Hlokomela hore ha se liphekolo tsohle tsa mocheso oa post weld tse molemo

01 Khetho ea mokhoa oa ho phekola mocheso

Phello ea ka mor'a tjheseletsa mocheso kalafo ka tensile matla le creep moeli oa tšepe e amana le mocheso le ho tšoara nako ea kalafo mocheso. Phello ea phekolo ea mocheso ka mor'a ho cheseha ka matla a ts'usumetso ea tšepe ea weld e fapana le mefuta e fapaneng ea tšepe. Phekolo ea mocheso ka mor'a weld hangata e sebelisa mocheso o le mong oa mocheso o phahameng kapa ho tloaeleha hammoho le mocheso o phahameng oa mocheso. Normalizing hammoho le mocheso o phahameng oa mocheso o futhumatsang mocheso o sebelisoa bakeng sa li-welds tsa khase. Lebaka ke hobane lithollo tsa li-welld tsa khase le libaka tse anngoeng ke mocheso li mahoashe 'me li hloka ho hloekisoa, kahoo ho sebelisoa kalafo e tloaelehileng. Leha ho le joalo, tloaelo e le 'ngoe e ke ke ea felisa khatello ea kelello e setseng, kahoo mocheso o phahameng oa mocheso o hlokahalang ho felisa khatello ea kelello. Mocheso o le mong oa mocheso o lekaneng o loketse feela bakeng sa ho tjheseletsa ha lijana tse kholo tse tloaelehileng tsa tšepe tse tlaase tsa carbon tse bokelletsoeng setšeng, 'me sepheo sa eona ke ho finyella ho felisa khatello ea kelello e setseng le dehydrogenation. Maemong a mangata, ho sebelisoa mocheso o le mong oa mocheso o phahameng. Ho futhumatsa le ho pholile ha phekolo ea mocheso ha hoa lokela ho potlaka haholo, 'me marako a ka hare le a ka ntle a lokela ho tšoana.

02 Mekhoa ea phekolo ea mocheso e sebelisoang lijaneng tsa khatello

Ho na le mefuta e 'meli ea mekhoa ea phekolo ea mocheso e sebelisoang likepeng tsa khatello: e' ngoe ke phekolo ea mocheso ho ntlafatsa thepa ea mechine; e 'ngoe ke post-weld heat treatment (PWHT). Ka kutloisiso e pharaletseng, phekolo ea mocheso oa post-weld ke phekolo ea mocheso ea sebaka sa welding kapa likarolo tse nang le welded ka mor'a hore workpiece e kenngoe. Likahare tse tobileng li kenyelletsa ho fokotsa khatello ea kelello, ho tlatsa ka botlalo, tharollo, ho tloaeleha, ho tloaeleha le ho halefisa, ho fokotsa mocheso, mocheso o tlaase oa khatello ea maikutlo, phekolo ea mocheso oa pula, joalo-joalo. ke hore, e le hore ho ntlafatsa tshebetso ya sebakeng tjheseletsa le ho felisa liphello tse kotsi tse kang tjheseletsa masala khatello ea kelello, sebaka tjheseletsa le likarolo tse amanang ka tsela e tšoanang 'me ka ho feletseng halefile tlas'a tšepe mohato phetoho mocheso ntlha 2, ebe ka tsela e tšoanang cooled. Maemong a mangata, phekolo ea mocheso oa post-weld eo ho buisanoang ka eona ke ha e le hantle ka mor'a-weld khatello ea kelello ea liphallelo mocheso.

03Morero oa kalafo ea mocheso ka mor'a weld

1. Phomola tjheseletsa mesaletsa khatello ea kelello.
2. Tsitsisa sebopeho le boholo ba sebopeho le ho fokotsa ho khopama.
3. Ntlafatsa ts'ebetso ea lisebelisoa tsa motsoali le manonyeletso a cheselitsoeng, ho kenyelletsa: a. Ntlafatsa polasetiki ea tšepe ea weld. b. Fokotsa ho thatafala ha sebaka se amehileng ke mocheso. c. Ntlafatsa ho tiea ha fracture. d. Ntlafatsa matla a mokhathala. e. Khutlisa kapa u ntlafatse matla a chai a fokotsehileng nakong ea ho theha serame.
4. Ntlafatsa bokhoni ba ho hanela khatello ea maikutlo.
5. Ho tsoela pele ho lokolla likhase tse kotsi ka tšepe ea weld, haholo-holo hydrogen, ho thibela ho hlaha ha mapetsong a liehang.

04Kahlolo ea bohlokoa ba PWHT

Ho sa tsotellehe hore na sekepe sa khatello se hloka phekolo ea mocheso ka mor'a weld e lokela ho hlalosoa ka ho hlaka moralong, 'me litlhaloso tsa moralo oa sekepe sa khatello ea hona joale li na le litlhoko tsa sena.
Bakeng sa likepe tsa khatello tse cheselitsoeng, ho na le khatello e kholo ea masala sebakeng sa welding, le litlamorao tse mpe tsa khatello e setseng. Feela tlas'a maemo a itseng a bonahala. Ha khatello ea kelello e setseng e kopana le hydrogen ka har'a weld, e tla khothalletsa ho thatafala ha sebaka se anngoeng ke mocheso, e leng se etsang hore ho be le mapetsong a batang le mapetsong a liehang.
Ha khatello e tsitsitseng e setseng ho weld kapa khatello e matla nakong ea ts'ebetso ea mojaro e kopantsoe le phello e senyang ea bohareng, e ka baka corrosion ea crack, e bitsoang "stress corrosion". Khatello ea masala ea welding le ho thatafala ha thepa ea motheo e bakoang ke ho cheselletsa ke lintlha tsa bohlokoa molokong oa mapetsong a khatello ea maikutlo.

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Liphello tsa lipatlisiso li bontša hore phello e ka sehloohong ea ho senyeha le khatello e setseng holim'a thepa ea tšepe ke ho fetola tšepe ho tloha ho corrosion e ts'oanang ho ea ho ea sebakeng seo, ke hore, ho pota-pota kapa ho pota-pota. Ha e le hantle, ho phunyeha ha tšepe ea tšepe le intergranular corrosion ka bobeli li etsahala mecheng ea litaba e nang le litšobotsi tse itseng tsa tšepe. Boteng ba khatello ea maikutlo e setseng, mofuta oa tšenyo ea kutu e ka fetoha ho latela sebopeho, mahloriso le mocheso oa sebaka se senyang, hammoho le phapang ea sebopeho, mokhatlo, boemo ba bokaholimo, boemo ba khatello ea maikutlo, joalo-joalo. le sebaka sa weld.

Ho sa tsotellehe hore na likepe tsa khatello tse cheselitsoeng li hloka phekolo ea mocheso ka mor'a weld e lokela ho khethoa ka ho nahanela ka botlalo morero, boholo (haholo-holo botenya ba lerako), ts'ebetso ea thepa e sebelisoang, le maemo a sebetsang a sekepe. Kalafo ea mocheso oa post-weld e lokela ho nahanoa maemong afe kapa afe a latelang:

1. Maemo a thata a ts'ebetso, joalo ka likepe tse nang le marako a teteaneng tse nang le kotsi ea ho robeha ha brittle mocheso o tlase, le likepe tse jereng meroalo e meholo le meroalo e fapanyetsanang.

2. Lijana tsa khatello tse cheselitsoeng tse nang le botenya bo fetang moeli o itseng. Ho kenyelletsa li-boilers, likepe tsa khatello ea petrochemical, joalo-joalo, tse nang le melao le litlhaloso tse khethehileng.

3. Lijana tsa khatello tse nang le botsitso bo phahameng ba dimensional.

4. Lijana tse entsoeng ka tšepe tse nang le tšekamelo e phahameng ea ho thatafatsa.

5. Lijana tsa khatello tse nang le kotsi ea ho senyeha ha khatello ea maikutlo.

6. Lijana tse ling tsa khatello tse boletsoeng ke melao e khethehileng, litlhaloso le litšoantšo.

Lijaneng tsa khatello tse entsoeng ka tšepe, khatello e setseng e fihlang sebakeng sa tlhahiso e thehoa sebakeng se haufi le weld. Moloko oa khatello ena e amana le phetoho ea sebopeho se kopantsoeng le austenite. Bafuputsi ba bangata ba bontša hore e le ho felisa khatello ea kelello e setseng ka mor'a ho cheselletsa, ho futhumatsa ka likhato tse 650 ho ka ba le phello e ntle holim'a likepe tsa khatello tse entsoeng ka tšepe.

Ka nako e ts'oanang, ho lumeloa hore haeba phekolo e nepahetseng ea mocheso e sa etsoe ka mor'a ho tjheseletsa, ho ke ke ha fumanoa manonyeletso a thibileng a manganga.

Ka kakaretso ho lumeloa hore kalafo ea mocheso oa khatello ea maikutlo ke ts'ebetso eo sesebelisoa se cheselitsoeng se futhumatsang ho likhato tse 500-650 ebe se pholile butle. Ho fokotseha ha khatello ea kelello ho bakoa ke ho theoha ha mocheso o phahameng, o qalang ho tloha ho likhato tse 450 ka carbon steel le likhato tse 550 ka tšepe e nang le molybdenum.

Ha mocheso o phahame, ho bonolo ho felisa khatello ea kelello. Leha ho le joalo, hang ha mocheso oa pele oa mocheso oa tšepe o feta, matla a tšepe a tla fokotseha. Ka hona, phekolo ea mocheso bakeng sa ho imolla khatello ea kelello e tlameha ho tseba likarolo tse peli tsa mocheso le nako, 'me ha ho letho le hlokahalang.

Leha ho le joalo, khatellong ea ka hare ea weldment, khatello ea maikutlo le khatello ea khatello ea kelello e lula e tsamaea le khatello ea kelello le deformation ea elastic ka nako e le 'ngoe. Ha mocheso oa tšepe o phahama, matla a tlhahiso a fokotseha, 'me deformation ea pele ea elastic e tla fetoha deformation ea polasetiki, e leng ho phomola ha khatello ea kelello.

Ha mocheso o futhumatsang o phahame, khatello ea ka hare e phethehile haholoanyane. Leha ho le joalo, ha mocheso o le holimo haholo, bokaholimo ba tšepe bo tla ba oxidized haholo. Ho phaella moo, bakeng sa mocheso oa PWHT oa tšepe e tingoeng le e halefileng, molao-motheo ha oa lokela ho feta mocheso oa pele oa mocheso oa tšepe, oo ka kakaretso o leng ka tlase ho likhato tse 30 ho feta mocheso oa pele oa mocheso oa tšepe, ho seng joalo thepa e tla lahleheloa ke ho tima. phello e halefisang, 'me matla le fracture toughness tla fokotseha. Ntlha ena e lokela ho fuoa tlhokomelo e khethehileng ho basebetsi ba phekolo ea mocheso.

Ho phahama ha mocheso oa mocheso oa post-weld bakeng sa ho felisa khatello ea kelello ea ka hare, ho na le tekanyo e kholo ea ho nolofatsa tšepe. Hangata, khatello ea kelello e ka hare e ka felisoa ka ho futhumatsa mocheso oa recrystallization oa tšepe. Mocheso oa recrystallization o amana haufi-ufi le mocheso o qhibilihang. Ka kakaretso, mocheso oa recrystallization K=0.4X mocheso o qhibilihang (K). Ha mocheso oa mocheso oa mocheso o haufi le mocheso oa recrystallization, o atleha haholoanyane ho felisa khatello ea kelello e setseng.

04 Ho nahanoa ka phello e akaretsang ea PWHT

Kalafo ea mocheso ka mor'a weld ha e na molemo ka ho feletseng. Ka kakaretso, kalafo ea mocheso oa post-weld e thusa ho imolla khatello ea maikutlo e setseng mme e etsoa feela ha ho na le litlhokahalo tse tiileng bakeng sa kutu ea khatello ea maikutlo. Leha ho le joalo, teko ea matla a tšusumetso ea mehlala e bontšitse hore phekolo ea mocheso ka mor'a weld e ne e sa thuse ho ntlafatsa ho tiea ha tšepe e kentsoeng le sebaka se amehileng ke mocheso, 'me ka linako tse ling ho phunyeha ha intergranular ho ka etsahala ka har'a mefuta e mengata ea lijo-thollo tsa mocheso o amehileng. sebaka.

Ho feta moo, PWHT e itšetlehile ka phokotso ea matla a lintho tse bonahalang mochesong o phahameng ho felisa khatello ea maikutlo. Ka hona, nakong ea PWHT, mohaho o ka lahleheloa ke ho tiea. Bakeng sa meaho e amohelang PWHT ka kakaretso kapa e sa fellang, matla a ts'ehetso ea weldment ka mocheso o phahameng o tlameha ho nahanoa pele ho kalafo ea mocheso.

Ka hona, ha ho nahanoa hore na ho etsoa phekolo ea mocheso ka mor'a weld, melemo le melemo ea phekolo ea mocheso e lokela ho bapisa ka ho feletseng. Ho latela pono ea ts'ebetso ea sebopeho, ho na le lehlakore le ntlafatsang ts'ebetso le lehlakore le fokotsang ts'ebetso. Kahlolo e utloahalang e lokela ho etsoa e thehiloeng mosebetsing oa motheo oa ho hlahloba ka botlalo likarolo tseo ka bobeli.