期刊文献+
共找到2,140篇文章
< 1 2 107 >
每页显示 20 50 100
High Temperature Corrosion of Water Wall Materials T23 and T24 in Simulated Furnace Atmospheres 被引量:8
1
作者 赵钦新 张知翔 +2 位作者 成丁南 王云刚 邓翔 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第4期814-822,共9页
Candidate materials for water wall of supercritical and ultra-supercritical utility boilers,T23 and T24,were chosen as the experimental samples and exposed to oxidizing atmosphere,reducing atmosphere and oxidizing/red... Candidate materials for water wall of supercritical and ultra-supercritical utility boilers,T23 and T24,were chosen as the experimental samples and exposed to oxidizing atmosphere,reducing atmosphere and oxidizing/reducing alternating atmosphere separately.The corrosion temperature was 450-550?C.The effects of oxygen con-tent and temperature on the corrosion in reducing atmosphere and alternating atmosphere were investigated.The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) were used to examine the corroded samples.The results show that the corrosion kinetics of T23 and T24 can be described by the double logarithmic equation and parabolic equation respectively.To describe the corrosion of materials accurately it is not sufficient to analyze the macro-mass gain and the macro-thickness of the corroded layer only,but the EDS should be applied to examine the migration depth of corrosive elements O and S.It is revealed that the corrosion becomes more severe when H2S is present in the corrosive gas.S is more active than O,and Cr can reduce the migration of oxygen but not S.The combination corrosion of S and O and pure [S] has a stronger corrodibility than pure H2S.T24 suffers the most severe corrosion at oxygen content of 0.8%.Corrosion is aggravated when the corrosion temperature is above 450 ℃ in the alternating atmosphere.T23 has better corrosion resistance than T24 and W contributes a lot to the corrosion resistance of T23. 展开更多
关键词 stainless steel mass gain element migration high temperature corrosion
下载PDF
CO_(2) High Temperature Corrosion and Its Prevention of Chromia Forming Fe-base Alloys
2
作者 张建强 《表面技术》 EI CAS CSCD 北大核心 2021年第4期260-266,共7页
High temperature corrosion of chromia forming Fe-base alloys by CO_(2) produces not only oxidation but also carburisation.The corrosion kinetics in CO_(2)-rich gas is found to be increased compared with that in air or... High temperature corrosion of chromia forming Fe-base alloys by CO_(2) produces not only oxidation but also carburisation.The corrosion kinetics in CO_(2)-rich gas is found to be increased compared with that in air or oxygen.As a result,higher alloy chromium levels are required to achieve protective chromia formation in CO_(2).Corrosion reaction mechanisms in CO_(2) are examined and the internal carburisation of alloys in low carbon activity CO_(2) gases are analysed based on the variation of pO_(2) at the interface of oxide and metal.Carbon penetration through chromia oxide scale has been revealed by atom probe tomography.The strategies to resist CO_(2) corrosion are reviewed by alloying of Si and/or Mn,forming additional diffusion barrier layers,and by adding sulphur to modify oxide grain boundaries to reduce carbon diffusion along the grain boundaries. 展开更多
关键词 high temperature corrosion CO_(2) chromia-forming alloys carburisation ALLOYING
下载PDF
INFLUENCES OF SMALL AMOUNTS OF Y AND Ce ON HIGH TEMPERATURE CORROSION PROPERTIES OF M38 ALLOY
3
作者 Qi Hubin Wang Shujuan Li Tiefan 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 1992年第3期72-76,共5页
High temperature corrosion properties of M38 alloy with and without 0.04 wt-%Y and 0.05 wt-%Ce additions were studied in equilibrated S0_(2)+0_(2)gas mixtures at 850℃and 900℃.It was found that adding Y or Ce decreas... High temperature corrosion properties of M38 alloy with and without 0.04 wt-%Y and 0.05 wt-%Ce additions were studied in equilibrated S0_(2)+0_(2)gas mixtures at 850℃and 900℃.It was found that adding Y or Ce decreased the corrosion rate of M38 and changed considerably the surface morphologies and composition of corrosion products on M38.The effectiveness of Y and Ce were also discussed. 展开更多
关键词 Y Ce M38 alloy SO_(2)+O_(2)mixtures high temperature corrosion
下载PDF
Experimental study on the effect of H2S and SO2 on high temperature corrosion of 12Cr1MoV 被引量:9
4
作者 Hong Xu Shangkun Zhou +3 位作者 Yiming Zhu Weigang Xu Xiaohe Xiong Houzhang Tan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第8期1956-1964,共9页
Aiming at the high temperature corrosion in a coal-fired boiler,the effect of H2S and SO2 on the corrosion of 12 CrlMoV under the water wall condition has been investigated by experiments.The results indicate that H2 ... Aiming at the high temperature corrosion in a coal-fired boiler,the effect of H2S and SO2 on the corrosion of 12 CrlMoV under the water wall condition has been investigated by experiments.The results indicate that H2 S can promote the corrosion significantly,and the coarse porous oxide film formed cannot stop the progress of corrosion.While SO2 presents little effect on the corrosion.The main composition of the surface of 12 CrlMoV corrosion products is Fe2 O3.With H2S in the atmosphere,the corrosion gradually develops into deeper layers by forming FeS,FeO and Fe2 O3 alternately.The corrosion rate is doubled for every 50℃ inerease in temperature at 400-500℃. 展开更多
关键词 high temperature corrosion Water WALL 12CR1MOV H2S SO2
下载PDF
Investigation and Analysis of High Temperature Corrosion and Degradation of Marine Boiler Combustion Swirler
5
作者 RS Virdi DG Thakur 《Journal of Marine Science and Application》 CSCD 2016年第1期86-94,共9页
The present paper investigated and analyzed swirler material consisting of mild steel which was subjected to service for the period of one year in a 30 MW marine boiler. Due to the presence of high temperatures in the... The present paper investigated and analyzed swirler material consisting of mild steel which was subjected to service for the period of one year in a 30 MW marine boiler. Due to the presence of high temperatures in the furnace coupled with the corrosive marine environment swirler material showed accelerated degradation and material wastage. An investigation into the feasibility of manufacturing the existing swirler with an alternate material or coating the swirler material with a thermal barrier coating was undertaken. Based on their properties and performance, SS 304 and SS 316 were proposed as the replacement materials for the swirler. The other alternative of coating the existing swirlers with a form thermal barrier coating to observe for any improvement in their performance at elevated temperatures was also tested. Stellite, which is a Ni-Co based coating, was carried out on the MS samples and the same were exposed to same temperatures mentioned above. The performance of the available options was evaluated with respect to the grain structure of the material, the hardness value of the materials and deterioration at elevated temperatures. Investigation showed the proposed materials/ coatings like SS 304, SS 316 and Stellite coating revealed that SS 316 is the material best suited for high temperature application. 展开更多
关键词 marine boiler corrosion DEGRADATION high temperature SWIRLER stainless steel
下载PDF
High temperature corrosion behavior of arc-sprayed aluminum coatings on steel
6
作者 SUN Jian-bo WANG Yong DONG Li-xian 《中国有色金属学会会刊:英文版》 CSCD 2004年第z1期451-454,共4页
Aluminum coatings were sprayed on the substrate of steel Q235 by arc spraying. The test samples of Q235, Al coatings and Al coatings with seal coat were placed in box type electric resistance furnace at 400, 500,600, ... Aluminum coatings were sprayed on the substrate of steel Q235 by arc spraying. The test samples of Q235, Al coatings and Al coatings with seal coat were placed in box type electric resistance furnace at 400, 500,600, 650 ℃ when their oxidation behaviors were studied. And their oxidation kinetics curves were protracted. Microstructure, microhardness, bond strength and distribution of section elements were investigated by optical microscope(OM), Vickers microhardness instrument, electric tensile test machine and EPMA. Al coatings and Al coatings with seal coat can enhance the oxidation-resistance of substrate under 500 ℃. The latter has the best corrosion resistance. The coatings can't protect the substrate against oxidation above 600 ℃. After a long time corrosion there is enriched oxygen element at interface. 展开更多
关键词 arc SPRAYING AL COATING AL COATING with seal COAT high temperature corrosion oxidation kineticscurve
下载PDF
SULFATE RESISTANCE MECHANISM OF HIGH- PERFORMANCE CONCRETE CONTAINING NCI 被引量:2
7
作者 MA Baoguo Wuhan University of Technology 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1999年第1期6-15,共10页
It is found that the incorporation of Nitrite Corrosion Inhibitor (NCI) greatly weakens the resistance of mixtures to sulfate attack. To study the mechanism of this phenomenon, in this paper, the influence of NCI add... It is found that the incorporation of Nitrite Corrosion Inhibitor (NCI) greatly weakens the resistance of mixtures to sulfate attack. To study the mechanism of this phenomenon, in this paper, the influence of NCI addition on the cement paste and microstructure change of high performance concrete specimens is studied by means of quantitative XRD, SEM tests. The results demonstrate that the incorporation of NCI accelerates the formation of calcium hydroxide and ettringite crystals, and weakens the pore refinement effect caused by the secondary hydration reaction of fly ash and microsilica. At the age up to one year, the relative crystal quantity in mixture containing NCI is always higher than that in control mixture. The reasons for the degradation in sulfate resistance of mixtures may be attributed to the increase and stability of the calcium hydroxide and ettringite crystals formed and the weakening of secondary hydration reaction. Based on the results, conclusion can be drawn that NCI should be used cautiously in practical engineering where high resistance to sulfate attack is required. (Author abstract) 7 Refs. 展开更多
关键词 nitrite corrosion inhibitor high-performance concrete MICROSTRUCTURE sulfate resistance
下载PDF
Improving corrosion resistance of additively manufactured WE43 magnesium alloy by high temperature oxidation for biodegradable applications
8
作者 Jinge Liu Bangzhao Yin +7 位作者 Fei Song Bingchuan Liu Bo Peng Peng Wen Yun Tian Yufeng Zheng Xiaolin Ma Caimei Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期940-953,共14页
Laser powder bed fusion(L-PBF)has been employed to additively manufacture WE43 magnesium(Mg)alloy biodegradable implants,but WE43 L-PBF samples exhibit excessively rapid corrosion.In this work,dense WE43 L-PBF samples... Laser powder bed fusion(L-PBF)has been employed to additively manufacture WE43 magnesium(Mg)alloy biodegradable implants,but WE43 L-PBF samples exhibit excessively rapid corrosion.In this work,dense WE43 L-PBF samples were built with the relativity density reaching 99.9%.High temperature oxidation was performed on the L-PBF samples in circulating air via various heating temperatures and holding durations.The oxidation and diffusion at the elevated temperature generated a gradient structure composed of an oxide layer at the surface,a transition layer in the middle and the matrix.The oxide layer consisted of rare earth(RE)oxides,and became dense and thick with increasing the holding duration.The matrix was composed ofα-Mg,RE oxides and Mg_(24)RE_(5) precipitates.The precipitates almost disappeared in the transition layer.Enhanced passivation effect was observed in the samples treated by a suitable high temperature oxidation.The original L-PBF samples lost 40%weight after 3-day immersion in Hank’s solution,and broke into fragments after 7-day immersion.The casted and solution treated samples lost roughly half of the weight after 28-day immersion.The high temperature oxidation samples,which were heated at 525℃ for 8 h,kept the structural integrity,and lost only 6.88%weight after 28-day immersion.The substantially improved corrosion resistance was contributed to the gradient structure at the surface.On one hand,the outmost dense layer of RE oxides isolated the corrosive medium;on the other hand,the transition layer considerably inhibited the corrosion owing to the lack of precipitates.Overall,high temperature oxidation provides an efficient,economic and safe approach to inhibit the corrosion of WE43 L-PBF samples,and has promising prospects for future clinical applications. 展开更多
关键词 Laser powder bed fusion Biodegradable magnesium alloy high temperature oxidation corrosion resistance WE43.
下载PDF
Deterioration Mechanisms of Sulfate Attack on Concrete under Alternate Action 被引量:8
9
作者 高润东 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第2期355-359,共5页
By micro- and macro-observations, the deterioration mechanisms of concrete under alternate action between repeated sub-high temperature/cooling by water and sodium sulfate solution attack (TW-SA) were studied; meanw... By micro- and macro-observations, the deterioration mechanisms of concrete under alternate action between repeated sub-high temperature/cooling by water and sodium sulfate solution attack (TW-SA) were studied; meanwhile, the single sodium sulfate solution attack (SA) was also done as comparison. Micro-observations included the analysis of attack products by thermal analysis method and the determination of sulfate-ion content from surface to interior by chemical titrating method (modified barium sulfate gravimetric method). Macro-observations mainly included the mechanical behaviors such as compressive strength, splitting strength. The experimental results indicate, in both cases, the main attack product is ettringite, only in the first layer of case SA some gypsum is checked; in case SA, the sulfate ions mainly concentrate in the surface layer, so the attack is relatively mild; but in case TW-SA, the repeated sub-high temperature/cooling by water promotes the sulfate ions diffusing inwards, which leads to obvious strength degradation. 展开更多
关键词 CONCRETE sulfate repeated sub-high temperature/cooling by water attack product sulfate-ion content strength
下载PDF
Promotion effect of bulk sulfates over CeO_(2)for selective catalytic reduction of NO by NH_(3)at high temperatures 被引量:1
10
作者 Jiawei Ji Li Han +4 位作者 Wang Song Jingfang Sun Weixin Zou Changjin Tang Lin Dong 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第5期311-314,共4页
Understanding the influence of sulfates over catalysts for selective catalytic reduction of NO with NH_(3)(NH_(3)-SCR)is crucial due to the universal presence of SO_(2)in exhaust gas.Depending on the degree of sulfati... Understanding the influence of sulfates over catalysts for selective catalytic reduction of NO with NH_(3)(NH_(3)-SCR)is crucial due to the universal presence of SO_(2)in exhaust gas.Depending on the degree of sulfation,there mainly exist surface and bulk sulfates and NH_(3)-SCR activity is generally considered to suffer more from bulk sulfates.Herein,the unique function of bulk sulfates over Ce O_(2)in promoting hightemperature SCR reaction is revealed.Notably,compared with CeO_(2)dominated with surface sulfates(S-CeO_(2)-4h)and commercial V_2O_5-WO_(3)/TiO_(2),CeO_(2)with bulk sulfates(S-Ce O_(2)-72h)exhibits admirable NO conversion at the temperature range of 400-550℃.Bulk sulfates provide more Br?nsted acid sites with stronger strength for NH_(3)adsorption.Moreover,the oxidation ability of Ce O_(2)is significantly inhibited due to electron-withdrawing effect from bulk sulfates,which alleviates NH_(3)oxidation at high temperatures.More NH_(3)adsorption with high stability and limited NH_(3)oxidation capacity ensure the excellent catalytic performance for S-CeO_(2)-72h in high-temperature denitration.This work provides new insight of bulk sulfates in promoting SCR activity and open a new avenue to design de NO_xcatalysts employed at high temperatures. 展开更多
关键词 NH_(3)-SCR CeO_(2) Bulk sulfates high temperature denitration NH_(3)adsorption NH_(3)oxidation
原文传递
Mechanical properties and damage constitutive model of sandstone after acid corrosion and high temperature treatments 被引量:2
11
作者 Qijian Chen Youliang Chen +3 位作者 Peng Xiao Xi Du Yungui Pan Rafig Azzam 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第6期747-760,共14页
Aiming at the problem of temperature-mechanics-chemical(T-M-C)action encountered by rocks in underground engineering,sandstone was selected as the sample for acid corrosion treatment at pH 1,3,5 and 7,the acid corrosi... Aiming at the problem of temperature-mechanics-chemical(T-M-C)action encountered by rocks in underground engineering,sandstone was selected as the sample for acid corrosion treatment at pH 1,3,5 and 7,the acid corrosion treated samples were then subjected to high-temperature experiments at 25,300,600,and 900℃,and triaxial compression experiments were conducted in the laboratory.The experimental results show that the superposition of chemical damage and thermal damage has a significant impact on the quality,wave velocity,porosity and compression failure characteristics of the rock.Based on the Lemaitre strain equivalent hypothesis theory,the damage degree of rock material was described by introducing damage variables,and the spatial mobilized plane(SMP)criterion was adopted.The damage constitutive model can well reflect the stress-strain characteristics of the rock triaxial compression process,which verified the rationality and reliability of the model parameters.The experiment and constitutive model analyzed the change law of mechanical properties of rock after chemical corrosion and high temperature thermal damage,which had certain practical significance for rock engineering construction. 展开更多
关键词 Acid corrosion high temperature Mechanical properties Damage variable SMP criterion Constitutive model
下载PDF
Protective Effect of the Sputtered TiAlCrAg Coating on the High-Temperature Oxidation and Hot Corrosion Resistance of Ti-Al-Nb Alloy 被引量:4
12
作者 YanjunXI FuhuiWANG LianlongHE 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第6期724-727,共4页
The effect of a sputtered Ti-48AI-8Cr-2Ag (at. pct) coating on the oxidation resistance of the cast Ti-46.5AI-5Nb (at. pct) alloy was investigated in air at 1000-1100℃. Hot corrosion in molten 75 wt pct Na2SO4+25 wt ... The effect of a sputtered Ti-48AI-8Cr-2Ag (at. pct) coating on the oxidation resistance of the cast Ti-46.5AI-5Nb (at. pct) alloy was investigated in air at 1000-1100℃. Hot corrosion in molten 75 wt pct Na2SO4+25 wt pct K2SO4 was investigated at 900℃. The scale on the cast TiAINb tends to spall in air, while the scale on coating is very adherent. The sputtered Ti-48AI-8Cr-2Ag coating remarkably improved high temperature oxidation resistance of the cast Ti-46.5AI-5Nb alloy because of the formation of an adherent Al2O3 scale. Due to the inward diffusion of Cr, Kirkendall voids were found at the coating/substrate interface. TiAICrAg coating provided excellent hot corrosion resistance for TiAINb alloy in molten 75 wt pct Na2SO4+25 wt pct K2S04 at 900℃ due to the formation of a continuous Al_2O_3 scale. 展开更多
关键词 high temperature oxidation TiAlCrAg coating Hot-corrosion
下载PDF
Study of corrosion behavior of labeling medium on Fe-36%Ni cold-rolled strip used in LNG carriers in high-temperature and high-humidity environment
13
作者 WANG Xueting LV Jiansheng TIAN Yuxin 《Baosteel Technical Research》 CAS 2020年第1期39-43,共5页
To fulfill the high-quality surface requirements of the Fe-36% Ni cold-rolled strip used in liquid natural gas carriers,corrosion tests were conducted on alloy surfaces using ink media with different composition in hi... To fulfill the high-quality surface requirements of the Fe-36% Ni cold-rolled strip used in liquid natural gas carriers,corrosion tests were conducted on alloy surfaces using ink media with different composition in hightemperature and high-humidity conditions.The results show that the Cl^-content in ink is the main cause of surface corrosion of Fe-36%Ni alloy at 95%RH and 50℃ Cl^- penetrates the passivation film,causing pitting on the surface.This corrosive material primarily comprises elements Fe and O.After 120 h of high temperature and high humidity,pitting had occurred on the surface,which was characterized by irregularly distributed areas of bright red filamentous corrosion.With time,the corrosion gradually deepened and expanded to nearby areas.However,when the ink medium contained no Cl^-,no corrosion was found on the alloy surface.As such,during the production of Fe-36%Ni material and its application in LNG shipbuilding,care must be taken in the selection of the marker or medium that will come into contact with the strip surface to ensure that it contains no corrosive ions like Cl^-. 展开更多
关键词 corrosion Cl^- Fe-36%Ni high temperature and high humidity LNG
下载PDF
High-temperature corrosion-resistance performance of electro-thermal explosion spraying coating
14
作者 魏世丞 徐滨士 +1 位作者 王海斗 金国 《Journal of Central South University》 SCIE EI CAS 2005年第S2期195-198,共4页
As a new spraying technology used in the remanufacturing engineering, electro-thermal explosion spraying holds a lot of advantages. Electro-thermal explosion spraying coating aliquation phenomena are reduced and non-c... As a new spraying technology used in the remanufacturing engineering, electro-thermal explosion spraying holds a lot of advantages. Electro-thermal explosion spraying coating aliquation phenomena are reduced and non-crystal, micro-crystal and millimicron-crystal and other microstructure are formed. The corrosion-resistance ability of electro-thermal explosion spraying coating in high temperature environment was surveyed respectively. SEM equipped with EDS was employed to analyze the microstructure of spraying coating before and after corrosion. The corrosion-resistance mechanism of the spraying coating was discussed. 展开更多
关键词 high temperature corrosion-RESISTANCE electro-thermal explosion SPRAYING COATING
下载PDF
Accelerated Corrosion of Pure Fe Induced by Gaseous ZnCl_2 at High Tempreratures 被引量:2
15
作者 HaitaoMA LaiWANG YuanshiLI 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第5期456-458,共3页
ZnCl2 is one of the dominant aggressive species in waste incinerators or other advanced combustion power generation systems. In this study, the influence of minor amount of gaseous ZnCl2 on the corrosion behavior of p... ZnCl2 is one of the dominant aggressive species in waste incinerators or other advanced combustion power generation systems. In this study, the influence of minor amount of gaseous ZnCl2 on the corrosion behavior of pure iron was examined at 600-800℃ in a pure oxygen environment. The corrosion rate usually increased markedly with increasing temperatures at a fixed ZnCl2 content or with increased ZnCl2 contents at a constant temperature. The corrosion products were composed of a thin outer layer of ZnFe2O4 spinel and an inner zone with a much thicker layer of Fe2O3, which exhibited a serious separation from the matrix. Moreover, a molten FeCl2 layer was observed at the scale substrate interface. The accelerated corrosion of pure iron was attributed to the existence of FeCl2 with low melting point on the metal surface, which destroyed the cohesion and adhesion of the oxide scale. The results are discussed in relation to the thermodynamic factors and the presence of volatile compounds in the reaction system. 展开更多
关键词 high temperature corrosion OXIDATION Cillorination FE Gaseous
下载PDF
Pitting corrosion and crevice corrosion behaviors of high nitrogen austenitic stainless steels 被引量:16
16
作者 Hua-bing Li Zhou-hua Jiang Yan Yang Yang Cao Zu-rui Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2009年第5期517-524,共8页
Pitting corrosion and crevice corrosion behaviors of high nitrogen austenitic stainless steels (HNSS) were investigated by electrochemical and immersion testing methods in chloride solution, respectively. The chemic... Pitting corrosion and crevice corrosion behaviors of high nitrogen austenitic stainless steels (HNSS) were investigated by electrochemical and immersion testing methods in chloride solution, respectively. The chemical constitution and composition in the depth of passive films formed on HNSS were analyzed by X-ray photoelectron spectrum (XPS). HNSS has excellent pitting and crevice corrosion resistance compared to 316L stainless steel. With increasing the nitrogen content in steels, pitting potentials and critical pitting temperature (CPT) increase, and the maximum, average pit depths and average weight loss decrease. The CPT of HNSS is correlated with the alloying element content through the measure of alloying for resistance to corrosion (MARC). The MARC can be expressed as an equation of CPT=2.55MARC-29. XPS results show that HNSS exhibiting excellent corrosion resistance is attributed to the enrichment of nitrogen on the surface of passive films, which forms ammonium ions increasing the local pH value and facilitating repassivation, and the synergistic effects of molybdenum and nitrogen. 展开更多
关键词 high nitrogen austenitic stainless steel pitting corrosion crevice corrosion NITROGEN critical pitting temperature syner-gistic effect
下载PDF
Preparation and properties of Ni-coated WC powder and highly impact resistant and corrosion resistant WC-Ni cemented carbides 被引量:5
17
作者 Fan-lu MIN Song-bai YU +4 位作者 Sheng WANG Zhan-hu YAO Jacques Guillaume NOUDEM Si-jin LIU Jian-feng ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第6期1935-1947,共13页
WC powders were uniformly coated by Ni nanoparticles through a combined chemical co-precipitation and subsequent high temperature hydrogen reduction strategy(abbreviated as CM-WCN),and then were consolidated by vacuum... WC powders were uniformly coated by Ni nanoparticles through a combined chemical co-precipitation and subsequent high temperature hydrogen reduction strategy(abbreviated as CM-WCN),and then were consolidated by vacuum sintering at 1450°C for 1 h to obtain WC−Ni cemented carbides.The microstructure and properties of the as-consolidated CM-WCN were investigated.The average grain size of WC in the consolidated CM-WCN was calculated to be in the range of 3.0−3.8μm and only few pores were observed.A relative density of 99.6%,hardness of HRA 86.5 and bending strength of 1860 MPa were obtained for the CM-WCN−10wt.%Ni,and the highest impact toughness of 6.17 J/cm^(2 )was obtained for the CM-WCN−12wt.%Ni,surpassing those of the hand mixed WC−Ni(HM-WCN)cemented carbides examined in this study and the other similar materials in the literature.CM-WCN cemented carbides possess excellent mechanical properties,due to their highly uniform structure and low porosity that could be ascribed to the intergranular-dominated fracture mode accompanied by a large number of plastic deformation tears of the bonding phase.In addition,the corrosion resistance of CM-WCN was superior to that of HM-WCN at the Ni content of 6−12 wt.%. 展开更多
关键词 WC−Ni cemented carbides chemical co-precipitation method high temperature hydrogen reduction strategy Ni content microstructure impact toughness corrosion resistance
下载PDF
适应锅炉调峰运行的水冷壁高温腐蚀预测模型 被引量:2
18
作者 邓磊 袁茂博 +3 位作者 杨家辉 岳洋 姜家豪 车得福 《化工进展》 EI CAS CSCD 北大核心 2024年第2期925-936,共12页
随着可再生能源大规模并网,传统火电机组作为调配能源的地位显著增强,这对锅炉灵活调峰运行的安全稳定性提出了更高要求。本文耦合烟气侧与工质侧传热,结合管壁温计算,形成水冷壁壁温分布耦合计算方法。同时,建立了用于确定还原性气氛... 随着可再生能源大规模并网,传统火电机组作为调配能源的地位显著增强,这对锅炉灵活调峰运行的安全稳定性提出了更高要求。本文耦合烟气侧与工质侧传热,结合管壁温计算,形成水冷壁壁温分布耦合计算方法。同时,建立了用于确定还原性气氛下的燃料硫释放以及含硫组分的相互转化过程的SO_(x)生成模型。综合炉膛数值模拟、水冷壁壁温耦合计算以及包含时间维度的管壁高温腐蚀模型,提出了一种适应锅炉调峰运行的水冷壁高温腐蚀预测模型并基于Matlab GUI开发了对应软件。选取一台超临界600MW四角切圆燃煤锅炉为研究对象,结果表明:采用壁温耦合计算模型和SO_(x)生成模型得到水冷壁的壁温分布和近壁面H_(2)S浓度分布准确度高,为水冷壁高温腐蚀的准确预测提供了良好基础。不同负荷下水冷壁高温腐蚀特征存在差异,壁面腐蚀程度整体上随负荷降低而降低。100%BMCR与75%THA负荷下前墙水冷壁燃烧器与SOFA之间的区域腐蚀最为严重,最大年腐蚀深度分别为276μm和233μm;50%THA与35%BMCR负荷下高温腐蚀深度在燃烧器区域的上部迅速增加至最大值,分别为224μm和256μm。多工况运行水冷壁高温腐蚀状态表现为各工况腐蚀状态的时空叠加。运用水冷壁高温腐蚀预测模型可实现通过锅炉运行参数和运行时间预测多工况下水冷壁高温腐蚀状态程度的时空分布。 展开更多
关键词 调峰运行 水冷壁 高温腐蚀 数值模拟 壁温计算
下载PDF
高含硫天然气净化装置腐蚀特征与典型腐蚀案例分析 被引量:2
19
作者 裴爱霞 《炼油技术与工程》 CAS 2024年第2期50-55,共6页
相关高含硫天然气净化装置的工程建设、设备制造、材料选型等标准规范较少,多采用或借鉴石油炼制行业标准。普光气田天然气净化厂自2009年投产至今,因高酸性气体腐蚀,以及酸性气体、制造缺欠、材料缺陷等多因素耦合腐蚀,引发装置设备或... 相关高含硫天然气净化装置的工程建设、设备制造、材料选型等标准规范较少,多采用或借鉴石油炼制行业标准。普光气田天然气净化厂自2009年投产至今,因高酸性气体腐蚀,以及酸性气体、制造缺欠、材料缺陷等多因素耦合腐蚀,引发装置设备或设施多次泄漏,成为制约工厂安全、高效、长周期运行的主要问题。通过统计分析历年异常事件、设备检维修台账、压力容器管道检测台账等,归纳了高含硫净化装置重点腐蚀区域、影响因素、腐蚀机理,得出湿硫化氢腐蚀、高温硫腐蚀、二氧化硫腐蚀、垢下腐蚀为主要腐蚀形式;从区域、类别、诱因等不同角度归纳了腐蚀分布规律,脱硫、硫磺回收系统腐蚀占比达80%以上;重点剖析了基于硫化氢、液硫、制造缺欠等因素的典型腐蚀案例,提出了高含硫天然气净化装置腐蚀防控措施,为同类酸性气田装置、设备腐蚀监检测和防控提供了借鉴。 展开更多
关键词 高含硫天然气 净化装置 腐蚀特征 腐蚀规律 泄漏 酸性气 高温硫 制造缺欠
下载PDF
燃煤锅炉温度场与高温腐蚀气氛场同步在线检测装置开发及应用 被引量:1
20
作者 王建荣 程银雪 +6 位作者 李龙 郭古青 田亚莉 孙小聪 周月婷 李传亮 邱选兵 《电力科技与环保》 2024年第2期116-124,共9页
燃煤锅炉主燃区燃烧场的经济性、安全性和环保性对于智慧电厂建设具有重要意义。其中,水冷壁近壁面高温腐蚀H_(2)S和CO气体浓度的实时在线监测尤为重要。为实现燃煤锅炉主燃区温度场和高温腐蚀气氛场的同步测量,基于红外热成像原理,采用... 燃煤锅炉主燃区燃烧场的经济性、安全性和环保性对于智慧电厂建设具有重要意义。其中,水冷壁近壁面高温腐蚀H_(2)S和CO气体浓度的实时在线监测尤为重要。为实现燃煤锅炉主燃区温度场和高温腐蚀气氛场的同步测量,基于红外热成像原理,采用Optris-PI1M小型红外热成像仪,基于LabVIEW温度实时采集应用软件,在炉膛的观察口对主燃区温度场进行连续监测。以低成本1.5μm附近的通信波段激光器作为测量高温腐蚀气体H_(2)S和CO的激光光源,并结合波长调制光谱技术和频分复用技术,以实现H_(2)S和CO气体浓度的同步检测。线性度实验表明,其线性拟合相关系数为0.9995。将研制的同步检测仪器对某300 MW四角切圆燃煤锅炉的主燃区的温度场和气氛场进行了现场应用试验。现场测试结果表明,锅炉主燃区温度主要分布范围在1300~1400℃,最高温度达到了1500℃;同时得到了锅炉主燃区的H_(2)S和CO浓度分布,H_(2)S浓度在12~125 mg/m^(3)的范围内波动,而CO浓度主要分布在10%~20%之间,最高可达22%;炉内H_(2)S和CO的浓度呈正相关,氧气浓度保持在1%以下,由于厌氧燃烧会导致两种气体的含量增加,从而造成对水冷壁近壁面的高温腐蚀。 展开更多
关键词 燃煤锅炉 高温腐蚀 红外热成像 激光吸收光谱 在线监测
下载PDF
上一页 1 2 107 下一页 到第
使用帮助 返回顶部