項目六：鋼鐵分析任務(wù)四：鋼鐵中磷的測定鋼鐵中磷的測定方法介紹課程：工業(yè)分析中文Scenario6:SteelanalysisTask4:DeterminationofphosphorusinsteelIntroductiontothedeterminationmethodofphosphorusinsteelCourse:IndustrialAnalysisEglish一、鋼鐵中磷的作用鋼鐵中磷以固溶體、磷化鐵、其他合金元素的磷化物及少量磷酸鹽形式存在磷化鐵質(zhì)硬，影響塑性和韌性，易發(fā)生冷脆形象，凝結(jié)時會發(fā)生偏析磷能提高鋼材的抗腐蝕性，提高鋼材的拉伸強度中文一、TheroleofphosphorusinsteelPhosphorusinsteelexistsintheformofsolidsolutions,phosphidesofironphosphide,phosphidesofotherelements,andsmallamountsofphosphatesPhosphatedironishardandaffectsplasticityandtoughness,makingitpronetocoldbrittlenessandsegregationduringsolidificationPhosphoruscanimprovethecorrosionresistanceandtensilestrengthofsteelEglishP的主要氧化態(tài)為-3、+1、+3、+4、+5，相應(yīng)的典型化合物依次為PH3、H3PO2、H3PO3、H4P2O4、H3PO4PH3:無色而有劇毒的氣體，在水中溶解度小。PH3、H3PO2及其鹽類均是強還原劑，但與大多數(shù)氧化劑反應(yīng)緩慢；H4P2O4在水中很不穩(wěn)定能發(fā)生歧化反應(yīng)，生成H3PO3、H3PO4；H3PO4為不揮發(fā)性酸，由于其標(biāo)準(zhǔn)電極電位很低通常不具有氧化性。中文ThemainoxidationstateofPis

-3，+1，+3，+4or+5，andthecorrespondingtypicalcompoundsarePH3、H3PO2、H3PO3、H4P2O4、H3PO4PH3:acolorlessandhighlytoxicgaswithlowsolubilityinwater.PH3,H3PO2,andtheirsaltsarestrongreducingagents,butreactslowlywithmostoxidants;H4P2O4isveryunstableinwaterandcanundergodisproportionationreactions,generatingH3PO3andH3PO4;H3PO4isanon-volatileacidandusuallydoesnothaveoxidizingpropertiesduetoitslowstandardelectrodepotential.Eglish二、測定方法重量法分光光度法酸堿滴定法磷鉬酸銨法磷酸銨鎂法磷鉬酸銨-酸堿滴定法磷鉬酸喹啉-酸堿滴定法中文二、MeasurementmethodgravimetricmethodspectrophotometryAcid-basetitrationAmmoniummolybdate

phosphatemethodMagnesiumammoniumphosphatemethodAmmoniumphosphomolybdateacid-basetitrationmethodQuinolinephosphomolybdateacid-basetitrationmethodEglish1、重量法-磷鉬酸銨法樣品用酸分解成溶液測定過程強酸中磷酸與過量鉬酸銨形成磷鉬酸銨沉淀灼燒成P2O5·24MoO3,稱重第一步第二步第三步中文1、gravimetricmethod-Ammoniummolybdate

phosphateThesampleisdecomposedintoasolutionusingacidMeasurementprocessPhosphoricacidinstrongacidreactswithexcessammoniummolybdatetoformammoniummolybdateprecipitationBurntogenerateP2O5·24MoO3,weighstep1step2step3Eglish第三步樣品用酸分解成溶液測定過程第二步第一步氨性溶液中PO43-與Mg2+、NH4+形成磷酸銨鎂沉淀灼燒成焦磷酸鎂,稱重1、重量法-磷酸銨鎂法中文step3ThesampleisdecomposedintoasolutionusingacidMeasurementprocessstep2step1PO43-formsammoniummagnesiumphosphateprecipitationwithMg2+andNH4+inammoniasolutionBurntoformmagnesiumpyrophosphate,weigh1、gravimetricmethod-MagnesiumammoniumphosphateEglish2、分光光度法磷酸磷雜多酸磷鉬雜多藍(lán)磷鉬雜多酸磷釩鉬雜多酸分光光度法測定中文2、spectrophotometryphosphoricacidPhosphorusmolybdenumheteropolyPhosphorusmolybdenumheteropolybluePhosphorusmolybdenumheteropolyPhosphorusvanadiummolybdenumheteropolyacidDeterminationbyspectrophotometryEglish3、酸堿滴定法（1）磷鉬酸銨-酸堿滴定法磷磷鉬酸銨沉淀NH4+過量NaOH溶解沉淀酚酞為指示劑，用硝酸滴定過量NaOH中文3、Acid-basetitration（1）Ammoniumphosphomolybdateacid-basetitrationmethodphosphorusAmmoniumphosphomolybdateprecipitationNH4+AddexcessNaOHtodissolvetheprecipitateTitrateexcessNaOHwithnitricacidusingphenolphthaleinasanindicatorEglish（2）磷鉬酸喹啉-酸堿滴定法PO43-MoO42-H+H3(PO4.12MoO3).H2O磷鉬雜多酸C9H7N磷鉬酸喹啉黃色(C9H7N)3H3(PO4.12MoO3).H2O一定量過量水洗NaOH溶解，剩余NaOHHCl標(biāo)液滴定V有機堿喹啉中文（2）Quinolinephosphomolybdateacid-basetitrationmethodPO43-MoO42-H+H3(PO4.12MoO3).H2OPhosphorusmolybdenumheteropol