Zvinokonzeresa uye matanho ekupikisa kwepickling corrosion ye304 Stainless simbi flanges

Abstract: Mutengi nguva pfupi yadarika akatenga batch ye304 Stainless steel flanges, iyo yaifanira kunyururwa uye kupfuudzwa isati yashandiswa. Nekuda kweizvozvo, mabubbles akaonekwa pamusoro pesimbi isina tsvina flanges mushure mekuiswa mutangi rekunhonga kweanopfuura maminetsi gumi. Mushure mekunge maflange abviswa uye acheneswa, ngura yakawanikwa. Kuti uwane chikonzero chekuora kwesimbi isina tsvina flanges, kudzivirira matambudziko emhando kubva kuitika zvakare, uye kuderedza kurasikirwa kwehupfumi. Mutengi akatikoka kuti timubatsire nekuongorora sampling uye metallographic inspection.

Chekutanga, rega ndiunze iyo 304 Stainless simbi flange. Iyo ine yakanaka corrosion resistance, heat resistance, uye yakaderera-tembiricha michina. Inoshingirira mukuora mumhepo uye inodzivirira acid. Inoshandiswa zvakanyanya mumapurojekiti epombi emvura akadai sepetroleum neindasitiri yemakemikari. Sechikamu chakakosha chekubatanidza pombi, ine zvakanakira kubatanidza nyore nyore uye kushandisa, kuchengetedza pombi yekuisa chisimbiso kuita, uye kufambisa kuongororwa nekutsiviwa kwechimwe chikamu chepombi.

Inspection process

1. Tarisa kuumbwa kwemakemikari: Chekutanga, edza iyo yakaora flange uye shandisa spectrometer kuona zvakananga kuumbwa kwayo kwemakemikari. Migumisiro inoratidzwa mumufananidzo uri pasi apa. Kuenzaniswa nezvinodiwa zvehunyanzvi zve304 simbi isina simbi yemakemikari kuumbwa muASTMA276-2013,iyo Cr yemukati mumakemikari eyakakundikana flange yakaderera pane yakajairika kukosha.

2. Metallographic inspection: A longitudinal cross-section sample yakachekwa panzvimbo yekuora yeflange yakakundikana. Mushure mekupenya, hapana ngura yakawanikwa. Non-metallic inclusions yakaonekwa pasi pemetallographic maikorosikopu uye sulfide chikwata chakarongwa se 1.5, chikwata chealuminium chakanzi 0, chikamu chemunyu cheasidhi chakanzi 0, uye chikamu che spherical oxide chakarongwa se 1.5; muenzaniso wacho wakadzikwa neferric chloride hydrochloric acid aqueous solution uye yakacherechedzwa pasi pe 100x metallographic microscope. Zvakaonekwa kuti austenite zviyo muzvinhu zvakanga zvisina kuenzana zvakanyanya. Saizi yegiredhi giredhi yakaongororwa zvinoenderana neGB/T6394-2002. Nzvimbo yakakora yezviyo inogona kuverengerwa se 1.5 uye nzvimbo yezviyo yakanaka inogona kuverengerwa se 4.0. Nokucherechedza microstructure ye-pedo-surface corrosion, inogona kuwanikwa kuti kuparara kunotanga kubva pamusoro pesimbi, kunoisa pamiganhu yezviyo austenite uye kunosvika mukati mezvinyorwa. Miganhu yezviyo munzvimbo iyi inoparadzwa nekuora, uye kusimba kwekubatana pakati pezviyo zvinenge zvapera zvachose. Iyo simbi yakanyanyisa yakasvibiswa inotoita hupfu, iyo inoputika nyore nyore pamusoro pezvinhu.

3. Kuongorora kwakazara: Mhedzisiro yekuedzwa kwemuviri uye kemikari inoratidza kuti iyo Cr yemukati mune kemikari yesimbi isina tsvina flange yakadzikira zvishoma pane yakajairika kukosha. Iyo Cr element ndiyo inonyanya kukosha chinhu chinotemesa corrosion kuramba kwesimbi isina tsvina. Inogona kuita neokisijeni kuburitsa Cr oxides, ichigadzira passivation layer kudzivirira ngura; iyo isiri-metallic sulfide yemukati mune iyo yakakwira, uye kuunganidzwa kwe sulfides munzvimbo dzeko kuchaita kuti kuderera kweCr concentration munzvimbo yakapoteredza, kuumba nzvimbo yeCr-varombo, nokudaro inokanganisa kushorwa kwesimbi isina tsvina; kucherechedza zviyo zvestainless simbi flange, zvinogona kuwanikwa kuti saizi yayo yezviyo haina kuenzana zvakanyanya, uye iyo isina kuenzana yakasanganiswa tsanga musangano inokonzeresa kuumba mutsauko mukugona kwe electrode, zvichikonzera micro-mabhatiri, izvo zvinotungamira kune electrochemical corrosion pa. pamusoro pezvinhu. Iyo yakaoma uye yakanaka yakasanganiswa tsanga dzesimbi isina simbi flange inonyanya kuenderana nekupisa kushanda deformation process, iyo inokonzerwa nekukurumidza deformation yezviyo panguva yekugadzira. Ongororo yeiyo microstructure yepedyo-pamusoro-soro corrosion yeflange inoratidza kuti iyo corrosion inotangira kubva kune iyo flange uye inoenda mukati ichitevedza austenite muganhu wezviyo. Iyo yakakwira-magnification microstructure yezvinhu inoratidza kuti kune zvimwe zvikamu zvechitatu zvakaderedzwa pamuganho wezviyo we austenite wezvinhu. Zvikamu zvechitatu zvakaunganidzwa pamuganhu wezviyo zvinowanzokonzera kuderera kwechromium pamuganho wezviyo, zvichiita kuti intergranular corrosion tendency uye kuderedza zvakanyanya kuramba kwayo.

Mhedziso

Mhedziso dzinotevera dzinogona kutorwa kubva kune zvakakonzera pickling corrosion ye304 Stainless simbi flanges:

1. Kuora kwesimbi isina tsvina flanges ndiyo mhedzisiro yekubatanidzwa kwechiito chezvikonzero zvakawanda, pakati peiyo chikamu chechitatu chakanaya pamuganhu wezviyo zvechigadzirwa ndicho chikonzero chikuru chekutadza kweflange. Zvinokurudzirwa kunyatso kudzora tembiricha yekudziya panguva yekushanda inopisa, kwete kudarika tembiricha yekumusoro yezvinhu zvekudziya maitiro, uye kutonhora nekukurumidza mushure mekugadzirisa kwakasimba kudzivirira kugara mutembiricha ye450 ℃ -925 ℃ kwenguva yakareba. kudzivirira kunaya kwechikamu chechitatu chezvikamu.
2. Mbeu dzakasanganiswa muzvinyorwa zvinowanzoitika kune electrochemical corrosion pamusoro pechinhu, uye chiyero chekugadzira chinofanira kunyatsodzorwa panguva yekugadzira.
3. Iyo yakaderera Cr yemukati uye yakakwira sulfide yemukati mune izvo zvinokanganisa zvakananga kushora kweiyo flange. Pakusarudza zvinhu, kutarisisa kunofanirwa kubhadharwa pakusarudza zvinhu zvine yakachena metallurgical quality.