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Operation of three parallel AN/AO processes to enrich denitrifying phosphorus removing bacteria for low strength wastewater treatment 被引量:6
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作者 XIA Si-qing LIU Hong-bo 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第3期433-438,共6页
Three parallel anaerobic-anoxic/anaerobic-aerobic (AN/AO) processes were developed to enrich denitrifying phosphorus removal bacteria (DPB) for low strength wastewater treatment. The main body of the parallel AN/A... Three parallel anaerobic-anoxic/anaerobic-aerobic (AN/AO) processes were developed to enrich denitrifying phosphorus removal bacteria (DPB) for low strength wastewater treatment. The main body of the parallel AN/AO process consists of an AN (anaerobic-anoxic) process and an AO (anaerobic-aerobic) process. In the AO process, the common phosphorus accumulating organisms (PAOs) was dominate, while in the AN process, DPB was dominate, The volume of anaerobic zone(Vana):anoxie zone(Vano) : aerobic zone (Vaer) for the parallel AN/AO process is 1:1:1 in contrast with a Vana:Vaer and Vano:Vaer of 1:2 and 1:4 for a traditional biological nutrient removal process (BNR). Process 3 excels in the 3 processes on the basis of COD, TN and TP removal. For 4 month operation, the effluent COD concentration of process 3 did not exceed 60 mg/L; the effluent TN concentration of process 3 was lower than 15 mg/L; and the effluent TP concentration of process 3 was lower than 1 mg/L. 展开更多
关键词 parallel AN/AO process denitrifying phosphorus removing bacteria (DPB) low strength wastewater biological nutrientremoval (BNR)
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MEASUREMENT OF K_(IC)OF MEDIAN OR LOW STRENGTH STEEL USING ROUND BARS WITH CIRCUMFERENCIAL CRACK
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作者 LIU Zaihua Huazhong University of Science and Technology,Wuhan,China ZHAO Dongli Bureau of Complete Sets of Equipment,State Machinery Commission,Beijing,China Dept.of Mechanics,Huazhong University of Science and Technology,Yujiashan,Wuhan,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1989年第3期201-207,共7页
The size effect of tension round bars with circumferential crack was described and used to measure the plane-strain fracture toughness K_(1c) of median or low strength steel.The size of cylindrical specimen required f... The size effect of tension round bars with circumferential crack was described and used to measure the plane-strain fracture toughness K_(1c) of median or low strength steel.The size of cylindrical specimen required for K_(1c) measurement is much smaller than that of standard specimen.The J-integral values of the cylindrical sqecimens were calculated to characterize the size effect.The finite element calculution and fracture morphology analysis have been conducted to eyplain the fact that smaller cylindrical specimen could be used to measure K_(1c) of median or low strength steel. 展开更多
关键词 median or low strength steel fracture touglmess round bar specimen
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Properties of Rapid Hardening Controlled Low Strength Material Made of Recycled Fine Aggregate from Urban Red Brick Construction Waste
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作者 Jin Ran Jinxi Zhang 《World Journal of Engineering and Technology》 2017年第2期188-197,共10页
In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardeni... In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardening controlled low strength material, which utilizes both rapid hardening sulphoaluminate cement and recycled fine aggregate from urban red brick construction waste. Totally, sixteen mixtures were prepared for the experiment with different cement-to-sand ratios and water-to-solid ratios. The flowability and bleeding rate of fresh mixture were measured to evaluate its workability, and the compressive strength of hardened mixture was tested to evaluate its rapid hardening and mechanical properties. Test results indicate that rapid hardening controlled low strength material containing recycled fine aggregate from urban red brick construction waste can achieve the desirable flowability, but the bleeding rate increases with the increase of flowability. In addition, 2-hour compressive strength can reach 0.08 - 0.12 MPa, and 4-hour compressive strength is 0.32 - 1.54 MPa, which can meet the requirements of emergency backfill construction. At last, based on the derived compressive strength, a fitting model for predicting compressive strength evolution of this new rapid hardening backfill material is developed, which fits accurately with these experimental data. 展开更多
关键词 CONTROLLED low strength MATERIAL Rapid Hardening SULPHOALUMINATE Cement Recycled Fine Aggregate Construction Waste URBAN Red Brick Workability Compressive strength
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Metabolic dysfunction-associated fatty liver disease and low muscle strength: A comment
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作者 Masood Muhammad Karim Amna Subhan Butt 《World Journal of Gastroenterology》 SCIE CAS 2024年第17期2371-2373,共3页
The diagnosis of non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease only on the basis of laboratory parameter score such as Hepatic Steatosis Index which includes liver en... The diagnosis of non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease only on the basis of laboratory parameter score such as Hepatic Steatosis Index which includes liver enzymes,gender,basal metabolic index,and presence of diabetic mellitus is not sufficient to exclude other causes of deranged liver enzymes especially medications and autoimmune related liver diseases.As the guideline suggests ultrasound is the preferred first-line diagnostic procedure for imaging of NAFLD,as it provides additional diagnostic information and the combination of biomarkers/scores and transient elastography might confer additional diagnostic accuracy and evident from previous similar studies too. 展开更多
关键词 Non-alcoholic fatty liver disease Metabolic dysfunction associated fatty liver disease low muscle strength Hepatic Steatosis Index Letter to the editor
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The Impact of the Inclusion of MgO Nano-Fillers in a Polyethylene Matrix on Dielectric Strength and Resistance to Partial Discharges
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作者 Virginie Griseri Dominique Mary +1 位作者 David Malec Eric David 《Open Journal of Applied Sciences》 2024年第3期626-634,共9页
One commonly used strategy to enhance polymers specific properties such as the resistance to partial discharges erosion is the incorporation into the polymeric matrix of inorganic micro or nanoparticles. This study fo... One commonly used strategy to enhance polymers specific properties such as the resistance to partial discharges erosion is the incorporation into the polymeric matrix of inorganic micro or nanoparticles. This study focused on the dielectric properties of Low-Density Polyethylene (LDPE) filled with nano-sized Magnesium Oxide (MgO) particles compounded by thermo-mechanical process and one of the purposes was to establish appropriate processing parameters in order to reach the desired dielectric properties. LDPE was used as a matrix and was reinforced by MgO particles having a nominal average size of 30 nm. The MgO nanoparticles were treated with a silane coupling agent (3-Glycidyloxypropyl Trimethoxysilane). The samples were initially prepared in a melt-mixing chamber with a MgO content of 1% wt. These pre-mixed samples were further treated by the means of thermo-mechanical mixing in a conical co-rotating twin-screw extruder in order to improve the dispersion and distribution of the MgO particles. In this report, both lifetime under a PD activity and AC dielectric strength of pure and nano-filled LDPE samples have been measured and compared. Nano-filled LDPE samples were found to exhibit an improve lifetime, without any detrimental impact on their short-term dielectric strength. This suggests that nano-filled LDPE may be for electric applications for which the dielectric materials may be exposed to partial discharge activities. This is significant result for the use of MgO-reinforced PE as an insulating material for HV cables since the resistance to PD is closely related to treeing resistance which is the main electrical degradation mechanism that leads to failure for shielded extruded power cables. 展开更多
关键词 low Density Polyethylene MgO Nanofillers Dielectric strength Partial Discharges Resistance
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Microstructure and mechanical properties of high-strength low alloy steel by wire and arc additive manufacturing 被引量:8
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作者 Yi-li Dai Sheng-fu Yu +1 位作者 An-guo Huang Yu-sheng Shi 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第7期933-942,共10页
A high-building multi-directional pipe joint(HBMDPJ)was fabricated by wire and arc additive manufacturing using high-strength low-alloy(HSLA)steel.The microstructure characteristics and transformation were observed an... A high-building multi-directional pipe joint(HBMDPJ)was fabricated by wire and arc additive manufacturing using high-strength low-alloy(HSLA)steel.The microstructure characteristics and transformation were observed and analyzed.The results show that the forming part includes four regions.The solidification zone solidifies as typical columnar crystals from a molten pool.The complete austenitizing zone forms from the solidification zone heated to a temperature greater than 1100℃,and the typical columnar crystals in this zone are difficult to observe.The partial austenitizing zone forms from the completely austenite zone heated between Ac1(austenite transition temperature)and1100℃,which is mainly equiaxed grains.After several thermal cycles,the partial austenitizing zone transforms to the tempering zone,which consistes of fully equiaxed grains.From the solidification zone to the tempering zone,the average grain size decreases from 75 to20μm.The mechanical properties of HBMDPJ satisfies the requirement for the intended application. 展开更多
关键词 wire and arc additive manufacturing high strength low alloy steel microstructure INCLUSIONS fine grain ferrite mechanical properties
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Numerical simulation of residual stress and deformation for submerged arc welding of Q690D high strength low alloy steel thick plate 被引量:7
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作者 Zhu Zikun Han Yang +2 位作者 Zhang Zhou Zhang Yi Zhou Longzao 《China Welding》 CAS 2021年第3期49-58,共10页
The finite element simulation software SYSWELD is used to numerically simulate the temperature field,residual stress field,and welding deformation of Q690D thick plate multi-layer and multi-pass welding under differen... The finite element simulation software SYSWELD is used to numerically simulate the temperature field,residual stress field,and welding deformation of Q690D thick plate multi-layer and multi-pass welding under different welding heat input and groove angles.The simulation results show that as the welding heat input increases,the peak temperature during the welding process is higher,and the residual stress increases,they are all between 330–340 MPa,and the residual stress is concentrated in the area near the weld.The hole-drilling method is used to measure the actual welding residual stress,and the measured data is in good agreement with the simulated value.The type of post-welding deformation is angular deformation,and as the welding heat input increases,the maximum deformation also increases.It shows smaller residual stress and deformation when the groove angle is 40°under the same heat input.In engineering applications,under the premise of guaranteeing welding quality,smaller heat input and 40°groove angle should be used. 展开更多
关键词 numerical simulation multi-layer and multi-pass welding Q690D high strength low alloy steel welding residual stress and deformation
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Low temperature impact strength of heavy section ductile iron castings:effects of microstructure and chemical composition 被引量:2
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作者 C.Labrecque P.M.Cabanne 《China Foundry》 SCIE CAS 2011年第1期66-73,共8页
A foundry research project has been recently initiated at RTIT in order to better understand the fabrication of as-cast heavy section DI parts meeting high impact energy requirements at low temperatures.The experiment... A foundry research project has been recently initiated at RTIT in order to better understand the fabrication of as-cast heavy section DI parts meeting high impact energy requirements at low temperatures.The experimental castings have the following dimensions 180 mm x 180 mm x 190 mm.The achieved as-cast Charpy impact strengths were as follows:17 J (RT),16 J (-20℃) and 11 J (-40℃).The foundry process,the chemical composition and the microstructure of this experimental casting are compared to the ones of various examples in order to show the detrimental effects of residual elements,microshrinkage and microcarbide on the impact properties.Finally,quality index empirical models (based on casting chemical compositions) are used to analyse the impact tests results.This paper illustrates that an adequate nodule count can contribute to reducing the detrimental effects of the residual elements and microsegregation. 展开更多
关键词 heavy section ductile iron casting as-cast microstructure low temperature impact strength quality index ferritic ductile iron
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Experiment Study on Self-stress of High-strength, Low-heat and Micro-expansion Concrete-filled Steel Tube 被引量:2
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作者 卢哲安 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2001年第2期83-86,共4页
The self-stress trial of the fifteen high-strength, low-heat andmicro-expansion concrete-filled steel tube(CFST)is introduced, andthe generating and distributing features of pre-stress and itsrelation to add- ing quan... The self-stress trial of the fifteen high-strength, low-heat andmicro-expansion concrete-filled steel tube(CFST)is introduced, andthe generating and distributing features of pre-stress and itsrelation to add- ing quantity of expansive agent, which providespersuasive dependences for optimal design of high-strength, low- heatand micro-expansion CFST were investigated, especially for the designof added quantity of expansive agent. 展开更多
关键词 HIGH-strength low-heat and micro-expansion CFST expansion agent
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Effect of Fast Cooling Rate on the Microstructure and Mechanical Properties of Low-Carbon High-Strength Steel Annealed in the Intercritical Region 被引量:3
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作者 李壮 田勇 +2 位作者 KANG Shaopu ZHENG Zhen LIU Ming 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第3期572-577,共6页
The effect of fast cooling rate on the microstructure and mechanical properties of low-carbon high-strength steel annealed in the intercritical region was investigated using a Gleeble 1500 thermomechanical simulator a... The effect of fast cooling rate on the microstructure and mechanical properties of low-carbon high-strength steel annealed in the intercritical region was investigated using a Gleeble 1500 thermomechanical simulator and a continuous annealing thermomeehanical simulator. The results showed that the microstructure consisted of ferrite and bainite as the main phases with a small amount of retained austenite and martensite islands at cooling rate of 5 and 50 ℃/s, respectively. Fast cooling after continuous annealing affected all constituents of the microstructure. The mechanical properties were improved considerably. Ultimate tensile strength (U-TS) increased and total elongation (TEL) decreased with increasing cooling rate in all specimens. The specimen 1 at a cooling rate of 5 ℃/s exhibited the maximum TEL and UTSxTEL (20% and 27 200 MPa%, respectively) because of the competition between weakening by presence of the retained austenite plus the carbon indigence by carbide precipitation, and strengthening by martensitic islands and precipitation. The maximum UTS and YS (1 450 and 951 MPa, respectively) were obtained for specimen 2 at a cooling rate of 50 ℃/s. This is attributed to the effect of dispersion strengthening of finer martensite islands and the effect of precipitation strengthening of carbide precipitates. 展开更多
关键词 cooling rate low-carbon high-strength steel intercritical annealing MICROSTRUCTURE mechanical properties
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Effect of microstructure variation on the corrosion behavior of high-strength low-alloy steel in 3.5wt% NaCl solution 被引量:3
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作者 Yu-bing Guo Chong Li +4 位作者 Yong-chang Liu Li-ming Yu Zong-qing Ma Chen-xi Liu Hui-jun Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第6期604-612,共9页
The effect of microstructure variation on the corrosion behavior of high-strength low-alloy(HSLA) steel was investigated. The protective property of the corrosion product layer was also explored. Experimental result... The effect of microstructure variation on the corrosion behavior of high-strength low-alloy(HSLA) steel was investigated. The protective property of the corrosion product layer was also explored. Experimental results reveal that the type of microstructure has significant effect on the corrosion resistance of HSLA steel. The measurement results of weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy indicate that the steel with acicular ferrite microstructure exhibits the lowest corrosion rate. Martensite exhibits a reduced corrosion resistance compared with polygonal ferrite. It is found that the surface of the acicular ferrite specimen uniformly covered by corrosion products is seemingly denser and more compact than those of the other two microstructures, and can provide some amount of protection to the steel; thus, the charge transfer resistance and modulus values of the acicular ferrite specimen are the largest. However, corrosion products on martensite and polygonal ferrite are generally loose, porous, and defective, and can provide minor protectiveness; thus, the charge transfer resistance values for polygonal ferrite and martensite are lower. 展开更多
关键词 high-strength low-alloy steel microstructure corrosion sodium chloride solutions
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Effect of welding processes on mechanical and microstructural characteristics of high strength low alloy naval grade steel joints 被引量:7
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作者 S.RAGU NATHAN V.BALASUBRAMANIAN +1 位作者 S.MALARVIZHI A.G.RAO 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2015年第3期308-317,共10页
Naval grade high strength low alloy(HSLA) steels can be easily welded by all types of fusion welding processes. However, fusion welding of these steels leads to the problems such as cold cracking, residual stress, dis... Naval grade high strength low alloy(HSLA) steels can be easily welded by all types of fusion welding processes. However, fusion welding of these steels leads to the problems such as cold cracking, residual stress, distortion and fatigue damage. These problems can be eliminated by solid state welding process such as friction stir welding(FSW). In this investigation, a comparative evaluation of mechanical(tensile, impact,hardness) properties and microstructural features of shielded metal arc(SMA), gas metal arc(GMA) and friction stir welded(FSW) naval grade HSLA steel joints was carried out. It was found that the use of FSW process eliminated the problems related to fusion welding processes and also resulted in the superior mechanical properties compared to GMA and SMA welded joints. 展开更多
关键词 低合金高强度钢 焊接工艺 钢接头 组织结构 力学性能 搅拌摩擦焊 机械特性 焊接方法
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Effect of microstructure on the low temperature toughness of high strength pipeline steels 被引量:10
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作者 Yan-ping Zeng Peng-yu Zhu Ke Tong 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第3期254-261,共8页
Microstructure observations and drop-weight tear test were performed to study the microstructures and mechanical properties of two kinds of industrial X70 and two kinds of industrial X80 grade pipeline steels. The eff... Microstructure observations and drop-weight tear test were performed to study the microstructures and mechanical properties of two kinds of industrial X70 and two kinds of industrial X80 grade pipeline steels. The effective grain size and the fraction of high angle grain boundaries in the pipeline steels were investigated by electron backscatter diffraction analysis. It is found that the low temperature toughness of the pipeline steels depends not only on the effective grain size, but also on other microstructural factors such as martensite-austenite (MA) constituents and precipitates. The morphology and size of MA constituents significantly affect the mechanical properties of the pipeline steels. Nubby MA constituents with large size have significant negative effects on the toughness, while smaller granular MA constituents have less harmful effects. Similarly, larger Ti-rich nitrides with sharp corners have a strongly negative effect on the toughness, while fine, spherical Nb-rich carbides have a less deleterious effect. The low temperature toughness of the steels is independent of the fraction of high angle grain boundaries. 展开更多
关键词 high strength pipe steels microstrucmre low temperature TOUGHNESS influencing factors
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Low temperature impact toughness of laser hybrid welded joint of high strength low alloy steel
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作者 倪加明 李铸国 +2 位作者 黄坚 倪慧峰 吴毅雄 《China Welding》 EI CAS 2011年第3期1-5,共5页
High strength low alloy steel with 16 mm thickness was welded by using high power laser hybrid welding. Microstrueture was characterized by using optical microscopy, scanning electron microscopy ( SEM ) , transmissi... High strength low alloy steel with 16 mm thickness was welded by using high power laser hybrid welding. Microstrueture was characterized by using optical microscopy, scanning electron microscopy ( SEM ) , transmission electron microscopy (TEM) and selected area electron diffraction (SAED). Low temperature impact toughness was estimated by using Charpy V-notch impact samples selected from the upper part and the lower part at the same heterogeneous joint. Results show that the low temperature impact absorbed energies of weld metal are (202,180,165 J) of upper samples and (178,145,160 J) of lower samples, respectively. All of them increase compared to base metal. The embrittlement of HAZ does not occur. Weld metal primarily consists of refined carbide free bainite and a little granular bainite since laser hybrid welding owns the character of low heat input. Retained austenite constituent film "locates among the lath structure of bainitie ferrite. Refined bainitic ferrite lath and retained austenite constituent film provide better low temperature impact toughness compared to base metal. 展开更多
关键词 laser hybrid welding high strength low alloy steel low temperature impact toughness carbide free bainite retained austenite constituent film
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Thermal Activation Analyses of Dynamic FractureToughness of High Strength Low Alloy Steels
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作者 Cunjian LI and Shaohua LI Welding Research Department, Central Iron & Steel Research Institute, Beijing 100081, China Yuqing DENG State Administration of Metallurgical Industry, Beijing 100711, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第2期215-218,共4页
A formula is derived for determining the influence of temperature and loading rate on dynamic fracture toughness of a high strength low alloy steel (HQ785C) from thermal activation analysis of the experimental results... A formula is derived for determining the influence of temperature and loading rate on dynamic fracture toughness of a high strength low alloy steel (HQ785C) from thermal activation analysis of the experimental results of three-point bend specimens as well as introducing an Arrhenius formula. It is shown that the results obtained by the given formula are in good agreement with the experimental ones in the thermal activation region. The present method is also valuable to describe the relationship between dynamic fracture toughness and temperature and loading rate of other high strength low alloy steels. 展开更多
关键词 TEST GB Thermal Activation Analyses of Dynamic FractureToughness of High strength low Alloy Steels
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Performances of the High Strength Low Heat Pump Concrete (HLPC) 被引量:1
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作者 张云升 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2002年第3期56-59,共4页
The effects of mineral admixtures on fluidity,mechanical and hydrational exothermic behavior were studied.The results show that,double adding ways,i e,fly ash and slag were added at the same time,not only improves th... The effects of mineral admixtures on fluidity,mechanical and hydrational exothermic behavior were studied.The results show that,double adding ways,i e,fly ash and slag were added at the same time,not only improves the fluidity of fresh concrete with low W/B and compensates the lower early compressive strength of harden concrete caused by high adding amount of fly ash, but also greatly reduces the highest temperature rise, exothermic rate and total heat liberation of 3 day of binder pastes in HLPC, and postponed the arrival time of the highest temperature rise. HLPC was prepared and applied to project practice successfully. 展开更多
关键词 mineral admixtures double adding ways high strength PUMP low hydration heat CONCRETE
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STUDY ON STRENGTH AND PETROGRAPHIC STRUCTURE OF CLINKER BY LOW-TEMPERATURE BURNING
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作者 郭俊才 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1995年第3期29-36,共8页
In this paper,the strength and petrographic structure of clinker by low-temperature burning are studied. The results show that both the calcining temperature of Ca-CO3 and sintering temperature clinker decreases by 15... In this paper,the strength and petrographic structure of clinker by low-temperature burning are studied. The results show that both the calcining temperature of Ca-CO3 and sintering temperature clinker decreases by 150 degrees C compared with those in traditional rotary kiln,the rate of f-CaO in the clinker sintered at 1300 degrees C is 0.29% similar to 2.81%, the strength of the clinker is 62. 5MPa with maximum 69. 4MPa at a specific area of 2900 similar to 3400cm(2)/g. The results also show that the types of petrographic structure of the clinker can be classified as: homogeneous structure, inlaid or edged structure,stain-melting structure and porous structure. The clinker sintered at 1300 +/- 15 degrees C temperature and with enough retention period is mainly in homogeneous structure. 展开更多
关键词 low-temperature sintering clinker strength petrographic structure of clinker
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Effects of [S] and T[O] on strength and toughness of high purification low alloy steel plates
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作者 ZengwuZhao XinhuaWang GuoweiChang 《Journal of University of Science and Technology Beijing》 CSCD 2003年第5期27-30,共4页
The effect of [S] on strength and toughness of low alloy steel plates inwhich sum of [P], [N], T[O] is less than 8x10^(-5) and the effect of T[O] on strength and toughnessof the steel plates in which sum of [S], [P], ... The effect of [S] on strength and toughness of low alloy steel plates inwhich sum of [P], [N], T[O] is less than 8x10^(-5) and the effect of T[O] on strength and toughnessof the steel plates in which sum of [S], [P], [N] is less than 7x10^(-5) were investigated. It isfound that the strength of the steel plates decreases with increasing [S] content when [S] is lessthan 4x10^(-5). When [S] varies within the range of 4x10^(-5)-1.2x10^(-4), [S] has no significanteffect on strength of the steel. The strength of the steel plates increases with increasing T[O]content when T[O] is less than 30x10^(-6), but decreases with increasing T[O] when T[O] is more than3x10^(-5). The difference between the LETT in plate length direction and LETT in width directiondecreases with decreasing [S] content. However, even when [S] is decreased to 9x10^(-6), thedifference of the LETT is still 16℃. When T[O] varies between 1.8x10^(-5) and 5.2x10^(-5), the lowtemperature impact toughness of the steel plates slowly decreases with T[O] increasing. When T[O]increases to more than 5.2x10^(-5), the low temperature toughness of the steel rapidly decreaseswith increasing T[O] content. 展开更多
关键词 low alloy steel strength TOUGHNESS SULFUR oxygen tough-brittle transfertemperature (LETT)
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Effects of low temperatures on strength and power input into rock failure 被引量:1
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作者 Evgenii V.Zakharov Alexander S.Kurilko 《Research in Cold and Arid Regions》 CSCD 2014年第5期455-460,共6页
Study results of low temperature effects on the strength index and specific power input into rock failure are presented.It has been experimentally determined that within the range of-5 °С to-15 °С,there is... Study results of low temperature effects on the strength index and specific power input into rock failure are presented.It has been experimentally determined that within the range of-5 °С to-15 °С,there is a local minimum at which the compression strength and specific power input into failure of some rocks are 10%-50% lower than those at positive temperatures. 展开更多
关键词 strength power input into failure low temperatures carbonate rocks KIMBERLITE POROSITY
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Low cycle fatigue behavior of high strength gun steels
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作者 Maoqiu Wang Han Dong +1 位作者 Qi Wang Changgang Fan Division of Structural Materials, Central Iron & Steel Research Institute, Beijing 100081, China 《Journal of University of Science and Technology Beijing》 CSCD 2004年第3期268-272,共5页
The low cycle fatigue (LCF) behavior of two high strength steels, withnominal chemical compositions (mass fraction, %) of 0.40C-1.5Cr-3Ni-0.4Mo-0.2V (PCrNi3MoV) and0.25C-3Cr-3Mo-0.8Ni-0.1Nb (25Cr3Mo3NiNb), was investi... The low cycle fatigue (LCF) behavior of two high strength steels, withnominal chemical compositions (mass fraction, %) of 0.40C-1.5Cr-3Ni-0.4Mo-0.2V (PCrNi3MoV) and0.25C-3Cr-3Mo-0.8Ni-0.1Nb (25Cr3Mo3NiNb), was investigated by using the smooth bar specimenssubjected to strained-controlled push-pull loading. It is found that both steels show cyclicsoftening, but 25Cr3Mo3NiNb steel has a lower tendency to cyclic softening. 25Cr3Mo3NiNb steel hashigher fatigue ductility, and its transition fatigue life is almost three times that of PCrNi3MoV.25Cr3Mo3NiNb steel also shows higher LCF life either at a given total strain amplitude above 0.5% orat any given plastic strain amplitude, despite its lower monotonic tensile strength than that ofPCrNi3MoV. It also means that 25Cr3Mo3NiNb steel can endure higher total strain amplitude andplastic strain amplitude at a given number of reversals to failure within 10~4. 25Cr3Mo3NiNb steelis expected to be a good gun steel with high LCF properties because only several thousand firingsare required for gun barrel in most cases. 展开更多
关键词 high strength steel low cycle fatigue mechanical property
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