材料期刊网

RELATIONSHIP BETWEEN FRACTAL DIMENSION AND CYCLIC CREEP PROPERTIES OF ROTOR STEEL 34CrMoA

YI Jianzhang Shenyang Institute of Aeronautical Engineering , Shenyang , ChinaYANG Zhi'an ZHU Shijie WANG Zhongguang Institute of Metal Research , Academia Sinica , Shenyang , China lecturer , Department of Safety Engineering , Shenyang Institute of Aeronautical Engineering , Shenyang 110031 , China

金属学报(英文版)

Vertical section method has been used to measure the fractal dimension of cyclic creep frac- ture surfaces of rotor steel 34CrMoA at 550℃.The relationship between fractal dimension and cyclic creep properties has been analyzed.The fractal dimension is dependent upon the power product of minimum creep rate and rupture time,and satisfies the linear function with rupture strain.

关键词: cyclic creep , null , null , null

QUANTITATIVE RELATION BETWEEN YIELD STRESS AND R-VALUE OF Ti PLATE ALONG PARALLEL AND PERPENDICULAR TO ROLLING DIRECTION

ZHANG Derong Shenyang Institute of Aeronautical Engineering , Shenyang , China ZHANG Derong Associate Professor.Dept.of Aeronautics , Shenyang Institute of Aeronautical Engineering , Shenyang 110031 , China

金属学报(英文版)

An attempt was made on the quantitative prediction of the relationship hetween the yield stress and R-value along the parallel and perpendicular to the rolling direction of Ti plate based on analysis of the previous experimental data.It is shown that the yield stress along one direction and another is quite synchronized with the R—value.According to the plasticity theo- ry,an formular of σ_(1s)/σ_(2s)=[(1+1/R_2)/(1+1/R_1)/~(1 2) was proposed,In statistic estima- tion.the calculated results are in good agreement with the experimental data.The availability of this formula was briefly discussed also.

关键词: titanium plate , null , null

The effect of environmental variables on atmospheric corrosion of carbon steel in Shenyang

Chinese Science Bulletin

A study was carried out in order to investigate the effect of contaminants and meteorological variables on the rust layer of carbon steel exposed in Shenyang urban atmosphere. Seven kinds of contaminants and twelve kinds of meteorological parameters were also registered in order to correlate the data with respect to corrosion rate and the stepwise multiple regression analysis was carried out in order to obtain the best regression model. The sum of rainfall time as well as sunshine time and the concentration of H(2)S could stimulate initial atmospheric corrosion of carbon steel. The initial atmospheric corrosion kinetics of carbon steel was observed to follow the cubic equation. The corrosion products were analyzed by XRD and the transformation of phases in different periods was discussed.

关键词: contaminants;meteorological parameters;carbon steel;urban atmospheric;corrosion;stepwise multiple regression;corrosion products;rust;pollution

The fourth editorial committee meeting of JMST was held in Shenyang, China

材料科学技术（英文）

关键词:

在碳钢墓材上激光熔覆玻璃涂层及其物理化学行为研究

喻家庆

腐蚀学报（英文）

在碳钢墓材上激光熔覆玻璃涂层及其物理化学行为研究喻家庆(中国科学院金属腐蚀与防护研究所九三届博士,沈阳110015)LASERCLADGLASSCOATINGSONSTEELSANDTHEIRPHYSICAL—CHEMICALBEHAVIORS$(AstractofDissertationforDoctorofEngineeringatInstituteofCorrosionandProtectionofMetals,TheChineseAcademyofSciences,Shenyang110015)b

关键词:

Characterisation of initial atmospheric corrosion carbon steels by field exposure and laboratory simulation

Corrosion Science

The early stages of the evolution of atmospheric corrosion of carbon steels exposed in both a laboratory simulated and a natural atmosphere environment in Shenyang have been observed by in situ scanning electron microscopy. In the case of laboratory cyclic wet-dry tests, even though the chloride content level is very low, filiform corrosion is initiated in the early stage. The filiform corrosion grows in random directions, forming a network of ridges. White nodules nucleate and grow on the ridges during continued corrosion and eventually connect with each other to form the initial corrosion scale. Pits were also found on the surface beneath corrosion products. In the case of a natural atmospheric environment, both filiform corrosion and other localized corrosion, such as pitting and inter-granular attack take place in the initial stage. It is obvious that there is variety of localized corrosion in the initial stage of atmospheric corrosion. (C) 2007 Elsevier Ltd. All rights reserved.

关键词: steel;atmospheric corrosion;initial stage;localized corrosion;in-situ;iron;electrolyte;thickness

CRYOGENIC MECHANICAL BEHAVIOUR OF MARAGING STEEL CONTAINING HYDROGEN

LIU Zhonghao CHEN Lian Institute of Metal Research , Academia Sinica , Shenyang , China

金属学报(英文版)

Within the range of 77 to 295 K,the strength and plastieity of 18Ni maraging steel increase with decreasing temperature and decrease with increasing hydrogen content.The susceptibility to hydrogen embrittlement of the maraged specimens is superior to solid solution ones.The dislocations after plastically deforming will tangle into dislocation cells which reduce thermselves in size as the temperature decreases,and coarsen as the hydrogen content in- creases.No cryogenie deformation twin was found.The tensile fracture surfaces of the solu- tion and maraged specimens containing 5.90 ppm hydrogen under 295 to 223 K are revealed as quasi-cleavage and intergranular features respectively and as transgranular ones under other experimental conditions.The influence of hydrogen on the mechanical behaviour of steel and the mechanism of hydrogen induced deformation and fracture are discussed. Research Assistant, Institute of Metal Research,Academia Sinica, Shenyang 110015,China

关键词: maraging steel , null , null , null

METALLOGRAPHIC STUDY ON SEGREGATION BEHAVIOUR OF P IN COLD-ROLLED Fe-P ALLOYS DURING ANNEALING

NING Hua ZHANG Lixin Institute of Corrosion and Protection of Metals , Academia Sinica , Shenyang , China

金属学报(英文版)

The segregation behaviour of P and its effect on structure of 70%-reduction cold rolled Fe-P alloys containing different contents of P,e.g.,0.007,0.06 and 0.09% P,during annealing at 200-700℃ under vacuum have been studied by means of metallography and EPMA.The P was found to segregate preferentially along dislocation line during recovery annealing.The P-riched dislocation densing region,the P-depleted region and the sub-grain-like boundary thus formed.The nuclei grow preferentially during recrystallization in such region that the P segregation is more evident and the residual strain by dislocation densing increases to large extent.After recrystallizing,the P segregates along grain boundaries and makes the grains in alloy fine. Engineer,Institute of Corrosion and Protection of Metals,Academia Sinica,Shenyang 110015,China

关键词: P , null , null , null

INVESTIGATION OF HYDROGEN INDUCED DUCTILE BRITTLE TRANSITION IN 7175 ALUMINUM ALLOY

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

EFFECT OF MAGNETIC FIELD ON CALCITONIN GENE-RELATED PEPTIDE IN PERIODONTAL LIG AMENTS OF RATS

X. Chang , K. Qin and Y.L.Lu Orthodontic Department of Stomatology College , China Medical University , Sheny ang 110001 , China

金属学报(英文版)

proach change of CGRP with time in periodontal ligaments of rats in magnetic field, maxillae of 28 Wistar rats of 6 7 weeks were placed in magnetic fields of permanent magnets Nd 2 Fe 4 B. Changes of CGRP with t ime in maxillary periodontal ligaments of the rats were studied by immunohistochemistry. The result showed that: magnetic field had dynamic effect and some promotional effect on recove?E F F E C T O F M A G N E T I C F I E L D O N C A L C I T O N I N G E N E- R E L A T E D P E P T I D E I N P E R I O D O N T A L L I G A M E N T S O F R A T S X. Chang , K. Qin and Y. L. Lu Orthodontic Department of Stomatology College , China Medical University , Shenyang 110001 , China Manuscript received 24 June 1999 In order to approach change of C G R P with tim e in periodontal liga m ents of rats in m agneticfield , m axillae of 28 Wistar rats of 6 7 weeks w ere placed in m agnetic fields of per m anentm agnets Nd 2 Fe4 B. Changes of C G R P with tim e in m axillary periodontal liga ments of therats were stu died by i m m unohistoche mistry . The result sho wed that : m agnetic field had dy na m ic effect an d so m e pro motional effect on recovering and reconstruction of the periodontaltissues in it . This provided a better theoretical evidence for clinical use of per m anent m agnets .

关键词: per m anent m agnet Nd 2 Fe4 B , null , null , null