Q. C. Le and J. Z. Cui School of Materials & Metallurgy
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Northeastern University
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Shenyang 110006
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China
金属学报(英文版)
The 08 Al steel sheets were hot dip ped into Zn - Mn bath with 0 1 % Mn and 0 2 % Mn at600 ～420 ℃ bath tem perature , and then w ere treated in different w ays . The after - treat ments include cooling in the air at room tem perature directly , holding at the upper part of thehot dip galvanizing furnace for 60 s an d then holding at 510 ±10 ℃for 90 s . The results in dicated that blue , yellow , and purple , w hose coloration varied with the co m position an d thetem perature of bath and the w ays of after - treat ment . Finally , the mechanism of coloredzinc coating w as discussed .
关键词:
coloring hot dip galvanization
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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
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
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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:
铁军
腐蚀学报（英文）
铝电解阴极过程的电化学研究铁军(东北大学有色金属冶炼九四级博士研究生,沈阳110006)综合评述了铝电解阴极过程中铝沉积和再溶解损失的研究现状根据高温下液态金属铝与各种金属和石墨材料相作用的特性,选择金属钨作为工作电极和参比电极,用电化学方法(循环伏安法、方波电流法、换向电流法、计时电流法和计时电位法)研究了Na3AlF6-NaF、CaF2-MgF2-Alf3、纯冰晶石、工业电解质、低熔点铝电解质溶液中铝的电解沉积和溶解损失过程?...
关键词:
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
LIU Zhonghao CHEN Lian Institute of Metal Research
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Academia Sinica
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Shenyang
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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
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NING Hua ZHANG Lixin Institute of Corrosion and Protection of Metals
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Academia Sinica
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Shenyang
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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
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