腐蝕與防護(hù)-課件

MaterialsCorrosionandProtection

1Instructor:Dr.JingMADepart.ofMetallicMaterialsEngineeringOffice:A344MaterialBuildingE-mail:majingt@BilingualTeachingDemandofeconomicglobalization.ChinaMinistryofEducation“BilingualTeachingCourseReformPlan”,2001Toimprovestudents’learningandacquiringofmakethemcompetentforinternationalcommunicationintheirspecialtyfields.Contentsofthesubject:Chapter1IntroductionChapter2ElectrochemistryFundamentals

Chapter3

GeneralandLocalCorrosionChapter4

NatureCorrosionChapter5OxidationChapter6CorrosionControl

(1)楊德鈞，沈卓身,金屬腐蝕學(xué).冶金工業(yè)版(2)

/mestijaya/cmm/CorrosionandcorrosioncontrolByR.WinstonRevie

很有用的網(wǎng)址：

http://bbsGoogle搜索：MITopencourse何業(yè)東，齊慧濱.材料腐蝕與防護(hù)概論.機(jī)械工業(yè)版

腐蝕源于拉丁文“corrdere”，意即“損壞”、“腐爛”Corrosioncanbedefinedasthedegradation

ofamaterial

duetoareaction

withitsenvironment.

材料與環(huán)境組分發(fā)生的物理的、化學(xué)和電化學(xué)作用而引起的變質(zhì)和破壞，稱之為腐蝕。

Materials

canbemetals,polymers(plastics,rubbers,etc.),ceramics(concrete,brick,etc.)orcompositesmechanicalmixturesoftwoormorematerialswithdifferentproperties.Chapter1

Questions:?Whatiscorrosion？

Questions:?WhyMetalscorrode？Metalscorrodebecauseweusetheminenvironmentswheretheyarechemicallyunstable.

mostmetals

arecommonly

intheformofvarious

chemicalcompounds(ores).Onlycopperandthepreciousmetals(gold,silver,platinum,etc.)arefoundinnatureintheirmetallicstate.smelting,refiningprocessescorrosionAllothermetalsareunstableandhaveatendencytoreverttotheirmorestablemineralforms.Somemetalsformprotectiveceramicfilms(passivefilms)ontheirsurfacesandtheseprevent,orslowdown,theircorrosionprocess.AnodizedtitaniumearringsThethicknessofthetitaniumoxideonthemetalsurfacerefractsthelightandcausestherainbowcolorsonherearrings.StainlesssteeleyeglassesThispassivefilmofonlyaboutadozenatomsthickcanbeprotective.1兵器：長期貯存，使用環(huán)境惡劣2交通運(yùn)輸：對鐵軌、機(jī)車的腐蝕，對飛機(jī)零部件的腐蝕；（超高強(qiáng)度鋁合金-應(yīng)力腐蝕）船舶的海水腐蝕；3能源電力：火電有鍋爐和管道的腐蝕，水電有水輪機(jī)組的腐蝕；核電站蒸汽發(fā)生器的腐蝕；（高鎳合金-晶間腐蝕）煤礦安全；（井下濕度大、磨損腐蝕）石油，油氣開采和運(yùn)輸造成設(shè)備和管道的腐蝕。4機(jī)械電子產(chǎn)品:機(jī)床、電器5化工設(shè)備：管道、鍋爐、儲存、閥門、冷凝；6建筑物:鋼筋混凝土的鹽害7民生：自來水管的銹蝕；8環(huán)境污染…UncontrolledcorrosionmayleadtodisastrousconsequencesLosscausedbycorrosion在化學(xué)工業(yè)、石油化工、造紙等工業(yè)中，金屬腐蝕造成設(shè)備的跑、冒、滴、漏可造成大量有毒的物質(zhì)泄漏，污染環(huán)境，危害人民的健康。因此，研究與解決材料的腐蝕問題，與防止環(huán)境污染、保護(hù)人民的健康息息相關(guān).每年由于腐蝕可使大約10～20％的金屬損失掉了。2003年世界的鋼產(chǎn)量達(dá)到9.625億噸，中國的鋼產(chǎn)量高達(dá)2.2億噸，美國的鋼產(chǎn)量為0.914億噸。按下限計(jì)算，世界每年腐蝕掉的鋼大于美國的鋼產(chǎn)量；中國一年就有2200萬噸鋼被腐蝕掉了，相當(dāng)于腐蝕掉一個(gè)大型鋼鐵企業(yè)的年產(chǎn)量。腐蝕事故舉例

1966年某天然氣井的套管發(fā)生硫化物應(yīng)力腐蝕開裂，造成井噴和特大爆炸，人員傷亡，日產(chǎn)百萬立方米的高產(chǎn)氣井報(bào)廢。1971年某天然氣管線發(fā)生腐蝕斷裂，產(chǎn)生爆炸，直接經(jīng)濟(jì)損失達(dá)7000萬元。1997年某化工廠年18個(gè)乙烯原料儲罐由于硫化物腐儲罐引起大火，停產(chǎn)半年，直接損失達(dá)2億多元，，間接損失巨大。1985年日本的一架波音747客機(jī)，由于應(yīng)力腐蝕斷裂，死亡500余人。塔里木油田某井油管CO2腐蝕形貌圖含硫輸氣管線沿著焊縫開裂失效按材料腐蝕形態(tài)均勻腐蝕不均勻腐蝕點(diǎn)蝕（孔蝕）縫隙腐蝕及絲狀腐蝕電偶腐蝕（接觸腐蝕）晶間腐蝕選擇性腐蝕局部腐蝕全面腐蝕ClassificationofcorrosionCharacterofcorrosionbreakage:UniformCorrosion

(generalCorrosion)Thesurfaceeffectproducedbymostdirectchemicalattacks(e.g.,asbyanacid)isauniformetchingofthemetal.GalvanicCorrosion電偶腐蝕Galvaniccorrosionisanelectrochemicalactionoftwodissimilarmetalsinthepresenceofanelectrolyteandanelectronconductivepath.Itoccurswhendissimilarmetalsareincontact.Pittingcorrosion（點(diǎn)蝕）Pittingcorrosionislocalizedcorrosionthatoccursatmicroscopicdefectsonametalsurface.Thepitsareoftenfoundunderneathsurfacedepositscausedbycorrosionproductaccumulation.CreviceCorrosion縫隙腐蝕Creviceorcontactcorrosionisthecorrosionproducedattheregionofcontactofmetalswithmetalsormetalswithnonmetals.Itmayoccuratwashers,atsandgrains,underappliedprotectivefilms（薄膜）,andatpocketsformedbythreadedjoints.FiliformCorrosion絲狀腐蝕Thistypeofcorrosionoccursonpaintedorplatedsurfaceswhenmoisturepermeatesthecoating.Longbranchingfilaments（細(xì)絲）ofcorrosionproductextendoutfromtheoriginalcorrosionpitandcausedegradationoftheprotectivecoating.IntergranularCorrosion

晶間腐蝕Intergranularcorrosionisanattackonor

adjacenttothegrainboundaries（晶界）

ofametaloralloy.StressCorrosionCracking

應(yīng)力腐蝕斷裂Stresscorrosioncracking(SCC)iscausedbythesimultaneouseffectsoftensilestress（拉應(yīng)力）andaspecificcorrosiveenvironment.Stressesmaybeduetoappliedloads,residualstressesfromthemanufacturingprocess,oracombinationofboth.CorrosionFatigue

腐蝕疲勞Corrosionfatigueisaspecialcaseofstresscorrosioncausedbythecombinedeffectsofcyclicstress（循環(huán)應(yīng)力）andcorrosion.Nometalisimmunefromsomereductionofitsresistancetocyclicstressingifthemetalisinacorrosiveenvironment.FrettingCorrosion

微動腐蝕Therapidcorrosionthatoccursattheinterfacebetweencontacting,highlyloadedmetalsurfaceswhensubjectedtoslightvibratorymotionsisknownasfrettingcorrosion.ErosionCorrosion磨損腐蝕Erosioncorrosionistheresultofacombinationofanaggressive（侵蝕性）chemicalenvironmentandhighfluidsurfacevelocities.Dealloying

脫合金成分腐蝕Dealloyingisarareformofcorrosionfoundincopperalloys,graycastiron,andsomeotheralloys.Dealloyingoccurswhenthealloylosestheactivecomponentofthemetalandretainsthemorecorrosionresistantcomponentinaporous“sponge”（海綿）onthemetalsurface.HydrogenDamage氫損傷Hydrogenembrittlementisaproblemwithhighstrengthsteels,titanium,andsomeothermetals.Controlisbyeliminatinghydrogenfromtheenvironmentorbytheuseofresistantalloys.MicrobialCorrosion微生物腐蝕Microbialcorrosion(alsocalledmicrobiologically-influencedcorrosionorMIC)iscorrosionthatiscausedbythepresenceandactivitiesofmicrobes（微生物）.Thiscorrosioncantakemanyformsandcanbecontrolledbybiocides（殺菌劑）orbyconventionalcorrosioncontrolmethods.ConcentrationCell

Corrosion濃差電池腐蝕Concentrationcellcorrosionoccurswhentwoormoreareasofametalsurfaceareincontactwithdifferentconcentrationsofthesamesolution.CorrosioninConcrete

混凝土腐蝕Concreteisawidely-usedstructuralmaterialthatisfrequentlyreinforcedwithcarbonsteelreinforcingrods（鋼筋）,post-tensioningcableorprestressingwires.Thesteelisnecessarytomaintainthestrengthofthestructure,butitissubjecttocorrosion.ClassificationofcorrosionAccordingtocorrosionenvironments(腐蝕環(huán)境)Acorrosioninnatureenvironments(自然環(huán)境中的腐蝕)大氣腐蝕、淡水和海水腐蝕、土壤腐蝕、細(xì)菌腐蝕Bcorrosioninindustrialenvironments(工業(yè)環(huán)境介質(zhì)中的腐蝕)在酸性溶液中、堿性溶液中、鹽類溶液、工業(yè)水、熔鹽中的腐蝕。腐蝕分類Accordingtocorrosionmechanism(