Ultra-deep reservoirs play an important role at present in fossil energy exploitation.Due to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do ...Ultra-deep reservoirs play an important role at present in fossil energy exploitation.Due to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do not produce satisfactory results when conventional fracturing fluids with a low pumping rate are used.In response to the above problem,a fracturing fluid with a density of 1.2~1.4 g/cm^(3)was developed by using Potassium formatted,hydroxypropyl guanidine gum and zirconium crosslinking agents.The fracturing fluid was tested and its ability to maintain a viscosity of 100 mPa.s over more than 60 min was verified under a shear rate of 1701/s and at a temperature of 175℃.This fluid has good sand-carrying performances,a low viscosity after breaking the rubber,and the residue content is less than 200 mg/L.Compared with ordinary reconstruction fluid,it can increase the density by 30%~40%and reduce the wellhead pressure of 8000 m level reconstruction wells.Moreover,the new fracturing fluid can significantly mitigate safety risks.展开更多
Three high-temperature resistant polymeric additives for water-based drilling fluids are designed and developed:weakly cross-linked zwitterionic polymer fluid loss reducer(WCZ),flexible polymer microsphere nano-pluggi...Three high-temperature resistant polymeric additives for water-based drilling fluids are designed and developed:weakly cross-linked zwitterionic polymer fluid loss reducer(WCZ),flexible polymer microsphere nano-plugging agent(FPM)and comb-structure polymeric lubricant(CSP).A high-temperature resistant and high-density polymeric saturated brine-based drilling fluid was developed for deep drilling.The WCZ has a good anti-polyelectrolyte effect and exhibits the API fluid loss less than 8 mL after aging in saturated salt environment at 200°C.The FPM can reduce the fluid loss by improving the quality of the mud cake and has a good plugging effect on nano-scale pores/fractures.The CSP,with a weight average molecular weight of 4804,has multiple polar adsorption sites and exhibits excellent lubricating performance under high temperature and high salt conditions.The developed drilling fluid system with a density of 2.0 g/cm^(3)has good rheological properties.It shows a fluid loss less than 15 mL at 200°C and high pressure,a sedimentation factor(SF)smaller than 0.52 after standing at high temperature for 5 d,and a rolling recovery of hydratable drill cuttings similar to oil-based drilling fluid.Besides,it has good plugging and lubricating performance.展开更多
To further improve the oxidation-resistance of materials and reduce the cost of grid plates in grate-kiln, a new kind of heat-resistant grid plate was developed. The microstructure of this grid plate with a life more ...To further improve the oxidation-resistance of materials and reduce the cost of grid plates in grate-kiln, a new kind of heat-resistant grid plate was developed. The microstructure of this grid plate with a life more than 18 months was studied by XRD, SEM and EDS techniques. The results show that high hardness, high intensity and good impact property make the new kind of heat-resistant grid plate and its oxide film have a higher resistance to deformation and abrasion at 900-1000℃ Besides, small grain size is beneficial to form a complete protective oxide film. The oxide film composed of SiO2 layer, Cr2O3 layer and Fe2O3 layer is rather thin and bonds closely with the backing. The forming of the chemical stable nickel-rich layer increases the density of Cr2O3 layer.展开更多
In this paper the alkali-activated slag cementitious materials(AASCM)which strength at 600 ℃ is larger than that of AASCM at room temperature,were prepared to paste CFRP sheets to strengthen four simply supported unb...In this paper the alkali-activated slag cementitious materials(AASCM)which strength at 600 ℃ is larger than that of AASCM at room temperature,were prepared to paste CFRP sheets to strengthen four simply supported unbonded prestressed composite beams encased circular steel tube truss after ultimate limit state.Test on flexural behavior of these four beams was performed.Moreover,normal section load-bearing capacity of these beams and the curve load-deflection at mid-span were obtained.Experimental results show that it is feasible to strengthen concrete members with CFRP sheets bonded with AASCM.Based on the experimental results and theoretical study,computational method of stiffness is proposed for calculating bending rigidity and normal section load-bearing capacity of concrete simply supported beams strengthened with CFRP sheets bonded with AASCM.Formula of bending rigidity calculation was founded which results are in good agreement with testing data.展开更多
The kinetic curves of the high-temperature oxidation of austenitic heat resistant stainless steel 1. 4828 at 1 050 ℃ were measured using a weighing method. It is shown that the oxidation curves at 1 050 ℃ followed t...The kinetic curves of the high-temperature oxidation of austenitic heat resistant stainless steel 1. 4828 at 1 050 ℃ were measured using a weighing method. It is shown that the oxidation curves at 1 050 ℃ followed the parabolic line law, and after 250 h of oxidation, the mass gain was about 80 g/m2. The surface morphology and structure of the oxide layers were studied by scanning electron microscopy and X-ray diffraction. A complicated oxide layer obtained at 1 050 ℃ was mainly composed, from inner to outer, of (FeSi) 3 04, Cr2 03, Fe2 03, and spinel oxides FeCr204 and NiMn204.展开更多
Organic epoxy matrices have been widely used in the FRP reinforcing technique, but they have serious disadvantages of poor high-temperature resistance. An inorganic adhesive is invented to replace the organic adhesive...Organic epoxy matrices have been widely used in the FRP reinforcing technique, but they have serious disadvantages of poor high-temperature resistance. An inorganic adhesive is invented to replace the organic adhesive. For the inorganic adhesive at normal temperature and different high temperatures, the microstructure and phase composition are investigated by means of X-ray diffraction (XRD) and SEM respectively. Results show that inorganic adhesive can resist at least 600 ℃ high temperature. Fire-resistance performance of inorganic adhesive can meet the requirements of fiber reinforced polymer (FRP) strengthened RC structures.展开更多
Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a severe foliar disease of common wheat (Triticum aestivum L.) in the world. Resistance is the best approach to control the disease. Th...Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a severe foliar disease of common wheat (Triticum aestivum L.) in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene(s) for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 (M169). Seedlings of the parents, and F 1 , F 2 and F 2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat (SSR) techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F 2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.展开更多
High-temperature circulating fans blow 800 ℃ HN protective atmosphere to the surface of the strip as a jet heating power source or suspending source,playing a core role in metal strip continuous annealing furnaces. I...High-temperature circulating fans blow 800 ℃ HN protective atmosphere to the surface of the strip as a jet heating power source or suspending source,playing a core role in metal strip continuous annealing furnaces. In this study,several high-temperature alloys were experimentally compared based on their high-temperature mechanical properties,high-temperature creep resistance,and high-temperature oxidation resistance. The results indicate that though the price of HR-120 alloy is only half of Inconel 601,it is suitable for the manufacture of fans that can withstand a high temperature of 800 ℃ given its good creep resistance,high-temperature oxidation resistance,and price advantage.展开更多
Conventional MgO-C bricks(graphite content>14 wt.%)produce a great deal of greenhouse gas emission,while low-carbon MgO-C bricks have serious thermal shock resistance during high-temperature service.To enhance the ...Conventional MgO-C bricks(graphite content>14 wt.%)produce a great deal of greenhouse gas emission,while low-carbon MgO-C bricks have serious thermal shock resistance during high-temperature service.To enhance the high-temperature mechanical property and thermal shock resistance of low-carbon MgO-C bricks,a novel route of introducing ZrSiO_(4) powder into low-carbon MgO-C bricks was reported in such refractories with 2 wt.% flaky graphite.The results indicate that the low-carbon MgO-C brick with 0.5 wt.%ZrSiO_(4) addition has the maximum hot modulus of rupture at 1400℃ and the corresponding specimen fired in the carbon embedded atmosphere has the maximum residual strength ratio(98.6%)after three thermal shock cycles.It is found that some needle-like AlON and plate-like Al_(2)O_(3)-ZrO_(2) composites were in situ formed in the matrices after the low-carbon MgO-C bricks were coked at 1400℃,which can enhance the high-temperature mechanical property and thermal shock resistance due to the effect of fiber toughening and particle toughening.Moreover,CO_(2) emission of the newly developed low-carbon MgO-C bricks is reduced by 58.3% per ton steel after using them as the working lining of a 90 t vacuum oxygen decarburization ladle.展开更多
FeAl intermetallic compound with different contents of rare earth oxide La2O3 addition was prepared by hot pressing the mechanically alloyed powders.Effect of La2O3 on microstructure and high-temperature wear property...FeAl intermetallic compound with different contents of rare earth oxide La2O3 addition was prepared by hot pressing the mechanically alloyed powders.Effect of La2O3 on microstructure and high-temperature wear property of the sintered FeAl samples was investigated in this paper.The results showed that 1 wt.% La2O3 addition could refine the microstructure and increase the density of the FeAl intermetallic compound,and correspondingly improved the high-temperature wear resistance.SEM and EDS analyses of the wo...展开更多
High-temperature performance tests of chromium-containing stuffing sand for a steel ladle w ith different ratios w ere performed. A high-temperature simulation test furnace w as used to analyze the influence of the co...High-temperature performance tests of chromium-containing stuffing sand for a steel ladle w ith different ratios w ere performed. A high-temperature simulation test furnace w as used to analyze the influence of the composition ratio of ladle filler sand and sintering time on the high-temperature compression resistance of chromium-containing stuffing sand in the temperature range of 1 500- 1 600 ℃. The results show that the refractoriness of ladle filler sand w as the low est( only 1 610 ℃) w hen the composition ratio of chromite sand and silica sand w as 6∶ 4. M oreover,the high-temperature compression resistance w as high w hen the content of chromite sand w as at 70%; the resistance increased w ith increasing sintering time. When the sintering time w as extended at a temperature of 1 600 ℃,the high-temperature compression resistance of ladle filler sand first increased and then decreased after being overburnt.展开更多
Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testin...Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testing techniques.The experimental results indicate that sample A3(bauxite/kaolin ratio of 5:5)sintered at 1620℃has the optimum comprehensive properties,with bulk density of 2.83 g·cm^(-3)and bending strength of 155.44 MPa.After 30 thermal shocks(1000℃-room temperature,air cooling),the bending strength of sample A3 increases to 166.15 MPa with an enhancement rate of 6.89%,the corresponding thermal conductivity and specific heat capacity are 3.54 W·(m·K)^(-1)and 1.39 kJ·(kg·K)^(-1)at 800℃,and the thermal storage density is 1096 kJ·kg^(-1)(25-800 mullite ceramics;sintering properties;high-temperature thermal storage;thermal shock resistance).Mullite forms a dense and continuous interlaced network microstructure,which endows the samples high thermal storage density and high bending strength,but the decrease of bauxite/kaolin ratio leads to the decrease of mullite content,which reduces the properties of the samples.展开更多
Exhaust emission regulations of the automotive are enforced in each country to prevent air pollution and global warming,and the restriction standard tends to become severer.Various techniques such as the combustion im...Exhaust emission regulations of the automotive are enforced in each country to prevent air pollution and global warming,and the restriction standard tends to become severer.Various techniques such as the combustion improvement of gasoline,upgrades of the catalyst,and the thermal capacity decreases in the exhaust lines are adopted to suit the regulations,and these lead to an increase of the maximum temperature of the exhaust gas. Recently,ferritic stainless steels are mainly used to parts of exhaust lines,as their thermal expansion coefficient is small,and the cyclic oxidation resistance and the thermal fatigue property are better than austenitic stainless steels. This paper presents newly developed heat-resistant stainless steels from Nisshin Steel for exhaust lines usage,and describes the currents of the steel development that could be envisaged in the future.With regard to improving the high-temperature strength of ferritic stainless steels,the addition of Nb,Mo and Cu is effective in solution hardening and precipitation hardening at 700℃,while the addition of Nb,Mo and W is effective in mainly solution hardening at 900℃.The addition of Cr,Si and Mn suppress the breakaway oxidation in air at 950℃up to 200 h of ferritic stainless steels containing 14%Cr.Especially,the addition of 0.8%or higher Mn would effectively improve the adherence of oxide scale.It is confirmed that ferritic stainless steels,NSSHR-1(14Cr-lMn-0.9Si-Nb) and NSSHR-2(10Cr-0.9Si-Nb-Ti ),is having a superior heat resistance,formability and cost performance compared to conventional Type441 and Type439 respectively.展开更多
To solve the problem of the severe mismatch between the product and roll materials in the preliminary rolling line,a new graphitic steel material was designed,its microstructure and high-temperature friction and wear ...To solve the problem of the severe mismatch between the product and roll materials in the preliminary rolling line,a new graphitic steel material was designed,its microstructure and high-temperature friction and wear properties were investigated.Moreover,the feasibility of replacing semi-steel with this new material in the V1 stand roll was studied herein.The results show that the graphitic steel matrix is strengthened by silicon and nickel elements.The presence of spherical graphite also provides self-lubrication and heat conduction and prevents the propagation of cracks.Carbides in the appropriate amount and size strengthen the matrix,reduce the cracking effect of the matrix,and are not easily broken,thereby reducing high-temperature abrasive wear.Under the same hightemperature friction and wear conditions,compared with semi-steel,the wear-scar surface of graphitic steel exhibits less wear-scar depth and wear volume,a smaller friction coefficient,reduced oxide layer thickness,and fewer instances of peeling and microcracks.Therefore,the newly designed graphitic steel has higher wear resistance and hot-crack resistance than semi-steel,which makes it feasible for use in replacing semi-steel as a new V1 frame roll material in the blooming mill.展开更多
In order to realize the large-scale and high-value utilization of waste architectural ceramics,high-temperature resistant materials based on waste architectural ceramics were prepared with sodium silicate as the binde...In order to realize the large-scale and high-value utilization of waste architectural ceramics,high-temperature resistant materials based on waste architectural ceramics were prepared with sodium silicate as the binder,clay/bauxite and metakaolin/bauxite as coating materials,and the cold strength obtaining mechanism was explored.The phase composition,the microstructure and the mechanical properties of the high temperature resistant materials based on waste architectural ceramics were tested and analyzed.The results showed that when the heat treatment temperature was between 110-1000℃,the strength of the samples mainly came from the physical adhesion of sodium silicate and fine powder.When the temperature rose to 1100℃,the strength of the sample was improved since the internal low-melting-point components melted and promoted sintering.The addition of clay and bauxite can effectively enhance the flexural strength of the samples when the heat treatment temperature is 1000℃.When the heat treatment temperature rises from 900 to 1000℃,the flexural strength of the samples will be enhanced owing to the formation of silica alumina spinel and mullite from metakaolin.展开更多
Poly(diethyl fumarate-co-methoxyethyl acrylate-co-vinyl chloroacetate)(PDEFMV),a novel bio-based elastomer with a saturated structure,was synthesized via redox emulsion polymerization.The glass-transition temperatures...Poly(diethyl fumarate-co-methoxyethyl acrylate-co-vinyl chloroacetate)(PDEFMV),a novel bio-based elastomer with a saturated structure,was synthesized via redox emulsion polymerization.The glass-transition temperatures of PDEFMV,adjusted through the variation of the diethyl fumarate-to-methoxyethyl acrylate feeding ratio,ranged from-36.1 to-14.8 ℃.The number-average molecular weights of PDEFMV ranged from 384,000 to 46,000 g/mol.In designing the molecular structure,vinyl chloroacetate was used to provide active sites for subsequent vulcanization and crosslinking.The active chlorine groups within the PDEFMV chain reacted with the crosslinking agent trithiocyanuric acid under high temperature and pressure to form a nonsulfur crosslinked three-dimensional network structure.To achieve the desired properties,carbon black(CB,N330) was incorporated to reinforce PDEFMV,leading to the formation of PDEFMV/CB composites.A comprehensive study was conducted on the high-temperature oil resistance of PDEFMV/CB composites.Following immersion in IRM903 oil at temperatures of 150 and 200 ℃ for 72 h,the mass and volume changes in PDEFMV/CB were lower than those observed in commercially available acrylate rubber(AR)/CB,indicating that PDEFMV exhibited superior oil resistance.Furthermore,the aging characteristics and mechanisms of oil resistance in the PDEFMV/CB and AR/CB composites were investigated at different temperatures(150,200,and 250 ℃).The results provide insights into the operational temperature ranges suitable for PDEFMV/CB and offer valuable guidance for potential industrial applications.展开更多
Conformance control and water plugging are a widely used EOR method in mature oilfields.However,majority of conformance control and water plugging agents are unavoidable dehydrated situation in high-temperature and hi...Conformance control and water plugging are a widely used EOR method in mature oilfields.However,majority of conformance control and water plugging agents are unavoidable dehydrated situation in high-temperature and high-salinity low permeability reservoirs.Consequently,a novel conformance control system HPF-Co gel,based on high-temperature stabilizer(CoCl_(2)·H_(2)O,CCH)is developed.The HPF-Co bulk gel has better performances with high temperature(120℃)and high salinity(1×10^(5)mg/L).According to Sydansk coding system,the gel strength of HPF-Co with CCH is increased to code G.The dehydration rate of HPF-Co gel is 32.0%after aging for 150 d at 120℃,showing excellent thermal stability.The rheological properties of HPF gel and HPF-Co gel are also studied.The results show that the storage modulus(G′)of HPF-Co gel is always greater than that of HPF gel.The effect of CCH on the microstructure of the gel is studied.The results show that the HPF-Co gel with CCH has a denser gel network,and the diameter of the three-dimensional network skeleton is 1.5-3.5μm.After 90 d of aging,HPF-Co gel still has a good three-dimensional structure.Infrared spectroscopy results show that CCH forms coordination bonds with N and O atoms in the gel amide group,which can suppress the vibration of cross-linked sites and improve the stability at high temperature.Fractured core plugging test determines the optimized polymer gel injection strategy and injection velocity with HPF-Co bulk gel system,plugging rate exceeding 98%.Moreover,the results of subsequent waterflooding recovery can be improved by 17%.展开更多
Multifunctional,wearable,and durable textiles integrated with smart electronics have attracted tremendous attention.However,it remains a great challenge to balance new functionalities with high-temperature stability.H...Multifunctional,wearable,and durable textiles integrated with smart electronics have attracted tremendous attention.However,it remains a great challenge to balance new functionalities with high-temperature stability.Herein,textile-based pressure sensors with excellent electromagnetic interference(EMI)shielding,Joule heating,and high-temperature resistance were fabricated by constructing graphene/SiC(G/SiC)heterostructures on carbon cloth via laser chemical vapor deposition(LCVD).The resultant textiles exhibited excellent EMI efficiency of 74.2 dB with a thickness of 0.45 mm,Joule heating performance within a low working voltage(V)range of 1-3 V,and fast response time within 20 s.These properties arose from multiple reflections,interfacial polarization,and high conductivity due to the numerous amounts of nanoscale G/SiC heterostructures.More importantly,G/SiC/carbon fibers(CFs)demonstrated well high-temperature resistance with a heat resistance index(THri)of 380.2 C owing to the protection of a coating layer on the CFs upon oxidation.Meanwhile,the G/SiC/CFs presented good pressure-sensing performance with high sensitivity(S)of 52.93 kPal,fast response time of 85 ms,and a wide pressure range of up to 186 kPa.These features imply the potential of the G/SiC/CFs as efficient EMI shielding,electrical heater,and piezoresistive sensor textiles.展开更多
文摘Ultra-deep reservoirs play an important role at present in fossil energy exploitation.Due to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do not produce satisfactory results when conventional fracturing fluids with a low pumping rate are used.In response to the above problem,a fracturing fluid with a density of 1.2~1.4 g/cm^(3)was developed by using Potassium formatted,hydroxypropyl guanidine gum and zirconium crosslinking agents.The fracturing fluid was tested and its ability to maintain a viscosity of 100 mPa.s over more than 60 min was verified under a shear rate of 1701/s and at a temperature of 175℃.This fluid has good sand-carrying performances,a low viscosity after breaking the rubber,and the residue content is less than 200 mg/L.Compared with ordinary reconstruction fluid,it can increase the density by 30%~40%and reduce the wellhead pressure of 8000 m level reconstruction wells.Moreover,the new fracturing fluid can significantly mitigate safety risks.
基金Supported by the National Natural Science Foundation of China(52288101).
文摘Three high-temperature resistant polymeric additives for water-based drilling fluids are designed and developed:weakly cross-linked zwitterionic polymer fluid loss reducer(WCZ),flexible polymer microsphere nano-plugging agent(FPM)and comb-structure polymeric lubricant(CSP).A high-temperature resistant and high-density polymeric saturated brine-based drilling fluid was developed for deep drilling.The WCZ has a good anti-polyelectrolyte effect and exhibits the API fluid loss less than 8 mL after aging in saturated salt environment at 200°C.The FPM can reduce the fluid loss by improving the quality of the mud cake and has a good plugging effect on nano-scale pores/fractures.The CSP,with a weight average molecular weight of 4804,has multiple polar adsorption sites and exhibits excellent lubricating performance under high temperature and high salt conditions.The developed drilling fluid system with a density of 2.0 g/cm^(3)has good rheological properties.It shows a fluid loss less than 15 mL at 200°C and high pressure,a sedimentation factor(SF)smaller than 0.52 after standing at high temperature for 5 d,and a rolling recovery of hydratable drill cuttings similar to oil-based drilling fluid.Besides,it has good plugging and lubricating performance.
文摘To further improve the oxidation-resistance of materials and reduce the cost of grid plates in grate-kiln, a new kind of heat-resistant grid plate was developed. The microstructure of this grid plate with a life more than 18 months was studied by XRD, SEM and EDS techniques. The results show that high hardness, high intensity and good impact property make the new kind of heat-resistant grid plate and its oxide film have a higher resistance to deformation and abrasion at 900-1000℃ Besides, small grain size is beneficial to form a complete protective oxide film. The oxide film composed of SiO2 layer, Cr2O3 layer and Fe2O3 layer is rather thin and bonds closely with the backing. The forming of the chemical stable nickel-rich layer increases the density of Cr2O3 layer.
基金Sponsored by the Changjiang Scholars Program of China(Grant No.2009-37)the National Natural Science Foundation of China(Grant No.50678050)
文摘In this paper the alkali-activated slag cementitious materials(AASCM)which strength at 600 ℃ is larger than that of AASCM at room temperature,were prepared to paste CFRP sheets to strengthen four simply supported unbonded prestressed composite beams encased circular steel tube truss after ultimate limit state.Test on flexural behavior of these four beams was performed.Moreover,normal section load-bearing capacity of these beams and the curve load-deflection at mid-span were obtained.Experimental results show that it is feasible to strengthen concrete members with CFRP sheets bonded with AASCM.Based on the experimental results and theoretical study,computational method of stiffness is proposed for calculating bending rigidity and normal section load-bearing capacity of concrete simply supported beams strengthened with CFRP sheets bonded with AASCM.Formula of bending rigidity calculation was founded which results are in good agreement with testing data.
文摘The kinetic curves of the high-temperature oxidation of austenitic heat resistant stainless steel 1. 4828 at 1 050 ℃ were measured using a weighing method. It is shown that the oxidation curves at 1 050 ℃ followed the parabolic line law, and after 250 h of oxidation, the mass gain was about 80 g/m2. The surface morphology and structure of the oxide layers were studied by scanning electron microscopy and X-ray diffraction. A complicated oxide layer obtained at 1 050 ℃ was mainly composed, from inner to outer, of (FeSi) 3 04, Cr2 03, Fe2 03, and spinel oxides FeCr204 and NiMn204.
基金Funded by the National Natural Science Foundation of China(No.50678050)
文摘Organic epoxy matrices have been widely used in the FRP reinforcing technique, but they have serious disadvantages of poor high-temperature resistance. An inorganic adhesive is invented to replace the organic adhesive. For the inorganic adhesive at normal temperature and different high temperatures, the microstructure and phase composition are investigated by means of X-ray diffraction (XRD) and SEM respectively. Results show that inorganic adhesive can resist at least 600 ℃ high temperature. Fire-resistance performance of inorganic adhesive can meet the requirements of fiber reinforced polymer (FRP) strengthened RC structures.
基金support of the 111 Project from the Ministryof Education of China(B07049)the Key Technologies R&D Program of China during the 11th Five-Year Plan period(2006BAD08A05)the project of Toxicity Variation of Wheat Stripe Rust Pathogen and Demonstration of Integrated Management of Stripe Rust,China(200903035-02)are thankfully acknowledged
文摘Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a severe foliar disease of common wheat (Triticum aestivum L.) in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene(s) for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 (M169). Seedlings of the parents, and F 1 , F 2 and F 2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat (SSR) techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F 2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.
文摘High-temperature circulating fans blow 800 ℃ HN protective atmosphere to the surface of the strip as a jet heating power source or suspending source,playing a core role in metal strip continuous annealing furnaces. In this study,several high-temperature alloys were experimentally compared based on their high-temperature mechanical properties,high-temperature creep resistance,and high-temperature oxidation resistance. The results indicate that though the price of HR-120 alloy is only half of Inconel 601,it is suitable for the manufacture of fans that can withstand a high temperature of 800 ℃ given its good creep resistance,high-temperature oxidation resistance,and price advantage.
基金Enterprise Research and Development Project of Beijing Lirr High-Temperature Materials Co.,Ltd.(2020-02)Key Scientific Research Project for Universities and Colleges in Henan Province(19A430028)+1 种基金the Excellent Youth Research Project of Anhui Province(2022AH030135)the PhD Research Funding of Suzhou University(2021BSK041).
文摘Conventional MgO-C bricks(graphite content>14 wt.%)produce a great deal of greenhouse gas emission,while low-carbon MgO-C bricks have serious thermal shock resistance during high-temperature service.To enhance the high-temperature mechanical property and thermal shock resistance of low-carbon MgO-C bricks,a novel route of introducing ZrSiO_(4) powder into low-carbon MgO-C bricks was reported in such refractories with 2 wt.% flaky graphite.The results indicate that the low-carbon MgO-C brick with 0.5 wt.%ZrSiO_(4) addition has the maximum hot modulus of rupture at 1400℃ and the corresponding specimen fired in the carbon embedded atmosphere has the maximum residual strength ratio(98.6%)after three thermal shock cycles.It is found that some needle-like AlON and plate-like Al_(2)O_(3)-ZrO_(2) composites were in situ formed in the matrices after the low-carbon MgO-C bricks were coked at 1400℃,which can enhance the high-temperature mechanical property and thermal shock resistance due to the effect of fiber toughening and particle toughening.Moreover,CO_(2) emission of the newly developed low-carbon MgO-C bricks is reduced by 58.3% per ton steel after using them as the working lining of a 90 t vacuum oxygen decarburization ladle.
基金supported by the National Natural Science Foundation of China (50575034)
文摘FeAl intermetallic compound with different contents of rare earth oxide La2O3 addition was prepared by hot pressing the mechanically alloyed powders.Effect of La2O3 on microstructure and high-temperature wear property of the sintered FeAl samples was investigated in this paper.The results showed that 1 wt.% La2O3 addition could refine the microstructure and increase the density of the FeAl intermetallic compound,and correspondingly improved the high-temperature wear resistance.SEM and EDS analyses of the wo...
文摘High-temperature performance tests of chromium-containing stuffing sand for a steel ladle w ith different ratios w ere performed. A high-temperature simulation test furnace w as used to analyze the influence of the composition ratio of ladle filler sand and sintering time on the high-temperature compression resistance of chromium-containing stuffing sand in the temperature range of 1 500- 1 600 ℃. The results show that the refractoriness of ladle filler sand w as the low est( only 1 610 ℃) w hen the composition ratio of chromite sand and silica sand w as 6∶ 4. M oreover,the high-temperature compression resistance w as high w hen the content of chromite sand w as at 70%; the resistance increased w ith increasing sintering time. When the sintering time w as extended at a temperature of 1 600 ℃,the high-temperature compression resistance of ladle filler sand first increased and then decreased after being overburnt.
基金Funded by the National Key Research and Development Program of Science and Technology of China(No.2018YFB1501002)。
文摘Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testing techniques.The experimental results indicate that sample A3(bauxite/kaolin ratio of 5:5)sintered at 1620℃has the optimum comprehensive properties,with bulk density of 2.83 g·cm^(-3)and bending strength of 155.44 MPa.After 30 thermal shocks(1000℃-room temperature,air cooling),the bending strength of sample A3 increases to 166.15 MPa with an enhancement rate of 6.89%,the corresponding thermal conductivity and specific heat capacity are 3.54 W·(m·K)^(-1)and 1.39 kJ·(kg·K)^(-1)at 800℃,and the thermal storage density is 1096 kJ·kg^(-1)(25-800 mullite ceramics;sintering properties;high-temperature thermal storage;thermal shock resistance).Mullite forms a dense and continuous interlaced network microstructure,which endows the samples high thermal storage density and high bending strength,but the decrease of bauxite/kaolin ratio leads to the decrease of mullite content,which reduces the properties of the samples.
文摘Exhaust emission regulations of the automotive are enforced in each country to prevent air pollution and global warming,and the restriction standard tends to become severer.Various techniques such as the combustion improvement of gasoline,upgrades of the catalyst,and the thermal capacity decreases in the exhaust lines are adopted to suit the regulations,and these lead to an increase of the maximum temperature of the exhaust gas. Recently,ferritic stainless steels are mainly used to parts of exhaust lines,as their thermal expansion coefficient is small,and the cyclic oxidation resistance and the thermal fatigue property are better than austenitic stainless steels. This paper presents newly developed heat-resistant stainless steels from Nisshin Steel for exhaust lines usage,and describes the currents of the steel development that could be envisaged in the future.With regard to improving the high-temperature strength of ferritic stainless steels,the addition of Nb,Mo and Cu is effective in solution hardening and precipitation hardening at 700℃,while the addition of Nb,Mo and W is effective in mainly solution hardening at 900℃.The addition of Cr,Si and Mn suppress the breakaway oxidation in air at 950℃up to 200 h of ferritic stainless steels containing 14%Cr.Especially,the addition of 0.8%or higher Mn would effectively improve the adherence of oxide scale.It is confirmed that ferritic stainless steels,NSSHR-1(14Cr-lMn-0.9Si-Nb) and NSSHR-2(10Cr-0.9Si-Nb-Ti ),is having a superior heat resistance,formability and cost performance compared to conventional Type441 and Type439 respectively.
文摘To solve the problem of the severe mismatch between the product and roll materials in the preliminary rolling line,a new graphitic steel material was designed,its microstructure and high-temperature friction and wear properties were investigated.Moreover,the feasibility of replacing semi-steel with this new material in the V1 stand roll was studied herein.The results show that the graphitic steel matrix is strengthened by silicon and nickel elements.The presence of spherical graphite also provides self-lubrication and heat conduction and prevents the propagation of cracks.Carbides in the appropriate amount and size strengthen the matrix,reduce the cracking effect of the matrix,and are not easily broken,thereby reducing high-temperature abrasive wear.Under the same hightemperature friction and wear conditions,compared with semi-steel,the wear-scar surface of graphitic steel exhibits less wear-scar depth and wear volume,a smaller friction coefficient,reduced oxide layer thickness,and fewer instances of peeling and microcracks.Therefore,the newly designed graphitic steel has higher wear resistance and hot-crack resistance than semi-steel,which makes it feasible for use in replacing semi-steel as a new V1 frame roll material in the blooming mill.
基金the National Key R & D Program of China (2018YFC1901501, 2018YFC1901503 and 2018YFC1901504)
文摘In order to realize the large-scale and high-value utilization of waste architectural ceramics,high-temperature resistant materials based on waste architectural ceramics were prepared with sodium silicate as the binder,clay/bauxite and metakaolin/bauxite as coating materials,and the cold strength obtaining mechanism was explored.The phase composition,the microstructure and the mechanical properties of the high temperature resistant materials based on waste architectural ceramics were tested and analyzed.The results showed that when the heat treatment temperature was between 110-1000℃,the strength of the samples mainly came from the physical adhesion of sodium silicate and fine powder.When the temperature rose to 1100℃,the strength of the sample was improved since the internal low-melting-point components melted and promoted sintering.The addition of clay and bauxite can effectively enhance the flexural strength of the samples when the heat treatment temperature is 1000℃.When the heat treatment temperature rises from 900 to 1000℃,the flexural strength of the samples will be enhanced owing to the formation of silica alumina spinel and mullite from metakaolin.
基金supported by the National Key Research and Development Program of China (2022YFC2104700)the National Natural Science Foundation of China (52273003,51988102)。
文摘Poly(diethyl fumarate-co-methoxyethyl acrylate-co-vinyl chloroacetate)(PDEFMV),a novel bio-based elastomer with a saturated structure,was synthesized via redox emulsion polymerization.The glass-transition temperatures of PDEFMV,adjusted through the variation of the diethyl fumarate-to-methoxyethyl acrylate feeding ratio,ranged from-36.1 to-14.8 ℃.The number-average molecular weights of PDEFMV ranged from 384,000 to 46,000 g/mol.In designing the molecular structure,vinyl chloroacetate was used to provide active sites for subsequent vulcanization and crosslinking.The active chlorine groups within the PDEFMV chain reacted with the crosslinking agent trithiocyanuric acid under high temperature and pressure to form a nonsulfur crosslinked three-dimensional network structure.To achieve the desired properties,carbon black(CB,N330) was incorporated to reinforce PDEFMV,leading to the formation of PDEFMV/CB composites.A comprehensive study was conducted on the high-temperature oil resistance of PDEFMV/CB composites.Following immersion in IRM903 oil at temperatures of 150 and 200 ℃ for 72 h,the mass and volume changes in PDEFMV/CB were lower than those observed in commercially available acrylate rubber(AR)/CB,indicating that PDEFMV exhibited superior oil resistance.Furthermore,the aging characteristics and mechanisms of oil resistance in the PDEFMV/CB and AR/CB composites were investigated at different temperatures(150,200,and 250 ℃).The results provide insights into the operational temperature ranges suitable for PDEFMV/CB and offer valuable guidance for potential industrial applications.
基金This work has been Sponsored by CNPC Innovation Found(Grant No.2021DQ02-0202)Besides,the authors gratefully appreciate the financial support of the Science Foundation of China University of Petroleum,Beijing(Grant No.2462020XKBH013)Financial supports from the National Natural Science Foundation of China(Grant No.52174046)is also significantly acknowledged.
文摘Conformance control and water plugging are a widely used EOR method in mature oilfields.However,majority of conformance control and water plugging agents are unavoidable dehydrated situation in high-temperature and high-salinity low permeability reservoirs.Consequently,a novel conformance control system HPF-Co gel,based on high-temperature stabilizer(CoCl_(2)·H_(2)O,CCH)is developed.The HPF-Co bulk gel has better performances with high temperature(120℃)and high salinity(1×10^(5)mg/L).According to Sydansk coding system,the gel strength of HPF-Co with CCH is increased to code G.The dehydration rate of HPF-Co gel is 32.0%after aging for 150 d at 120℃,showing excellent thermal stability.The rheological properties of HPF gel and HPF-Co gel are also studied.The results show that the storage modulus(G′)of HPF-Co gel is always greater than that of HPF gel.The effect of CCH on the microstructure of the gel is studied.The results show that the HPF-Co gel with CCH has a denser gel network,and the diameter of the three-dimensional network skeleton is 1.5-3.5μm.After 90 d of aging,HPF-Co gel still has a good three-dimensional structure.Infrared spectroscopy results show that CCH forms coordination bonds with N and O atoms in the gel amide group,which can suppress the vibration of cross-linked sites and improve the stability at high temperature.Fractured core plugging test determines the optimized polymer gel injection strategy and injection velocity with HPF-Co bulk gel system,plugging rate exceeding 98%.Moreover,the results of subsequent waterflooding recovery can be improved by 17%.
基金supported by the National Natural Science Foundation of China(51872212,51972244,52102066,and 62204179)the National Key R&D Program of China(2018YFE0103600,2021YFB3703100)+7 种基金the International Science&Technology Cooperation Program of Hubei Province,China(2022EHB024)the 111 Project(B13035)supported by the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030001)Key-Area Research and Development Program of Guangdong Province(2021B0707050001,2019B121204001,and 2020B010181001)the Chaozhou Science and Technology Project(2019PT01)the Self-innovation Research Funding Project of Hanjiang Laboratory(HJL202012A001,HJL202012A002,HJL202012A003)the Major Science and Technology Project in Zhongshan City,Guangdong Province(2019AG029)the Fundamental Research Funds for the Central Universities(WUT:2022IVA093).
文摘Multifunctional,wearable,and durable textiles integrated with smart electronics have attracted tremendous attention.However,it remains a great challenge to balance new functionalities with high-temperature stability.Herein,textile-based pressure sensors with excellent electromagnetic interference(EMI)shielding,Joule heating,and high-temperature resistance were fabricated by constructing graphene/SiC(G/SiC)heterostructures on carbon cloth via laser chemical vapor deposition(LCVD).The resultant textiles exhibited excellent EMI efficiency of 74.2 dB with a thickness of 0.45 mm,Joule heating performance within a low working voltage(V)range of 1-3 V,and fast response time within 20 s.These properties arose from multiple reflections,interfacial polarization,and high conductivity due to the numerous amounts of nanoscale G/SiC heterostructures.More importantly,G/SiC/carbon fibers(CFs)demonstrated well high-temperature resistance with a heat resistance index(THri)of 380.2 C owing to the protection of a coating layer on the CFs upon oxidation.Meanwhile,the G/SiC/CFs presented good pressure-sensing performance with high sensitivity(S)of 52.93 kPal,fast response time of 85 ms,and a wide pressure range of up to 186 kPa.These features imply the potential of the G/SiC/CFs as efficient EMI shielding,electrical heater,and piezoresistive sensor textiles.