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1、碩士學(xué)位論文摘要作為機(jī)械零部件三種主要失效形式之一,腐蝕問題直接關(guān)系到國民經(jīng)濟(jì)各個(gè)領(lǐng)域。鑒于此,本文參考現(xiàn)今先進(jìn)耐蝕合金,通過向鎳合金中添加銅、鈦、鐵元素,設(shè)計(jì)了6種通用性Ni.Cr.Mo.Mx耐蝕合金。采用手工電弧爐熔煉,制備出Ni.cr-Mo.Mx耐蝕合金,并在1140℃保溫2.5h固溶處理。針對(duì)所制試樣,從浸蝕、電化學(xué)腐蝕和高溫氧化三個(gè)方面進(jìn)行耐蝕性能及其機(jī)理的研究。將所制合金分別在H2s04、HCl、混合酸(10%HCl+lO%HN03)及6%FeCl3溶液中進(jìn)行浸泡腐蝕試驗(yàn),試驗(yàn)溫度為90℃。結(jié)
2、果表明,合金的腐蝕速率隨著鹽酸酸濃度升高而上升;60%的硫酸腐蝕性最強(qiáng)。通過測(cè)定Ni.cr.Mo—Mx合金在不同濃度的硫酸、鹽酸以及6%FeCl3溶液中的陽極極化曲線,獲得不同成分的合金在相同電解質(zhì)中的極化曲線的腐蝕電位、腐蝕電流、致鈍電位及維鈍電流、塔菲爾斜率的倒數(shù)等的變化,對(duì)合金中所添加元素的耐蝕作用進(jìn)行了較全面地分析。結(jié)果表明,在硫酸中3%cu含量的合金耐蝕性最強(qiáng)。在鹽酸中,合金的耐蝕性隨著Cu含量的增加而減弱。Ti會(huì)增強(qiáng)合金耐氧化性介質(zhì)中的耐蝕性,減弱合金的耐還原性介質(zhì)腐蝕和耐點(diǎn)蝕的能力,F(xiàn)e會(huì)降
3、低合金耐氧化性和還原性介質(zhì)腐蝕的能力,會(huì)提高合金耐點(diǎn)蝕的能力。采用增重法在800℃研究了Ni.cr.Mo.Mx合金的抗高溫氧化性能。結(jié)果表明,此合金的氧化增重曲線符合對(duì)數(shù)規(guī)律。Cu會(huì)降低合金抗高溫氧化性能,Ti會(huì)提高合金耐高溫氧化性能。關(guān)鍵詞:鎳基耐蝕合金;Cu含量;浸蝕;電化學(xué)腐蝕;陽極極化;高溫氧化:氧化動(dòng)力學(xué)新型Ni.Cr-Mo.Mx耐蝕合金的研制及其性能研究AbstractAsoneofthreekindsoffailuremodesofthemechanicalcomponents,corros
4、ionofmetalsconnectswithallregionsofeconomydirectly.Therefbre,basedonthereferencingtonowadaysadvancecorrosionresistantalloys,sixschemesVersatileNi.Cr.Mo.Mxcorrosionresistanta110ysweredesignedandpreparedbymanualelectro.a(chǎn)rcfurnacesinthisthesis.A1loysweres01u
5、tion—treatedat1140℃for2.5h.Corrosionresistanceandmechanismsofthesealloyswereresearchedthrougherosion,electrochemicalcorrosionandhightemperatureoxidation.Erosiontestofalloyswasperfb姍edinthes01utionsofsulphuricacid,hydrochloricacid,mixturalacid(10%HCl+10%HN
6、03)and6%FeCl3.Theresultsshowthattheallovasthecorrosionrateofincreaseofhydrochlorideacidconcentrationsincreased60percentofthemostcorrosivesulf.uricacid.Theanodicpolarizationcurvesindiff.erentelectrolytesolutionsweremeasuredbytheexperimentsofelectrochemical
7、corrosion.Theactionsofallelementsina110ywereanalyz9dbydiscoVeringthechangesofcorrosionpotentials,corrosioncurrentdensity,passivationpotentials,passiVationretainingcurrentdensityandslopeofTafelreciprocalindif托rentofalloysandindiff.erentelectrolytesolutions
8、.Theresultsshowthatthesulphuricacidcontentof3%Cualloycorrosionresistanceofthestrongest.Inhydrochloricacid,corrosionresistanceofthealIoywiththeincreaseinCuweakened.Ti.resistantalloyswillenhancetheoxidationofthemedium