Iyini i-duplex insimbi engagqwali
I-Duplex insimbi engagqwali ibizwa ngokuthi "i-duplex" ngoba i-microstructure yayo ye-metallographic iqukethe izinhlobo ezimbili zezinhlamvu zensimbi, i-ferrite ne-austenite. Uma insimbi engagqwali eyi-duplex incibilika, iqala iqine ibe isakhiwo esiphelele se-ferrite lapho iqina isuka esimweni soketshezi. Njengoba i-material iphola ekamelweni lokushisa, cishe ingxenye yezinhlamvu ze-ferrite ishintsha ibe izinhlamvu ze-austenite. Ngenxa yalokho, cishe i-50% ye-microstructure iqukethe isigaba se-austenite futhi i-50% iqukethe isigaba se-ferrite.
Amandla ensimbi engagqwali e-duplex cishe aphindwe kabili kunawe-austenitic stainless steel evamile noma i-ferritic stainless steel. Ngakho-ke, abaklami banganciphisa ubukhulu bezindonga ezincane ezinhlelweni ezithile zokusebenza. Isibalo esilandelayo siqhathanisa amandla okukhiqiza ama-duplex stainless steels ambalwa kanye nensimbi engagqwali engu-316L austenitic ebangeni lokushisa legumbi ukuya ku-300 ℃. Nakuba izinsimbi ezingenasici eziyi-duplex zinamandla amakhulu, zibonisa ubupulasitiki obuhle nokuqina. Ukuqina nokudumba kwensimbi engagqwali eyi-duplex kungcono kakhulu kunaleyo yensimbi engagqwali ye-ferritic ne-carbon steel, futhi igcina ukuqina okuhle ngisho nakumazinga okushisa aphansi kakhulu afana -40 ℃/F. Kodwa namanje ayikwazi ukufinyelela izinga elihle kakhulu lensimbi engagqwali ye-austenitic.
Ukumelana nokugqwala kwensimbi engagqwali ikakhulukazi kuncike ekwakhekeni kwamakhemikhali. Ezimweni eziningi ezisetshenziswayo, insimbi engagqwali eyi-duplex ibonisa ukumelana nokugqwala okuphezulu ngenxa yokuqukethwe kwayo okuphezulu kwe-chromium, enenzuzo kuma-oxidizing acid, namanani anele e-molybdenum ne-nickel ukumelana nokugqwala emithonjeni ye-asidi eyehlisa okumaphakathi.
Ikhono le-duplex yensimbi engagqwali ukumelana ne-chloride ion pitting kanye nokugqwala kwe-crevice lincike ku-chromium, i-molybdenum, i-tungsten, kanye nokuqukethwe kwe-nitrogen. Okuqukethwe okuphezulu kwe-chromium, i-molybdenum, kanye ne-nitrogen yensimbi engagqwali eyi-duplex kuzinikeza ukumelana okuhle kakhulu ne-chloride pitting kanye nokugqwala kwemifantu. Banohlu lwezindawo ezihlukene zokumelana nokugqwala, kusukela kumabanga alingana no-316 ensimbi engagqwali ukumelana nokugqwala, njengensimbi engagqwali engu-2101 eyongayo, kuya kumamaki alingana no-6% we-molybdenum engagqwali ukumelana nokugqwala, njenge-SAF2507.
Insimbi engagqwali yesigaba esikabili inokumelana okuhle kakhulu ne-stress corrosion cracking (SCC), ezuzwa njengefa ohlangothini lwe-ferrite. Zonke izinsimbi ezingenasici eziyi-duplex zinokumelana okungcono kakhulu nokuqhekeka kokugqwala kwe-chloride kune-300 series austenitic stainless steels. Amabanga ajwayelekile ensimbi engagqwali ye-austenitic afana no-304 no-316 angase abhekane nokuqhekeka kokugqwala kwengcindezi ngaphansi kwezimo zama-ion e-chloride, umoya oswakeme, namazinga okushisa aphakeme. Ngakho-ke, ekusetshenzisweni okuningi embonini yamakhemikhali lapho kunobungozi obukhulu bokugqwala kokucindezeleka, insimbi engagqwali ye-duplex ivame ukusetshenziswa esikhundleni se-austenitic stainless steel.
Phakathi kwe-austenitic stainless steel ne-ferritic stainless steel, kodwa eduze ne-ferritic stainless steel ne-carbon steel. Uma kuqhathaniswa namamaki e-austenitic ensimbi engagqwali anokumelana nokugqwala okufanayo, insimbi engagqwali eyi-duplex inokuqukethwe kwe-nickel ephansi kanye ne-molybdenum. Ngenxa yokuqukethwe okuphansi kwezinto ze-alloying, insimbi engagqwali eyi-duplex ingaba nenzuzo enanini, ikakhulukazi uma inkokhiso ye-alloy iphezulu. Ngaphezu kwalokho, ngenxa yamandla esivuno esikhulu sensimbi engagqwali eyi-duplex, usayizi wayo we-cross-sectional ngokuvamile ungancishiswa. Uma kuqhathaniswa nokusebenzisa insimbi engagqwali ye-austenitic, ukusebenzisa insimbi engagqwali eyi-duplex kunganciphisa kakhulu izindleko nesisindo.
Insimbi engagqwali yesigaba esikabili inomlando weminyaka engaphezu kwengama-80. Amabanga okuqala kwakungama-alloys e-chromium, nickel, ne-molybdenum. Iqoqo lokuqala lensimbi engagqwali efojiwe negoqiwe yakhiqizwa eSweden ngo-1930 futhi yasetshenziswa embonini yephepha le-sulfite. Lawa mabanga athuthukiswe ukuze kuncishiswe izinkinga zokugqwala kwe-intergranular ekuqaleni kwe-carbon high austenitic stainless steel. Ngo-1930, iFinland yakhiqiza i-duplex yensimbi engagqwali. Umanduleli we-Uranus 50 wayenelungelo lobunikazi eFrance ngo-1936. Ngemva kweMpi Yezwe II, i-AISI 329 insimbi engagqwali yaba yibanga elivuthiwe futhi yasetshenziswa kabanzi kumapayipi okushisa ukushisa ezitshalweni ze-nitric acid. I-3RE60 ingelinye lamabanga esizukulwane sokuqala se-duplex ensimbi engagqwali athuthukiswe ngokukhethekile ukuthuthukisa ukumelana nokuqhekeka kwe-chloride stress corrosion (SCC). Kamuva, womabili amamaki ensimbi engagqwali efojiwe nawenziwe nge-cast duplex asetshenziswa ezimbonini ezihlukahlukene zokucubungula, okuhlanganisa iziqukathi, izinto ezishintsha ukushisa, namaphampu.
Isizukulwane sokuqala se-duplex insimbi engagqwali inokusebenza okuhle, kodwa inemikhawulo esimweni esishiselwe. Indawo ethintekile ekushiseni (HAZ) ye-weld seam inokuqina okuphansi ngenxa ye-ferrite eyeqile, futhi ukumelana kwayo nokugqwala kuphansi kakhulu kunokwesisekelo sensimbi. Le mikhawulo ikhawulela ukusetshenziswa kwesizukulwane sokuqala se-duplex yensimbi engagqwali ezinhlelweni ezithile ezithile ezifundazweni ezingashiselwe. Ukusungulwa kwenqubo yokucwenga insimbi engagqwali kanye nenqubo ye-argon oxygen decarburization (AOD) ngo-1968 yenza kwaba nokwenzeka ukukhiqiza uchungechunge lwamamaki ensimbi engagqwali. Enye yentuthuko eminingi elethwa yi-AOD ukwengezwa ngamabomu kwe-nitrogen njengengxenye ye-alloying. Ukwengeza i-nitrogen ensimbi engagqwali eyi-duplex kungenza ukuqina nokumelana nokugqwala kwe-HAZ endaweni eshiselwe eduze nezakhiwo zesisekelo. Ngokuthuthuka kokuzinza kwe-austenite, i-nitrogen ibuye yehlise izinga lokubunjwa kwezigaba eziyingozi ze-intermetallic. I-nitrogen equkethe i-duplex insimbi engagqwali ibizwa nge-second-generation duplex steel stainless. Le nqubekelaphambili entsha yezentengiselwano yaqala ngasekupheleni kweminyaka yawo-1970, ihambisana nokuthuthukiswa kwezizinda zikawoyela negesi zasolwandle eNorth Sea kanye nesidingo semakethe yensimbi engagqwali ekwazi ukumelana nokugqwala kwe-chloride ion, ukusebenza kahle kokucubungula, namandla aphezulu. I-2205 isibe yibanga eliyinhloko lesizukulwane sesibili sensimbi engagqwali ye-duplex futhi isetshenziswa kakhulu kumapayipi okuqoqa igesi yesikhulumi sikawoyela nezindawo zokucubungula. Ngenxa yamandla aphezulu ale nsimbi, ukushuba kodonga kungancishiswa, ngaleyo ndlela kuncishiswe isisindo sepulatifomu. Ngakho-ke, ukusetshenziswa kwale nsimbi engagqwali kunesikhanga esikhulu.
Insimbi engagqwali yesigaba esikabili ihlanganisa uchungechunge lwamamaki anezici ezihlukene zokumelana nokugqwala, futhi ukumelana nokugqwala kwayo kuncike ekwakhekeni kwengxubevange yazo. Ngokusho kokumelana nokugqwala, insimbi yesimanje eyi-duplex ihlukaniswe izigaba ezinhlanu:
1. Insimbi engagqwali ye-duplex yezomnotho ngaphandle kokwengeza ngamabomu i-molybdenum, njenge-2304;
2. Insimbi engagqwali ye-duplex yezomnotho equkethe i-molybdenum, njenge-S32003;
Insimbi engagqwali eyi-duplex ejwayelekile enokuqukethwe kwe-Cr okungaba ngu-22% kanye nokuqukethwe kwe-Mo okungu-3%, okufana no-2205, iyibanga eliyinhloko, elibalelwa cishe ku-60% wokusetshenziswa kwensimbi engagqwali eyi-duplex;
3. Insimbi engagqwali eyi-Super duplex enokuqukethwe kwe-Cr okungaba ngu-25% kanye nokuqukethwe kwe-Mo okungu-3%, ngevelu ye-PREN engu-40-45, njenge-2507; 5. Insimbi engagqwali eyi-Super duplex enokuqukethwe okuphezulu kwe-Cr ne-Mo kune-super duplex stainless steel, inani le-PREN elikhulu kuno-45, njenge-S32707
Ukumelana nokugqwala kwendawo kwensimbi engagqwali kuhlotshaniswa kakhulu nokuqukethwe kwe-alloy element. Izakhi ezingandisa ukumelana nokugqwala kwemigodi ngokuyinhloko i-Cr, Mo, kanye no-NW Nakuba u-W engavamile ukusetshenziswa, umnikelo wawo ophumelelayo ungaba ingxenye ye-Mo (ngephesenti lesisindo). Ubudlelwano phakathi kokumelana komgodi okuhlobene kwensimbi engagqwali esixazululweni se-ion ye-chloride kanye nokwakheka kwensimbi engagqwali bungachazwa nge-equation ye-empirical ebizwa ngokuthi inombolo elinganayo yokumelana ne-pitting (PREN). Ifomula yokubala ye-PREN ye-austenitic stainless steel ne-duplex stainless steel imi kanje: PREN (pitting corrosion equivalent)=% Cr+3.3 (% Mo+0.5% W)+16% N
Ngokuvamile kunenkolelo yokuthi ukusebenza okuhle kungafinyelelwa lapho isilinganiso sesigaba se-ferrite nesigaba se-austenite ku-duplex yensimbi engagqwali singama-30% kuya ku-70%. Kodwa-ke, insimbi engagqwali eyi-duplex ivame ukubhekwa njengenezilinganiso ezilinganayo ze-ferrite ne-austenite. Emkhiqizweni wamanje wezohwebo, ukuze kuzuzwe ukuqina okuphelele nezici zokucubungula, ingxenye ye-austenite ivame ukuba phezulu kancane. Ukusebenzisana phakathi kwezakhi eziyinhloko ze-alloying, ikakhulukazi i-chromium, i-molybdenum, i-nitrogen, ne-nickel, kuyinkimbinkimbi kakhulu. Ukuze uthole isakhiwo se-biphasic esizinzile esivumelana nokucubungula nokukhiqizwa, kuyadingeka ukunaka okuqukethwe okufanele kwe-elementi ngayinye.
Ngokungeziwe ekulinganeni kwesigaba, inkinga yesibili enkulu mayelana ne-duplex stainless steel kanye nokwakheka kwayo kwamakhemikhali ukwakheka kwezigaba eziyingozi ze-intermetallic emazingeni okushisa aphakeme. Isigaba sika-σ kanye no-χ kwakheka nge-chromium ephezulu kanye nensimbi engagqwali ye-molybdenum, futhi ngokukhethwayo kunciphe esigabeni se-ferrite. Ukwengezwa kwe-nitrogen kubambezele kakhulu ukwakheka kwalezi zigaba. Ngakho-ke, kubaluleke kakhulu ukugcina inani elanele le-nitrogen esixazululweni esiqinile. Ngokuhlangenwe nakho okwandayo ekukhiqizeni i-duplex stainless steel, abantu baya ngokuya beqaphela ukubaluleka kokulawula uhla oluncane lwezingxenye.
Ibanga lokuqala lokuqamba le-2205 duplex stainless steel (UNS S31803) belilibanzi kakhulu. Okuhlangenwe nakho kubonise ukuthi ukuze kuzuzwe ukumelana nokugqwala okuphelele futhi kugwenywe ukwakheka kwezigaba ze-intermetallic, okuqukethwe kwe-chromium, i-molybdenum, ne-nitrogen ye-S31803 kufanele kugcinwe emikhawulweni ephezulu naphakathi yohlu lokuqukethwe. Lokhu kuholele ekwethulweni kwe-2205 duplex steel UNS S32205 ethuthukisiwe enobubanzi obuncane bokuqamba. Ukwakhiwa kwe-S32205 kufana nensimbi engagqwali engu-2205 eyenzelwe ukuhweba namuhla.
Iyini i-2205 duplex steel stainless
I-2205 duplex insimbi engagqwali iyi-(austenitic ferritic) insimbi engagqwali eyi-duplex eyakhiwe ngo-22% we-chromium, u-3% we-molybdenum, kanye no-4.5% we-nickel nitrogen alloy (okubizwa ngokuthi i-2205 duplex steel). Esakhiweni saso sesixazululo esiqinile, izigaba ze-ferrite ne-austenite zenza cishe ingxenye ngayinye, futhi okuqukethwe kwesigaba esincane ngokuvamile kudinga ukufinyelela ku-30%. Ngakho-ke, inezici zokusebenza kokubili i-ferrite ne-austenitic insimbi engagqwali. I-2205 duplex steel stainless steel iyi-nitrogen doped duplex stainless steel enamandla amakhulu, ukuqina komthelela omuhle, kanye nokumelana nokugqwala okuhle kakhulu kwendawo yonke kanye nendawo. Insimbi eyi-duplex engu-2205 ifaneleka ngokukhethekile ebangeni lokushisa elingu-50 ° F/+600 ° F. Izinhlelo zokusebenza ezingaphezu kwalolu banga lokushisa zingacabangela le ngxubevange.
Isici esiyinhloko se-2205 duplex insimbi engagqwali ukuthi amandla ayo okukhiqiza angafinyelela ku-400-550MPa, okuyisilinganiso esiphindwe kabili kunesensimbi evamile ye-austenitic. Lesi sici sivumela abaklami ukuthi banciphise isisindo lapho beklama imikhiqizo, ngaleyo ndlela basindise izinto. Le alloy inenzuzo yenani ngaphezu kwe-316317L futhi inciphisa izindleko zokukhiqiza imishini. Mayelana nokumelana nokugqwala, ikakhulukazi ngaphansi kwezindawo ezimaphakathi ezinokhahlo njengamanzi olwandle ane-ion ephezulu ye-chloride, ukumelana nokugqwala komgodi, ukugqwala kwe-crevice, ukugqwala kwengcindezi, nokukhathala kokugqwala kwensimbi engagqwali e-duplex kungcono kakhulu kunokwensimbi evamile ye-austenitic, futhi ingafaniswa nensimbi engagqwali ye-austenitic ephezulu. Ngenxa yezici zokusebenza ezikhethekile ze-2205 duplex steel, izinhlobo zomkhiqizo zifaka ibha, ucingo, ipayipi elishiselwe, ipayipi elingenamthungo, ipuleti lensimbi, izinto ezibunjiwe, umugqa, njll. Inezinhlobonhlobo zezicelo futhi kuseyibanga elisetshenziswa kakhulu. ngensimbi ye-duplex.
Izakhiwo ezingokomzimba nezomshini ze-2205 duplex insimbi engagqwali
Ukuminyana: 8.0g/cm3. Amandla okuqina: σ b ≥ 620Mpa. Amandla esivuno: σ 0.2 ≥ 450Mpa, izinga le-elongation: δ ≥ 25%.
Ukumelana nokugqwala kwe-2205 duplex insimbi engagqwali
Ukugqwala okufanayo: Ngenxa yokuqukethwe kwe-chromium (22%), okuqukethwe kwe-molybdenum (3%), nokuqukethwe kwe-nitrogen (0.18%) ye-2205 duplex steel, ukumelana nokugqwala kungaphezu kuka-316L no-317L ezindaweni eziningi.
Ukumelana nokugqwala kwendawo: Okuqukethwe kwe-chromium, i-molybdenum, ne-nitrogen ku-2205 duplex steel kuyenza imelane kakhulu nokugqwala okukhomba kanye nokugqwala kwemifantu ezixazululweni ze-oxidizing ne-acidic.
Ukumelana nokugqwala kwengcindezi: I-double phase microstructure ye-2205 duplex steel isiza ukuthuthukisa ukumelana nokuqhekeka kokugqwala kwensimbi engagqwali. Ngaphansi kwezimo ezithile zokushisa, ingcindezi, umoya-mpilo, kanye nezimo ze-chloride, i-austenitic stainless steel izoba ne-chloride stress corrosion. Ngenxa yobunzima bokulawula lezi zimo, ukusetshenziswa kwe-304L, 316L, ne-317L kunqunyelwe kulokhu. Ukumelana nokukhathala kokugqwala: Amandla aphezulu kanye nokumelana nokugqwala kwe-2205 duplex steel kuyinikeza izinga eliphezulu lokumelana nokukhathala kokugqwala. Imishini yokucubungula isengozini ezindaweni ezonakalisayo kanye nemijikelezo yokulayisha, futhi izici ze-2205 zifaneleka kakhulu kwizicelo ezinjalo.
Izinkambu zokufaka isicelo ze-2205 duplex stainless steel
Izindawo ezisetshenziswayo ze-2205 duplex steel: imvelo ye-chloride engathathi hlangothi, imboni yokuhluza, imboni ye-petrochemical kanye namakhemikhali, amapayipi ezokuthutha embonini yamakhemikhali, imboni kaphethiloli negesi yemvelo, imboni ye-pulp nephepha, imboni kamanyolo, imboni ye-urea, imboni kamanyolo we-phosphate, imvelo yamanzi olwandle, amandla kanye imboni yokuvikela imvelo, imboni elula kanye nemboni yokudla, okokusebenza kwemboni yokudla neyokwenza imithi, izingxenye zesakhiwo ezinamandla kakhulu, amapayipi ahamba ngaphansi kolwandle, umtshingo igesi desulfurization, infiltration desalination equipment, sulfuric acid plant, marine engineering fasteners, njll.
Njengohlobo olukhethekile lwensimbi, i-2205 iphakeme kunensimbi engagqwali evamile kukho kokubili ubulukhuni nokusebenza.