hardness, structure, size of crystals.Research limitations/implications: Engineers job is to prepare the optimal CNC (PNC program on connection of CAD – CAM software’s. After all mentioned factor test work piece is machined and measured.Originality/value: Comparison between results data on plan and measurement shows us the reality and give us decision around high precision product.

  11. Modeling of high-speed electronic devices

    V. G. Kudrya

    2013-09-01

    Full Text Available Introduction. The theme of this publication is the modeling of electronic tools that operate in the frequency range from zero to terahertz and higher. Application of new concepts and technologies, including biotechnology and nanotechnology in the development of monolithic integrated circuits led to a backlog of technologies of projecting from technologies and experimental research and manufacturing. The aim of this work is to develop algorithms for analysis, reflecting not only topological as well as morphological properties of the object, that is designing within the framework of accounting EMI communicational  transmission of energy and information in the volume of the monolithic integrated circuit. Basic steps for constructing the algorithm. The object of design is presented in the form of basic elements, which can be combined with a communication structure. The object of design is presented in the form of basic elements, which can be combined with a communication structure. There are three types of matrix equations: component; component - communication structure; communication structure. Systems of equations are reduced to standardized descriptors of mathematical model by which to understand current of poles and voltage arcs whole set of basic elements. In this way obtained mathematical model that can be implemented in CAD nano and micro technology electronics. Conclusions. Mathematical models of analysis of high-speed digital and analog electronic means. The algorithm allows morphological optimization is to minimize the adverse effects outside the system of electromagnetic interaction between the components and communicator.

  12. Design of very high speed electric generators

    This work approaches the design process of an electric generator suitable for running efficiently at high speed, driven by a turbo shaft.The axial flux concept was used.For the mechanical design of the prototype, cooling capacity and mounting method were considered, looking for simplicity of the parts evolved. Neodymium-iron-boron permanent magnets were used as magnetic source.For the electrical design, a calculation tool was developed in order to predict the prototype electrical parameters and optimize its geometry.The goal was to obtain 1 kW of electric power at a speed of 100,000 rpm.The efficiency and electrical behaviour of the prototype were characterized at speeds between 2,000 rpm and 30,000 rpm and then the behaviour at the design condition was predicted by obtaining an equivalent electric circuit.The estimated load voltage was 237 V as well as an electrical efficiency of 95%.Eddy current effects were not recognized. Increase of the internal resistance and decree of inductance were observed while raising the electric frequency.Finally, an electronic system was developed in order to use the prototype as a c.c. motor. Global performance was measured according to different supply characteristic. An optimum supply voltage was found.A maximum efficiency of 63% was reached.

  13. Sensor study for high speed autonomous operations

    Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan

    2015-06-01

    As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.

  14. Exhaust emissions from high speed passenger ferries

    Cooper, D. A.

    Exhaust emission measurements have been carried out on-board three high-speed passenger ferries (A, B and C) during normal service routes. Ship A was powered by conventional, medium-speed, marine diesel engines, Ship B by gas turbine engines and Ship C conventional, medium-speed, marine diesel engines equipped with selective catalytic reduction (SCR) systems for NO x abatement. All ships had similar auxiliary engines (marine diesels) for generating electric power on-board. Real-world emission factors of NOx, SO2, CO, CO 2, NMVOC, CH4, N2O, NH3, PM and PAH at steady-state engine loads and for complete voyages were determined together with an estimate of annual emissions. In general, Ship B using gas turbines showed favourable NO x, PM and PAH emissions but at the expense of higher fuel consumption and CO 2 emissions. Ship C with the SCR had the lowest NO x emissions but highest NH 3 emissions especially during harbour approaches and stops. The greatest PM and PAH specific emissions were measured from auxiliary engines operating at low engine loads during harbour stops. Since all ships used a low-sulphur gas oil, SO 2 emissions were relatively low in all cases.

  15. High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

    Taveniku, Mikael

    2013-01-01

    A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges. The current generation data recor - ders used within the VLBI community are aging, special-purpose machines that are both slow (do not meet today's requirements) and are very expensive to maintain and operate. Furthermore, they are not easily upgraded to take advantage of commercial technology development, and are not scalable to multiple 10s of Gbit/s data rates required by new applications. The innovation provides a softwaredefined, high-speed data recorder that is scalable with technology advances in the commercial space. It maximally utilizes current technologies without being locked to a particular hardware platform. The innovation also provides a cost-effective way of streaming large amounts of data from sensors to disk, enabling many applications to store raw sensor data and perform post and signal processing offline. This recording system will be applicable to many applications needing realworld, high-speed data collection, including electronic warfare, softwaredefined radar, signal history storage of multispectral sensors, development of autonomous vehicles, and more.

  16. High Speed/ Low Effluent Process for Ethanol

    M. Clark Dale

    2006-10-30

    n this project, BPI demonstrated a new ethanol fermentation technology, termed the High Speed/ Low Effluent (HS/LE) process on both lab and large pilot scale as it would apply to wet mill and/or dry mill corn ethanol production. The HS/LE process allows very rapid fermentations, with 18 to 22% sugar syrups converted to 9 to 11% ethanol ‘beers’ in 6 to 12 hours using either a ‘consecutive batch’ or ‘continuous cascade’ implementation. This represents a 5 to 8X increase in fermentation speeds over conventional 72 hour batch fermentations which are the norm in the fuel ethanol industry today. The ‘consecutive batch’ technology was demonstrated on a large pilot scale (4,800 L) in a dry mill corn ethanol plant near Cedar Rapids, IA (Xethanol Biofuels). The pilot demonstrated that 12 hour fermentations can be accomplished on an industrial scale in a non-sterile industrial environment. Other objectives met in this project included development of a Low Energy (LE) Distillation process which reduces the energy requirements for distillation from about 14,000 BTU/gal steam ($0.126/gal with natural gas @ $9.00 MCF) to as low as 0.40 KW/gal electrical requirements ($0.022/gal with electricity @ $0.055/KWH). BPI also worked on the development of processes that would allow application of the HS/LE fermentation process to dry mill ethanol plants. A High-Value Corn ethanol plant concept was developed to produce 1) corn germ/oil, 2) corn bran, 3) ethanol, 4) zein protein, and 5) nutritional protein, giving multiple higher value products from the incoming corn stream.

  17. Thermographic measurements of high-speed metal cutting

    Mueller, Bernhard; Renz, Ulrich

    2002-03-01

    Thermographic measurements of a high-speed cutting process have been performed with an infrared camera. To realize images without motion blur the integration times were reduced to a few microseconds. Since the high tool wear influences the measured temperatures a set-up has been realized which enables small cutting lengths. Only single images have been recorded because the process is too fast to acquire a sequence of images even with the frame rate of the very fast infrared camera which has been used. To expose the camera when the rotating tool is in the middle of the camera image an experimental set-up with a light barrier and a digital delay generator with a time resolution of 1 ns has been realized. This enables a very exact triggering of the camera at the desired position of the tool in the image. Since the cutting depth is between 0.1 and 0.2 mm a high spatial resolution was also necessary which was obtained by a special close-up lens allowing a resolution of app. 45 microns. The experimental set-up will be described and infrared images and evaluated temperatures of a titanium alloy and a carbon steel will be presented for cutting speeds up to 42 m/s.

  18. High-speed cinematography of gas-metal atomization

    Ting, Jason [ALCOA Specialty Metals Division, 100 Technical Drive, Alcoa Center, PA 15069 (United States)]. E-mail: jason.ting@alcoa.com; Connor, Jeffery [Material Science Engineering Department, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Ridder, Stephen [Metallurgical Processing Group, NIST, 100 Bureau Dr. Stop 8556, Gaithersburg, MD 20899 (United States)

    2005-01-15

    A high-speed cinematographic footage of a 304L stainless steel gas atomization, recorded at the National Institute of Standard and Technology (NIST), was analyzed using a discrete Fourier transform (DFT) algorithm. The analysis showed the gas atomization process possesses two prominent frequency ranges of melt oscillation (pulsation). A low-frequency oscillation in the melt flow occurring between 5.41 and 123 Hz, with a dominant frequency at 9.93 Hz, was seen in the recirculation zone adjacent to the melt orifice. A high-frequency melt oscillation range was observed above 123 Hz, and was more prominent one melt-tip-diameter downstream in the melt atomization image than upstream near the melt tip. This high-frequency range may reflect the melt atomization frequency used to produce finely atomized powder. This range also included a prominent high frequency at 1273 Hz, which dominated in the image further away downstream from the melt tip. This discrete high-frequency oscillation is most probably caused by the aeroacoustic ''screech'' phenomenon, intrasound (<20 kHz), a result of the atomizing gas jets undergoing flow resonance. It is hypothesized that this discrete intrinsic aeroacoustic tone may enhance melt breakup in the atomization process with evidence of this fact in the melt images.

  19. Avaliação da geração de microtrincas do aço rápido ABNT M2 no processo EDM com adição de SiC = Evaluation of microcrack formation of ABNT M2 high speed steel in the EDM process, with addition of silicon carbide powder

    Jean Robert Pereira Rodrigues

    2008-07-01

    to study the effect of the addition of SiC powder into several dielectric fluids, on microcrack formation of high-speed steel (ABNT M2, during electrical discharge machining. The results show that the samples machined with the addition of SiC powders presentedsignificant reduction in the number of microcracks in the machined surface, when compared with those machined with conventional EDM.

  20. Chicago-St. Louis high speed rail plan

    The Illinois Department of Transportation (IDOT), in cooperation with Amtrak, undertook the Chicago-St. Louis High Speed Rail Financial and Implementation Plan study in order to develop a realistic and achievable blueprint for implementation of high speed rail in the Chicago-St. Louis corridor. This report presents a summary of the Price Waterhouse Project Team's analysis and the Financial and Implementation Plan for implementing high speed rail service in the Chicago-St. Louis corridor

  1. Chicago-St. Louis high speed rail plan

    Stead, M.E.

    1994-12-31

    The Illinois Department of Transportation (IDOT), in cooperation with Amtrak, undertook the Chicago-St. Louis High Speed Rail Financial and Implementation Plan study in order to develop a realistic and achievable blueprint for implementation of high speed rail in the Chicago-St. Louis corridor. This report presents a summary of the Price Waterhouse Project Team`s analysis and the Financial and Implementation Plan for implementing high speed rail service in the Chicago-St. Louis corridor.

  2. 33 CFR 84.24 - High-speed craft.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false High-speed craft. 84.24 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.24 High-speed craft. (a) The masthead light of high-speed craft with a length to breadth ratio of less than 3.0 may be placed at...

  3. High-speed rail-coming to America?

    Cameron, David Ossian

    2009-01-01

    The United States lags many parts of the world when it comes to high-speed rail. But investing in high-speed rail could help us through current problems. Funds- $8 billion-in the economic stimulus package passed by Congress are designated for high-speed rail. Other funds in the pipeline total approximately $15.5 billion. High-speed rail can relieve congestion, free up national airspace, provide reliable transportation and positive economic development, create jobs, and is more energy efficient than other modes of travel. PMID:19608527

  4. Design of A Novel High Speed Dynamic Comparator with Low Power Dissipation for High Speed ADCs

    Sougata Ghosh

    2013-01-01

    Full Text Available A new CMOS dynamic comparator using dual input single output differential amplifier as latch stage suitable for high speed analog-to-digital converters with High Speed, low power dissipation and immune to noise than the previous reported work is proposed. Back to-back inverter in the latch stage is replaced with dual-input single output differential amplifier. This topology completely removes the noise that is present in the input. The structure shows lower power dissipation and higher speed than the conventional comparators. The circuit is simulated with 1V DC supply voltage and 250 MHz clock frequency. The proposed topology is based on two cross coupled differential pairs positive feedback and switchable current sources, has a lower power dissipation, higher speed, less area, and it is shown to be very robust against transistor mismatch, noise immunity. Previous reported comparators are designed and simulated their DC response and Transient response in Cadence®Virtuoso Analog Design Environment using GPDK 90nm technology. Layouts of the proposed comparator have been done in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS has been checked and compared with the corresponding circuits and RC extracted diagram has been generated. After that post layout simulation with 1V supply voltage has been done and compared the speed, power dissipation, Area, delay with the results before layout and the superior features of the proposed comparator are established

  5. High-Speed Video Analysis of Damped Harmonic Motion

    Poonyawatpornkul, J.; Wattanakasiwich, P.

    2013-01-01

    In this paper, we acquire and analyse high-speed videos of a spring-mass system oscillating in glycerin at different temperatures. Three cases of damped harmonic oscillation are investigated and analysed by using high-speed video at a rate of 120 frames s[superscript -1] and Tracker Video Analysis (Tracker) software. We present empirical data for…

  6. Intelligent high-speed cutting database system development

    2008-01-01

    In this paper,the components of a high-speed cutting system are analyzed firstly.The component variables of the high-speed cutting system are classified into four types:uncontrolled variables,process variables,control variables,and output variables.The relationships and interactions of these variables are discussed.Then,by analyzing and comparing intelligent reasoning methods frequently used,the hybrid reasoning is employed to build the high-speed cutting database system.Then,the data structures of high-speed cutting case base and databases are determined.Finally,the component parts and working process of the high-speed cutting database system on the basis of hybrid reasoning are presented.

  7. Investigation of wear and tool life of coated carbide and cubic boron nitride cutting tools in high speed milling

    Twardowski, P.; Legutko, S.; Krolczyk, G.; Hloch, Sergej

    2015-01-01

    Roč. 7, č. 6 (2015), s. 1-9. ISSN 1687-8132 Institutional support: RVO:68145535 Keywords : hardened steel s * milling tools * high speed machining * tool life * wear Subject RIV: JQ - Machines ; Tools Impact factor: 0.575, year: 2014 http://ade.sagepub.com/content/7/6/1687814015590216.full.pdf+html

  8. The Paris - Strasbourg high-speed line; Hochgeschwindigkeitsstrecke Paris - Strassburg

    Brux, G.

    2007-07-01

    On 10th June 2007, TGV high-speed trains operated by French state railways SNCF, and ICE high-speed trains of Deutsche Bahn, will commence operations of France's eastern highspeed line Paris - Strasbourg, running services from Paris to Luxembourg, Frankfurt am Main and Stuttgart, and also to Basel and Zurich. As from the start of the new timetable on 9th December 2007, the service will also extend to Munich. The new high-speed line will shorten rail travels on these connections by several hours. (orig.)

  9. AN ANALYSIS METHOD FOR HIGH-SPEED CIRCUIT SYSTEMS

    2006-01-01

    A new method for analyzing high-speed circuit systems is presented. The method adds transmission line end currents to the circuit variables of the classical modified nodal approach. Then the matrix equation describing high-speed circuit system can be formulated directly and analyzed conveniently for its normative form. A time-domain analysis method for transmission lines is also introduced. The two methods are combined together to efficiently analyze high-speed circuit systems having general transmission lines. Numerical experiment is presented and the results are compared with that calculated by Hspice.

  10. Next Generation Modeling Technology for High Speed Rotorcraft Project

    National Aeronautics and Space Administration — Development of a new generation of high speed rotorcraft has been hampered by both an absence of strong predictive methods for rotors operating at very high advance...