Lura cewa ba duk maganin zafi bayan walda ke da amfani ba

01 Zaɓin hanyar maganin zafi

Tasirin jiyya na zafi bayan walda akan ƙarfin juzu'i da ƙayyadaddun ƙaƙƙarfan ƙarfe yana da alaƙa da zafin jiki da riƙe lokacin jiyya mai zafi. Tasirin maganin zafi bayan walda akan tasirin taurin ƙarfe na walda ya bambanta da nau'ikan ƙarfe daban-daban. Maganin zafi bayan walda gabaɗaya yana amfani da zafin zafin jiki guda ɗaya ko daidaitawa tare da yanayin zafi mai zafi. Normalizing da high-zazzabi yanayin zafi magani ana amfani da gas walda walda. Wannan shi ne saboda hatsi na walda gas da kuma yankunan da zafi ya shafa suna da yawa kuma suna buƙatar tsaftacewa, don haka ana amfani da magani na yau da kullum. Duk da haka, daidaitawa guda ɗaya ba zai iya kawar da damuwa na saura ba, don haka ana buƙatar zafi mai zafi don kawar da damuwa. Single matsakaici-zazzabi tempering ne kawai dace da taron waldi na manyan talakawa low-carbon karfe kwantena harhada a kan site, da kuma manufar shi ne a cimma partially kawar da saura danniya da dehydrogenation. A mafi yawan lokuta, ana amfani da zafi mai zafi guda ɗaya. Dumama da sanyaya maganin zafi bai kamata ya zama da sauri ba, kuma bangon ciki da na waje ya kamata ya zama iri ɗaya.

02 Hanyoyin maganin zafi da aka yi amfani da su a cikin tasoshin matsa lamba

Akwai nau'i biyu na hanyoyin maganin zafi da ake amfani da su a cikin tasoshin matsa lamba: daya shine maganin zafi don inganta kayan aikin injiniya; ɗayan kuma shine maganin zafi bayan walda (PWHT). A cikin wani m ma'ana, post-weld zafi magani ne zafi magani na waldi yankin ko welded aka gyara bayan workpiece ne welded. Abubuwan da ke cikin ƙayyadaddun abubuwan da ke ciki sun haɗa da jin daɗin jin daɗin damuwa, cikewar ɓarna, bayani, daidaitawa, daidaitawa da haɓakawa, yanayin zafi, ƙarancin zafin jiki na jin zafi, hazo zafi magani, da sauransu. wato domin inganta aikin wurin walda da kuma kawar da illolin da ke haifar da illa kamar damuwa na walda, yankin walda da abubuwan da ke da alaƙa sun kasance iri ɗaya kuma suna da zafi sosai a ƙasa da yanayin canjin canjin ƙarfe na 2, sannan a sanyaya su daidai. A yawancin lokuta, maganin zafi na bayan walda da aka tattauna shine ainihin maganin jinyar damuwa bayan walda.

03 Manufar maganin zafi bayan walda

1. Shakata da damuwa saura walda.
2. Tabbatar da siffar da girman tsarin kuma rage murdiya.
3. Haɓaka aikin kayan iyaye da haɗaɗɗun welded, gami da: a. Inganta filastik na ƙarfe na walda. b. Rage taurin yankin da zafi ya shafa. c. Inganta taurin karaya. d. Inganta ƙarfin gajiya. e. Maidowa ko haɓaka ƙarfin amfanin gona da aka rage a lokacin sanyi.
4. Inganta ikon yin tsayayya da lalata damuwa.
5. Ci gaba da sakin iskar gas mai cutarwa a cikin ƙarfen walda, musamman hydrogen, don hana faruwar tsagewar tsagewa.

04 Hukuncin wajibcin PWHT

Ko jirgin ruwa yana buƙatar magani mai zafi bayan walda ya kamata a bayyana a sarari a cikin ƙirar, kuma ƙayyadaddun ƙirar jirgin ruwa na yanzu suna da buƙatu don wannan.
Domin welded matsa lamba tasoshin, akwai babban saura danniya a cikin walda yankin, da kuma illar da saura danniya. Sai kawai a ƙarƙashin wasu sharuɗɗa suna bayyana. Lokacin da ragowar damuwa ya haɗu tare da hydrogen a cikin walda, zai inganta taurin yankin da zafi ya shafa, wanda zai haifar da fashewar sanyi da jinkirta tsage.
Lokacin da matsananciyar damuwa da ta rage a cikin walda ko matsananciyar damuwa yayin aiki na kaya yana haɗuwa tare da lalatawar matsakaici, yana iya haifar da lalata, wanda ake kira lalata damuwa. Welding saura danniya da taurin tushe abu lalacewa ta hanyar waldi abubuwa ne masu muhimmanci a cikin ƙarni na damuwa lalata fasa.

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Sakamakon binciken ya nuna cewa babban tasirin nakasawa da ragowar damuwa akan kayan ƙarfe shine canza ƙarfe daga lalata iri ɗaya zuwa lalatawar gida, wato, zuwa lalatawar intergranular ko transgranular. Tabbas, lalatawar ƙarfe da lalatawar intergranular duka suna faruwa a cikin kafofin watsa labarai tare da wasu halaye na ƙarfe. A gaban danniya na saura, yanayin lalacewar lalacewa na iya canzawa dangane da abun da ke ciki, maida hankali da zafin jiki na matsakaici mai lalata, da kuma bambance-bambance a cikin abun da ke ciki, ƙungiya, yanayin ƙasa, yanayin damuwa, da dai sauransu na kayan tushe. da yankin weld.

Ko welded matsa lamba tasoshin bukatar post-weld magani zafi ya kamata a ƙayyade ta cikakken la'akari da manufar, size (musamman kauri bango), yi na kayan amfani, da kuma aiki yanayin jirgin ruwa. Ya kamata a yi la'akari da maganin zafi bayan walda a cikin kowane yanayi masu zuwa:

1. Yanayin aiki mai tsauri, kamar tasoshin da ke da kauri mai kauri tare da haɗarin karaya a ƙananan zafin jiki, da tasoshin da ke ɗauke da manyan lodi da sauran lodi.

2. Welded matsa lamba tasoshin tare da kauri wuce iyaka iyaka. Ciki har da tukunyar jirgi, tasoshin matsa lamba na petrochemical, da sauransu, waɗanda ke da ƙa'idodi na musamman da ƙayyadaddun bayanai.

3. Tasoshin matsin lamba tare da kwanciyar hankali mai girma.

4. Kwantena da aka yi da karfe tare da babban hali don taurara.

5. Tasoshin matsin lamba tare da haɗarin damuwa lalata lalata.

6. Sauran tasoshin matsa lamba da aka ƙayyade ta ƙa'idodi na musamman, ƙayyadaddun bayanai, da zane-zane.

A cikin tasoshin matsa lamba na welded karfe, raguwar damuwa da ke kaiwa wurin samun amfanin gona yana samuwa a yankin kusa da walda. Ƙirƙirar wannan damuwa yana da alaƙa da sauye-sauyen tsarin da aka haɗe da austenite. Yawancin masu bincike sun nuna cewa don kawar da damuwa na saura bayan waldi, zafin jiki a digiri 650 na iya yin tasiri mai kyau akan tasoshin matsa lamba na welded.

Haka kuma, an yi imanin cewa idan ba a yi maganin zafin da ya dace ba bayan walda, ba za a taɓa samun gurɓataccen walda ba.

An yi imani da cewa danniya taimako zafi magani ne mai tsari a cikin abin da welded workpiece ne mai tsanani zuwa 500-650 digiri sa'an nan a hankali sanyaya. Rage damuwa yana faruwa ne ta hanyar rarrafe a babban zafin jiki, wanda ke farawa daga digiri 450 a cikin ƙarfe na carbon da digiri 550 a cikin ƙarfe mai ɗauke da molybdenum.

Mafi girman zafin jiki, mafi sauƙi shine kawar da damuwa. Koyaya, da zarar ainihin zafin zafin karfen ya wuce, ƙarfin ƙarfen zai ragu. Don haka, maganin zafi don rage damuwa dole ne ya mallaki abubuwa biyu na zafin jiki da lokaci, kuma babu makawa.

Duk da haka, a cikin damuwa na ciki na walda, damuwa da damuwa da damuwa suna tare da kullun, kuma damuwa da nakasar nakasa suna wanzu a lokaci guda. Lokacin da zafin jiki na karfe ya tashi, ƙarfin yawan amfanin ƙasa yana raguwa, kuma ainihin nakasawa na roba zai zama nakasar filastik, wanda shine shakatawa na danniya.

Mafi girman yawan zafin jiki na dumama, mafi cikakken an kawar da damuwa na ciki. Duk da haka, lokacin da zafin jiki ya yi yawa, saman karfe zai zama oxidized mai tsanani. Bugu da ƙari, don zafin jiki na PWHT na quenched da ƙera karfe, ka'idar kada ta wuce ainihin zafin jiki na karfe, wanda yawanci kusan digiri 30 ne fiye da ainihin zafin jiki na karfe, in ba haka ba kayan zai rasa quenching kuma tempering sakamako, da kuma ƙarfi da karaya taurin za a rage. Wannan batu ya kamata a ba da kulawa ta musamman ga ma'aikatan maganin zafi.

Mafi girma da zafin zafin jiki na bayan-weld don kawar da damuwa na ciki, mafi girma digiri na laushi na karfe. Yawancin lokaci, ana iya kawar da damuwa na ciki ta hanyar dumama zuwa zazzabi na recrystallization na karfe. Zazzabi na recrystallization yana da alaƙa da yanayin zafi mai narkewa. Gabaɗaya, zazzabi recrystallization K=0.4X zafin narkewa (K). Mafi kusancin zafin zafin zafin zafi shine zuwa zazzabi recrystallization, mafi inganci shine kawar da damuwa.

04 La'akari da cikakken tasirin PWHT

Maganin zafi bayan walda ba shi da cikakkiyar fa'ida. Gabaɗaya magana, maganin zafi bayan walda yana da amfani don kawar da damuwa na saura kuma ana aiwatar da shi ne kawai idan akwai ƙaƙƙarfan buƙatu don lalata damuwa. Duk da haka, tasirin gwajin gwagwarmayar samfurori ya nuna cewa maganin zafi na bayan-weld bai dace ba don inganta ƙarfin ƙarfe da aka ajiye da kuma yankin da zafi ya shafa, kuma wani lokacin tsaka-tsakin tsaka-tsakin na iya faruwa a cikin ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar cuta. yankin.

Bugu da ƙari kuma, PWHT yana dogara ne akan rage ƙarfin abu a yanayin zafi mai zafi don kawar da damuwa. Saboda haka, a lokacin PWHT, tsarin zai iya rasa rashin ƙarfi. Don tsarin da suka ɗauki PWHT gabaɗaya ko ɓangarori, dole ne a yi la'akari da ƙarfin goyan bayan walda a yanayin zafi mai zafi kafin maganin zafi.

Sabili da haka, lokacin la'akari da ko yin maganin zafi bayan walda, amfani da rashin amfani na maganin zafi ya kamata a kwatanta shi sosai. Daga mahangar aikin tsarin, akwai wani gefen da ke inganta aikin da kuma gefen da ke rage yawan aiki. Ya kamata a yi hukunci mai ma'ana bisa tushen aikin na cikakken la'akari da bangarorin biyu.