LI Hui-bin
,
WANG Hua
,
QI Yi-long
,
HU Jian-hang
,
LI You-ling
钢铁研究学报(英文版)
Total ilmenite from Yunnan, China, difficult to smelt in blast furnace, was smelted by oxygen-enriched top-blown smelting reduction ironmaking technology. Much more details on smelting were discussed. Specifically, the influence of reduction temperature, slag basicity and molar ratio of carbon to oxygen on the reduction quality level including iron recovery and titanium and sulfur contents in the pig iron produced in the experiment was investigated. Iron recovery rate could reach 95% with titanium content below 005% in pig iron produced, under the conditions of holding time of 30 min at 1823 K, basicity of 11, carbon to oxygen molar ratio of 10 and oxygen-enriched flow rate of 250 L/h. Oxidization potential of top-space of smelting reduction vessel and slag combination could create the driving force to partition phosphorous, titanium and silicon into the slag, which ensured low contents of the impurities involved above and carbon in pig iron. In addition, it avoided the generation of Ti(C,N) that could reduce interfacial tension of slag, which induced the formation of foaming slag seriously. Furthermore, jam of chargings and bubble flooding would be triggered, resulting in deterioration of BF state, increase of iron loss and decline of desulfurization rate.
关键词:
smelting reduction
,
ilmenite
,
iron recovery
,
desulfurization
王君
,
邹家桂
,
陈政标
,
高建武
,
刘彦坤
,
张杰元
,
宋莎
绝缘材料
为解决苯乙烯和甲基苯乙烯在VPI浸渍树脂应用于风力发电机中的不足，采用不饱和聚酯亚胺、引发剂和无挥发活性稀释剂研制出116HU聚酯亚胺无挥发浸渍树脂，并对其各项性能进行了研究。结果表明：116HU聚酯亚胺无挥发浸渍树脂的常规性能满足风力发电机的要求，其耐热等级可达H级。用该树脂浸渍的风电模拟线棒具有优异的介电性能、耐湿热交变和高低温循环冲击性能及耐盐雾性能等，能满足风力发电机在极端环境运行的要求。
关键词:
聚酯亚胺
,
无挥发
,
VPI
,
风力发电机
,
耐湿热
,
耐盐雾
王丽
,
魏巍
,
吴林钢
,
王灿进
液晶与显示
doi:10.3788/YJYXS20142903.0429
提出一种SAR图像目标识别新方法.首次引入BM3D方法,用于滤除原始图像中的相干斑噪声,BM3D结合了空间域和变换域去噪的优势,滤波性能优异.在特征提取步骤,将低阶Hu矩与高阶Zernike矩组合,Hu矩描述目标的粗略信息,高阶Zernike矩描述目标的细节信息,因此组合矩能够更加全面而细致地表达目标特性.使用组合矩特征训练SVM分类器,对含噪的SAR图像进行识别实验.实验结果表明:本文方法的识别率高达98.90％,优于已有的SAR目标识别方法.
关键词:
SAR图像
,
目标识别
,
BM3D滤波
,
组合矩
徐菊良
,
邓博
,
孙涛
,
李劲
,
蒋益明
金属学报
doi:10.3724/SP.J.1037.2009.00598
利用Thermo-Calc软件并结合金相显微镜,定性研究了2205双相不锈钢在800℃下敏化不同时间后的微观组织演变过程.通过研究扫描速率、介质成分、介质温度和试样表面状态优化了双环电化学动电位再活化法(DL-EPR),并用该优化方法研究了2205双相不锈钢晶间腐蚀敏感性.结果表明:DL-EPR法能定量评价σ相对2205双相不锈钢晶间腐蚀敏感性的影响,随敏化时间延长,σ相含量增多,晶jian 腐蚀敏感性也随之增加.腐蚀形貌的观测验证了这一规律,
关键词:
2205双相不锈钢
,
DL-EPR
,
晶间腐蚀敏感性
,
σ相
刘建国
,
安振涛
,
张倩
,
杜仕国
,
姚凯
,
王金
材料导报
doi:10.11896/j.issn.1005-023X.2017.04.030
为评估氧化剂硝酸羟胺的热稳定性,使用标准液体铝皿于3 K/min、4 K/min、5 K/min加热速率下进行热分析.借助非等温DSC曲线的参数值,应用Kissinger法和Ozawa法求得热分解反应的表观活化能和指前因子,根据Zhang-Hu-Xie-Li公式、Hu-Yang-Liang-Xie公式、Hu-Zhao-Gao公式以及Zhao-Hu-Gao公式,计算硝酸羟胺的自加速分解温度和热爆炸临界温度,并对热分解机理函数进行了研究.设计了7条热分解反应路径,采用密度泛函理论B3LYP/6-311++G(d,p)方法对硝酸羟胺的热分解进行了动力学和热力学计算.计算结果表明,硝酸羟胺热分解的自加速分解温度TsADT=370.05 K,热爆炸临界温度Te0=388.68K,Tbp0=397.54 K,热分解最可几机理函数的微分形式为f(a) =17×(1-α)18/17.硝酸羟胺热分解各路径中,动力学优先支持路径Path 6、Path 5、Path 4和Path 1生成NO和NO2,其次是Path 2、Path 7和Path 3生成N2和N2O.温度在373 K以下时,Path 1'反应无法自发进行,硝酸羟胺无法进行自发的热分解.从热力学的角度来看,硝酸羟胺在370.05K以下储存是安全的.
关键词:
硝酸羟胺
,
热分析
,
热稳定性
,
热分解机理
,
密度泛函理论
金属学报(英文版)
桑危郑牛樱裕桑牵粒裕桑希巍。希啤。龋伲模遥希牵牛巍。桑危模眨茫牛摹。模眨茫裕桑蹋拧。拢遥桑裕裕蹋拧。裕遥粒危樱桑裕桑希巍。桑巍。罚保罚怠。粒蹋眨停桑危眨汀。粒蹋蹋希?##2##3##4##5INVESTIGATIONOFHYDROGENINDUCEDDUCTILEBRITTLETRANSITIONIN7175ALUMINUMALLOY$R.G.Seng:B.JZhong,MG.ZengandP.Geng(DepartmentofMaterialsScierce,ScienceCollege,NorthearsternUniveisity,Shenyang110006,ChinaMaruscriptreceived4September1995inrevisedform20April1996)Abstrac:Effectsofhydrogenonthemechanicalpropertiesofdifferentlyaged7175aluminumalloyswereinvestigatedbyusingcathodicH-permeation,slowstrainratetensionandsoon.Theresultsindicatethatboththeyieldstressandthepercentagereductionofareadecreasewithincreasinghydrogenchargingtime,andthedegreeofreductiondecreasesasagingtimeincreasesforthesamehydrogenchargingtime.Keywords:hydrogeninducedductile-brittletransition,7175aluminumalloy,mechanicalproperty,cathodicH-permeation1.IntroductionForalongtimehydrogenembrittlementproblemwasthoughttobeabsentinhighstrengthaluminiumalloybecausethesolutiondegreeofhydrogeninaluminumatcommontemperatureandpressureisverysmall.However,hydrogenembrittlementphenomenonwasfoundinaluminumalloyduringtheinvestigationofstresscorrosionandcorrosionfatigue[1-5].Therehavebeenonlyafewreportsofhydrogeninducedsofteningandhardening.Inthispaper,theeffectsofhydrogenonmechanicalpropertiesof7175aluminumalloywereinvestigatedbyusingcathodicalchargingwithhydrogenandslowtensiontests.2.ExperimentalProcedureTheexperimentalmaterialwas7175aluminumalloyforgingintheformofa43mminthicknessandwithcomposition(wt%).5.41Zn,2.54Mg.1.49Cu,0.22Cr,0.1Mn.0.1Ti,0.16Fe.0.11Si,balancedbyA1.Alloyplateof1.5mminthicknesswasobtainedbyhot(465℃)andtoldrollingto83%reductioninthickness.Thelongaxisofhydrogenchargedspecimensisalongtherollingdirection.Allspecimensweresolidsolutionedat480℃for70min,followedtyimmediatequenchinginwaterandthenagedat140℃for6h(A),16h(B)and98h(C).Thetreatmentof6hiscorrespondingtotheunderagedstate.16hthefirstpeak-agedstateand98hthesecondpeak-agedstate.Thespecimenswerepolishedsuccessivelyusingemerypaperbeforehydrogencharging.Thetensilespecimenswerecathodicallychargedina2NH_2SO_4solutionwithasmallamountofAs_2O_3forpromotinghydrogenabsorption,andwithacurrentdensityof20±1mA/cm￣2atroomtemperature.ThehydrogencontentanalysiswascarriedoutonanLT-1Amodelionmassmicroprobeafterthesputteringdepthreached8nm.Theioncurrentsofhydrogenandaluminuminvariousagedstateswererecordedunderthesamecondition.ThetensiletestswereperformedonanAG-10TAmodeltestmachinewhichwascontrolledbycomputer.3.ExperimentalResultsTheratioofioncurrentstrengthofhydrogentoaluminumisrelatedtohydrogenconcentrationinhydrogenchargedspecimen.TheresultswereshowninTable1Thehydrogencontentincreaseswiththeincreaseincharingtime.Ofthethreeagedstates,theunderagedspecimenhasthehighesthydrogencontent.Theratioofyieldstrengthofhydrogenchargedandunchargedspecimenschangeswithhydrogenchargingtime,asshowninFig.1Itcanbeseenthattheyieldstrengthofhydrogenchargedspecimendecreasewithincreasinghydrogenchargingtime.Atthesamechargingtime,theyieldstressdecreasestheleastinthesecondpeak-agedstate,anddecreasesthemostintheunderagedstate.Itindicatesthattheunderagedspecimenismostsensitivetohydrogeninducedsoftening,whichisconsistentwiththeresultsofanotherhighstrengthaluminumalloy[6].TherelativechangesoftheradioofreductionofareawithhydrogenchargingtimearesummarizedinFig.2,whereΨ￣0andΨ￣Harethepercentagereductionofareaofthesamplewithoutandwithhydrogenchargingrespectively.Theradioofreductionofareareduceswhenhydrogenchargingtimeincreases,andthedecreasingdegreeofreductionofareaincreaseswithincreasingagingtime,ie,,theunderagedstateisthemostsensitivetohydrogenembrittlement.4.DiscussionItisknownfromtheresultsabovethatcathodicalchargingwithhydrogenleadstotheobviousdecreaseinthetensilestrengthandplasticityThisisbecausealargeamountofsolidsolutionhydrogenentersthespecimenintheprocessofhydrogenchargingSolidsolutionhydrogenisliabletoenterthecentreofdislocationundertheactionofdislocationtrap,henceraisingthemovabilityofdislocation.Thereforethedislocationsinhydrogenchargedspecimenmoveeasierthaninunchargedspecimen.soresultinginthereductionofyieldstrength[7].Whendislocationstartstomove,thecrystallatticeresistance(P-Nforce)whichitmustovercomeisgivenby:whereμismodulusofshear,visPoissonratio,aisspanofslipplane,bisatomspanofslipdirection.Moreover.theotherresistanceofdislocationmotionmayarisefromtheelasticinteractionofdislocation,theactionwithtreedislocationandetc.,itcanbeexpressedasfollows:whereαisconstant,XisdislocationspanSotheresistanceofdislocationmotioncanbewrittenasfollows:Becausehydrogenatomsreducetheatombondingstrengthafterhydrogencharging,shearmodulusμdecreasesandresultsinthereductionoff,therebytheyieldstressdecreases.Asthecentreofdislocationistheseriousdistortionzoneoflattice.thestresscanberelaxedafterhydrogenatomstuffing,andthesystemenergydecreases.Thusthecentreofdislocationisastrongtrapofhydrogen[8].Therefore,amovabledislocationcaptureshydrogenandmigratestograinboundaries.phaseboundariesorsurfaceofthespecimen,promotingthecrackiesformationandgrowth,thuscausingthelossofplasticity.Sincethelocalenrichmentofhydrogenisrealizedbydislocationtransporting(inthestageofdeformation),thelargerthereductionofyieldstress.theearlierarehydrogenatomstransportedtotheplaceofenrichment.Inaddition,thedamageofatombondingstrengthinducedbyhydrogenmakesthefracturestressdecrease[9]:whereCHishydrogenconcentration.σ_thisfracturestrengthbeforehydrogenchargingandisfracturestrengthafterhydrogencharging.Eq.(4)showsthatthematerialsmaybefracturedatalowerstraini.e.,brittlefractureoccurs.5.Conclusions(1)Hydrogencontentofdifferentlyagedspecimensincreaseswithincreasinghydrogenchargingtimethecapabilityofthealloytoabsorbhydrogeninunderagedstateisthestrongest.(2)Theyieldstressaswellasthepercentagereductionofareaof7175aluminumalloydecreaseashydrogenchargingtimeincreasesundervariousagedstates.(3)Underagedstateismostsensitivetohydrogeninducedsofteningandhardening.(4)Anexplanationwasofferedforthephenomenonofhydrogeninducedsofteninginthestageofdeformation,andhardeninginthestageoffracture.REFERENCES｜｜1G.KKock,Corrosion35(1979)73.2M.K.TsengandH.LMarcus,Scr.Metall.15(1981)427.3PSFao.M.GaoandR.P.Wei,Scr.Metall.19(1985)265.4R.G.SongandM.K.TsengJ.NortheasternUniversity15(1994)5(inChinese).5R.K.Viswanadham,T.S.sunandJ.A.S.Green,Metall.Trans.11A(1980)85.6J.Liu,M.KTsengandB.R.Liu.NonferrousMiningandMetallrgy5(1989)33(inChinese).7LChen,WXChen,ZHLiuandZ.Q.Hu,InFrocofthe1stNationalConfonAl-LiAlloys(Sheryang.China,1991)p.328(inChinese).8Z.HLiuL.ChenW.XChenY.X.ShaoandZ.Q.Hu,InProc.ofthe1stNationalConfonAl-LiAlloys(Shenyang,China,1991)p.334(inChinese).9R.A.OrianiandF.H.Josephic,ActaMetall.22(1974)1065.##61G.KKock,Corrosion35(1979)73.2M.K.TsengandH.LMarcus,Scr.Metall.15(1981)427.3PSFao.M.GaoandR.P.Wei,Scr.Metall.19(1985)265.4R.G.SongandM.K.TsengJ.NortheasternUniversity15(1994)5(inChinese).5R.K.Viswanadham,T.S.sunandJ.A.S.Green,Metall.Trans.11A(1980)85.6J.Liu,M.KTsengandB.R.Liu.NonferrousMiningandMetallrgy5(1989)33(inChinese).7LChen,WXChen,ZHLiuandZ.Q.Hu,InFrocofthe1stNationalConfonAl-LiAlloys(Sheryang.China,1991)p.328(inChinese).8Z.HLiuL.ChenW.XChenY.X.ShaoandZ.Q.Hu,InProc.ofthe1stNationalConfonAl-LiAlloys(Shenyang,China,1991)p.334(inChinese).9R.A.OrianiandF.H.Josephic,ActaMetall.22(1974)1065.##A##BINVESTIGATION OF HYDROGEN INDUCED DUCTILE BRITTLE TRANSITION IN 7175 ALUMINUM ALLOY$$$$R.G.Seng: B.J Zhong, MG. Zeng and P. Geng(Department of Materials Scierce, Science College,Northearstern Univeisity, Shenyang 110006, China Maruscript received 4 September 1995 in revised form 20 April 1996)Abstrac:Effects of hydrogen on the mechanical properties of differently aged 7175 aluminum alloys were investigated by using cathodic H-permeation, slow strain rate tension and so on. The results indicate that both the yield stress and the percentage reduction of area decrease with increasing hydrogen charging time, and the degree of reduction decreases as aging time increases for the same hydrogen charging time.
关键词:
:hydrogen induced ductile-brittle transition
,
null
,
null
,
null
苏琳琳
,
关桂霞
,
赵海盟
,
谭翔
,
徐振亮
,
吕书强
,
马蔼乃
,
晏磊
影像科学与光化学
doi:10.7517/j.issn.1674-0475.2016.01.059
针对当前地震云研究中只能利用长期以来的经验进行目视解译,无法形成系统的研究理论和研究模型的现状,结合目前流行的Android便携式设备,提出在Android平台上对地震云图像进行轮廓提取与匹配的研究思路.采用抗噪性能较好的数学形态学算法,在此基础上得到一种改进算法以提取出感兴趣区域,进而通过构造10个新的不变矩对Hu矩匹配算法进行改进,进行轮廓匹配,识别出地震云图像.在Android平台上则利用NDK(Native Delelopment Kit)通过JNI(Java Native Interface)调用OpenCV库函数,用C++语言实现改进算法.实验结果表明:该方法能够有效地识别时间序列下的地震云,正确率高,并且在Android平台上操作简单方便,为地震云预测地震提供初步研究基础和研究依据.
关键词:
地震云
,
轮廓提取
,
轮廓匹配
,
数学形态学
,
Hu矩
,
Android
钢铁
越来越多的企业认识到共同担负环境保护职责的重要性,诸如气候变化之类的全球环境问题已经成为钢铁工业能否保持竞争力的关键因素.在过去的世纪里,钢铁企业把环境治理的重心放在末端治理上,通过减少废物排放和提高副产品的循环率来减少工业活动对环境的影响.现在则通过努力开发环境友好的生产工艺,以节约能源、减少废物排放,最终达到降低生产成本的目的.POSCO已经为完成下一代钢铁工业的技术革命作了大量的工作,包括开发全新的炼铁工艺-FINEX,由于取消了烧结和炼焦过程,FINEX可以明显降低工艺消耗和空气污染物排放.与此同时,公司继续实施节能措施和加强末端治理,在2002年,Po-hang和Gwangyang厂开始增设干熄焦设备.为了减少烧结过程的粉尘、SOx、NOx和残留有机污染物的排放,Pohang厂正在建设装备活性焦塔的废气处理设备,预计在2004年4月投入使用.通过技术上的不断突破,钢铁工业将在保持增长的同时照顾到经济和环境的同步改善.
关键词:
钢铁工业
,
环境保护
,
FINEX
,
薄带连铸
张黛
,
范慧俐
,
徐晓伟
,
李永寿
,
李玉萍
人工晶体学报
doi:10.3969/j.issn.1000-985X.2003.01.015
采用氮气加压加温方法,以KBH4和NH4Cl为原料,通过在相同的温度、压力条件下,向反应体系中添加和不添加少量Li3N的对比实验,研究Li3N在KBH4和NH4Cl生成BN反应中的作用.反应产物中有无hBN和cBN生成是依据反应产物的X射线衍射图谱(XRD)和傅立叶变换红外光谱(FTIR)中有无hBN和cBN物相出现确认的.谢乐公式被用于估算生成的BN的粒径.结果表明,在650℃、7MPa的反应条件下,以KBH4和NH4Cl为原料没有生成BN的反应发生.但当在原料中加入Li3N后,反应产物中有大量hBN和少量cBN生成,其中hBN的平均颗粒尺寸约为14nm.分析确认,Li3N在上述由KBH4和NH4Cl合成hBN和cBN的反应中起催化作用.而且加入Li3N后,由KBH4和NH4Cl合成BN的反应压力和时间都明显低于Hu等人的相关报道结果.
关键词:
热气压法
,
合成
,
氮化硼
,
氮化锂
,
催化作用
