1. Bayanin ƙarfe na cryogenic karfe
1) Abubuwan da ake buƙata na fasaha don ƙananan ƙananan ƙarfe suna gabaɗaya: isasshen ƙarfi da isasshen ƙarfi a cikin yanayin yanayin zafi, aikin walda mai kyau, aikin sarrafawa da juriya na lalata, da sauransu. don hana abin da ya faru da fadada karaya a ƙananan zafin jiki shine mafi mahimmancin mahimmanci.Don haka, ƙasashe yawanci suna ƙayyade ƙimar taurin tasiri a mafi ƙarancin zafin jiki.
2) Daga cikin abubuwan da ke cikin karfen da ba su da zafi, an yi imani da cewa abubuwa irin su carbon, silicon, phosphorus, sulfur, nitrogen suna lalata taurin zafin jiki, kuma sinadarin phosphorus shi ne mafi illa, don haka ya kamata a rika rage yawan zafin jiki da wuri. yi a lokacin narkawa.Abubuwa irin su manganese da nickel na iya inganta ƙarancin zafin jiki.Ga kowane karuwar kashi 1% na abun ciki na nickel, za a iya rage tsananin zafin canjin yanayi da kusan 20°C.
3) Tsarin maganin zafi yana da tasiri mai mahimmanci akan tsarin metallographic da girman hatsi na ƙananan zafin jiki, wanda kuma yana rinjayar ƙananan zafin jiki na karfe.Bayan quenching da tempering jiyya, da ƙananan zafin jiki taurin yana a fili inganta.
4) Dangane da hanyoyin samar da zafi daban-daban, ƙananan zafin jiki na ƙarfe za a iya raba zuwa simintin ƙarfe da birgima.Dangane da bambanci na abun da ke ciki da tsarin metallographic, ƙananan zafin jiki na karfe za a iya raba zuwa: ƙananan gami karfe, 6% nickel karfe, 9% nickel karfe, chromium-manganese ko chromium-manganese-nickel austenitic karfe da chromium-nickel austenitic bakin karfe. jira.Ana amfani da ƙananan ƙarfe mai ƙarancin ƙarfi a cikin kewayon zafin jiki na kusan -100 ° C don kera na'urorin sanyaya, kayan sufuri, ɗakunan ajiya na vinyl da kayan aikin petrochemical.A cikin Amurka, Ingila, Japan da sauran ƙasashe, 9% nickel karfe ana amfani dashi sosai a cikin ƙananan zafin jiki a 196 ° C, kamar tankunan ajiya don ajiya da jigilar gas mai ruwa da methane, kayan aiki don adana oxygen na ruwa. , da kuma kera ruwa oxygen da ruwa nitrogen.Austenitic bakin karfe abu ne mai kyau mai ƙarancin zafin jiki.Yana da ƙaƙƙarfan ƙarancin zafin jiki, kyakkyawan aikin walda, da ƙarancin ƙarancin zafin jiki.Ana amfani da shi sosai a cikin ƙananan wurare masu zafi, kamar motocin jigilar kayayyaki da tankunan ajiya don hydrogen ruwa da oxygen na ruwa.Duk da haka, saboda ya ƙunshi ƙarin chromium da nickel, ya fi tsada.
2. Overview na low zafin jiki karfe waldi yi
Lokacin zabar hanyar aikin walda da yanayin ginin ƙarfe mai ƙarancin zafin jiki, abin da ya fi mayar da hankali kan matsalar shine a kan abubuwa biyu masu zuwa: hana lalacewar ƙarancin zafin jiki na haɗin gwiwa da hana faruwar fashewar walda.
1) sarrafa bevel
The tsagi nau'i na low-zazzabi karfe welded gidajen abinci ba daban-daban bisa manufa da na talakawa carbon karfe, low gami karfe ko bakin karfe, kuma za a iya bi kamar yadda aka saba.Amma ga 9Ni Gang, kusurwar buɗewa na tsagi ya fi dacewa ba ƙasa da digiri 70 ba, kuma ɓacin rai zai fi dacewa ba ƙasa da 3mm ba.
Za a iya yanke duk ƙananan ƙananan ƙarfe na ƙarfe tare da fitilar oxyacetylene.Yana da kawai cewa sabon gudun ne dan kadan a hankali a lokacin da gas yankan 9Ni karfe fiye da lokacin da gas yankan talakawa carbon tsarin karfe.Idan kauri daga cikin karfe ya wuce 100mm, za a iya preheated gefen yankan zuwa 150-200 ° C kafin yanke gas, amma bai wuce 200 ° C ba.
Yankewar iskar gas ba shi da wata illa ga wuraren da zafin walda ya shafa.Duk da haka, saboda kaddarorin da ke da ƙarfi na ƙarfe mai ɗauke da nickel, saman da aka yanke zai taurare.Domin tabbatar da kyakkyawan aikin haɗin gwiwa na welded, yana da kyau a yi amfani da dabaran niƙa don niƙa saman da aka yanke mai tsabta kafin waldawa.
Ana iya amfani da gogaggen ƙwanƙwasa idan ana so a cire ƙurar walda ko ƙarfe mai tushe yayin aikin walda.Duk da haka, ya kamata a yi yashi mai tsabta kafin a sake yin amfani da saman darajar.
Bai kamata a yi amfani da gogaggun wuta na Oxyacetylene ba saboda haɗarin zafi da ƙarfe.
2) Zaɓin hanyar walda
Hannun walda na yau da kullun da ake samu don ƙarancin zafin ƙarfe sun haɗa da waldawar baka, walƙiyar baka mai nutsewa, da narkakkar wutar lantarki argon arc waldi.
Arc walda ita ce hanyar walda wacce aka fi amfani da ita don ƙarancin zafin ƙarfe, kuma ana iya walda shi a wurare daban-daban na walda.Shigar da zafin walda yana kusan 18-30KJ/cm.Idan aka yi amfani da na'urar lantarki mai ƙarancin hydrogen, za'a iya samun haɗin haɗin welded mai gamsarwa gaba ɗaya.Ba wai kawai kaddarorin injiniyoyi suna da kyau ba, amma ƙimar daraja kuma tana da kyau sosai.Bugu da ƙari, na'urar waldawa na arc yana da sauƙi kuma mai arha, kuma zuba jari na kayan aiki yana da ƙananan, kuma matsayi da shugabanci ba su shafi shi ba.abũbuwan amfãni kamar gazawa.
Shigar da zafi na waldawar baka mai ƙarancin zafin jiki kusan 10-22KJ/cm.Saboda kayan aiki mai sauƙi, babban aikin walda da aiki mai dacewa, ana amfani dashi ko'ina.Duk da haka, saboda tasirin zafi mai zafi na juyi, za a rage yawan kwantar da hankali, don haka akwai mafi girman hali don haifar da fashewar zafi.Bugu da ƙari, ƙazanta da Si na iya sau da yawa shiga ƙarfen walda daga juyi, wanda zai ƙara ƙarfafa wannan hali.Don haka, Lokacin amfani da waldawar baka mai nutsewa, kula da zaɓin waya na walda da juyi kuma yi aiki a hankali.
Haɗin da aka haɗa ta CO2 gas mai kariya waldi yana da ƙarancin ƙarfi, don haka ba a amfani da su a cikin ƙaramin zafin ƙarfe na walda.
Tungsten argon arc waldi (TIG waldi) yawanci ana yin shi da hannu, kuma shigar da zafin walda ɗin sa yana iyakance zuwa 9-15KJ/cm.Saboda haka, ko da yake welded gidajen abinci suna da cikakken gamsarwa Properties, ba su da gaba daya m lokacin da karfe kauri ya wuce 12mm.
MIG walda ita ce mafi ko'ina amfani da atomatik ko Semi-atomatik hanya waldi a cikin ƙananan zafin jiki waldi.Its waldi zafi shigar ne 23-40KJ/cm.Dangane da hanyar canja wuri, ana iya kasu kashi uku: Tsarin canja wuri na gajere), shigarwar zafi) da kuma shigarwar zafi).Canje-canje na gajeren lokaci MIG walda yana da matsalar rashin isashen shiga, kuma lahani mara kyau na iya faruwa.Matsaloli iri ɗaya suna wanzu tare da wasu motsin MIG, amma zuwa wani mataki daban.Domin sanya baka ya fi mai da hankali don cimma gamsasshen kutsawa, kashi da yawa zuwa dubun na CO2 ko O2 ana iya kutsawa cikin tsantsar argon a matsayin iskar kariya.Za a ƙayyade kaso masu dacewa ta gwaji don takamaiman ƙarfen da ake waldawa.
3) Zaɓin kayan walda
Kayan walda (ciki har da sandar walda, wayar walda da juyi, da dai sauransu) yakamata a dogara ne akan hanyar walda da ake amfani da su.Siffar haɗin gwiwa da siffar tsagi da sauran halaye masu mahimmanci don zaɓar.Don ƙananan zafin jiki, abu mafi mahimmanci a kula da shi shine sanya ƙarfen walda ya sami ƙarancin zafin jiki wanda ya isa ya dace da ƙarfe na tushe, kuma rage abun ciki na hydrogen mai yaduwa a cikinsa.
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(1) Aluminum deoxidized karfe
Aluminum deoxidized karfe ne karfe sa cewa yana da matukar kula da tasiri na sanyaya kudi bayan waldi.Yawancin na'urorin lantarki da ake amfani da su a cikin waldawar baka na aluminum deoxidized karfe sune Si-Mn low-hydrogen electrodes ko 1.5% Ni da 2.0% Ni electrodes.
Domin rage shigar da zafi walda, aluminum deoxidized karfe gabaɗaya kawai rungumi multi-Layer waldi tare da bakin ciki electrodes na ≤¢3 ~ 3.2mm, sabõda haka, na biyu zafi sake zagayowar na babba Layer na weld za a iya amfani da su tace da hatsi.
Tasirin ƙarfin ƙarfe na walda wanda aka yi masa walda tare da Si-Mn jerin lantarki zai ragu sosai a 50 ℃ tare da haɓakar shigarwar zafi.Misali, lokacin da shigarwar zafi ya karu daga 18KJ/cm zuwa 30KJ/cm, taurin zai rasa fiye da 60%.1.5%Ni jerin da 2.5%Ni jerin walda lantarki ba su da mahimmanci ga wannan, don haka yana da kyau a zaɓi irin wannan nau'in lantarki don waldawa.
Waldawar baka hanya ce ta walƙiya ta atomatik da aka saba amfani da ita don ƙarancin ƙarfe na aluminum.Wayar walda da aka yi amfani da ita a cikin waldawar arc da ta nutse ta fi dacewa da nau'in da ke ɗauke da 1.5 ~ 3.5% nickel da 0.5 ~ 1.0% molybdenum.
Bisa ga wallafe-wallafen, tare da 2.5% Ni - 0.8% Cr - 0.5% Mo ko 2% Ni waya walda, wanda ya dace da daidaitaccen juzu'i, matsakaicin ƙarfin ƙarfin Charpy na ƙarfe na weld a -55 ° C zai iya kaiwa 56-70J (5.7). 7.1Kgf.m).Ko da lokacin da aka yi amfani da 0.5% Mo waldi waya da manganese alloy asali juyi, muddin ana sarrafa shigarwar zafi ƙasa da 26KJ/cm, ana iya samar da ƙarfe mai walda tare da ν∑-55=55J (5.6Kgf.m).
Lokacin zabar juzu'i, ya kamata a biya hankali ga daidaitawar Si da Mn a cikin ƙarfen walda.Tabbacin gwaji.Abubuwan da ke cikin Si da Mn daban-daban a cikin ƙarfen walda za su canza ƙimar taurin Charpy sosai.Abubuwan da ke cikin Si da Mn tare da mafi kyawun ƙimar tauri sune 0.1 ~ 0.2% Si da 0.7 ~ 1.1% Mn.Lokacin zabar waya mai walda kuma Yi la'akari da wannan lokacin soldering.
Tungsten argon baka waldi da karfe argon baka walda ba a yi amfani da su a cikin aluminum deoxidized karfe.Hakanan ana iya amfani da wayoyi na walda na sama don waldawar baka mai nutsewa don waldawar argon.
(2) 2.5Ni karfe da 3.5Ni
Waldawar baka mai nutsewa ko waldawar MIG na karfe 2.5Ni da karfe 3.5Ni gabaɗaya ana iya haɗa su da waya iri ɗaya da kayan tushe.Amma kamar yadda dabarar Wilkinson (5) ta nuna, Mn wani nau'in hanawa ne mai zafi don ƙarancin ƙarancin nickel.Ajiye abun ciki na manganese a cikin karfen walda a kusan 1.2% yana da matukar fa'ida don hana fashewar zafi kamar tsagewar ramin baka.Ya kamata a yi la'akari da wannan lokacin zabar haɗin wayar walda da juyi.
3.5Ni karfe oyan da za a tempered da embrittled, don haka bayan post-weld magani magani (misali, 620 ° C × 1 hour, sa'an nan tanderu sanyaya) don kawar da saura danniya, ν∑-100 zai sauke sharply daga 3.8 Kgf.m to. 2.1Kgf.m ba zai iya cika buƙatun ba.Karfe na walda wanda aka kafa ta hanyar waldawa tare da 4.5% Ni-0.2% Mo jerin walda waya yana da ƙaramin hali na fushi.Yin amfani da wannan wayar walda zai iya guje wa matsalolin da ke sama.
(3) 9Ni karfe
9Ni karfe yawanci zafi ana bi da su ta hanyar kashewa da zafin rai ko sau biyu na daidaitawa da zafin jiki don haɓaka ƙarancin zafinsa.Amma karfen walda na wannan karfe ba za a iya kula da zafi kamar yadda yake a sama ba.Don haka, yana da wahala a sami ƙarfen walda tare da taurin ƙarancin zafin jiki kwatankwacin na ƙarfen tushe idan an yi amfani da kayan aikin walda na ƙarfe.A halin yanzu, ana amfani da kayan walda masu girma na nickel.Welds da aka ajiye ta irin waɗannan kayan walda za su kasance gaba ɗaya austenitic.Ko da yake yana da lahani na ƙarancin ƙarfi fiye da kayan tushe na ƙarfe na 9Ni da farashi masu tsada sosai, karyewar karyewar ba ta zama babbar matsala gare shi ba.
Daga abin da ke sama, ana iya sanin cewa saboda ƙarfen walda gaba ɗaya austenitic ne, ƙarancin zafin ƙarfin ƙarfen walda da ake amfani da shi don waldawa da na'urorin lantarki da wayoyi gabaɗaya ya yi daidai da na ƙarfen tushe, amma ƙarfin ƙarfi da ma'aunin ƙima. m fiye da tushe karfe.Ƙarfe mai ɗauke da nickel yana da ƙarfi, don haka yawancin lantarki da wayoyi suna kula da iyakance abubuwan da ke cikin carbon don cimma kyakkyawan walƙiya.
Mo yana da mahimmancin ƙarfafawa a cikin kayan walda, yayin da Nb, Ta, Ti da W sune mahimman abubuwan ƙarfafawa, waɗanda aka ba da cikakkiyar kulawa a zaɓin kayan walda.
Idan aka yi amfani da wayar walda iri ɗaya wajen yin walda, ƙarfi da ƙaƙƙarfan ƙarfen walda na baƙar walda sun fi na MIG walda, wanda zai iya faruwa ta hanyar raguwar yanayin sanyaya walda da yuwuwar kutsawa na ƙazanta ko Sisi. daga magudanar ruwa.
3. A333-GR6 low zafin jiki karfe bututu waldi
1) Weldability bincike na A333-GR6 karfe
A333-GR6 karfe na da low-zazzabi karfe, mafi ƙarancin sabis zafin jiki ne -70 ℃, kuma yawanci ana kawota a al'ada ko al'ada da tempered jihar.A333-GR6 karfe yana da low carbon abun ciki, don haka hardening hali da sanyi fata hali ne in mun gwada da kananan, da abu yana da kyau tauri da kuma plasticity, shi ne kullum ba sauki don samar da hardening da fasa lahani, kuma yana da kyau weldability.ER80S-Ni1 argon baka walda waya za a iya amfani da W707Ni electrode, yi amfani da argon-lantarki hadin gwiwa waldi, ko amfani da ER80S-Ni1 argon baka waldi waya, da kuma amfani da cikakken argon baka waldi don tabbatar da kyau taurin welded gidajen abinci.Alamar argon baka walda waya da lantarki kuma za su iya zaɓar samfuran tare da aikin iri ɗaya, amma ana iya amfani da su kawai tare da izinin mai shi.
2) Tsarin walda
Don cikakkun hanyoyin aikin walda, da fatan za a koma zuwa littafin koyarwa tsarin walda ko WPS.A lokacin waldi, I-type butt haɗin gwiwa da cikakken argon baka waldi ana karɓa don bututu da diamita kasa da 76.2 mm;don bututu tare da diamita fiye da 76.2 mm, ana yin ramukan V-dimbin yawa, kuma ana amfani da hanyar haɗakarwar argon-lantarki tare da priming argon da ciko mai yawa ko Hanyar cikakken walƙiya argon arc.Hanya ta musamman ita ce zabar hanyar walda daidai gwargwadon bambancin diamita na bututu da kaurin bangon bututu a cikin WPS wanda mai shi ya amince da shi.
3) Tsarin maganin zafi
(1) Preheating kafin walda
Lokacin da yanayin zafi ya kasance ƙasa da 5 ° C, welding yana buƙatar preheated, kuma zafin zafin jiki shine 100-150 ° C;kewayon preheating shine 100 mm a bangarorin biyu na weld;ana dumama shi da harshen wuta na oxyacetylene ( harshen tsaka tsaki), kuma ana auna zafin jiki Alƙalami yana auna zafin jiki a nesa na 50-100 mm daga tsakiyar walda, kuma ana rarraba wuraren auna zafin jiki daidai gwargwado don sarrafa zafin jiki mafi kyau. .
(2) Maganin zafi bayan walda
Domin inganta ƙaƙƙarfan ƙarfe mai ƙarancin zafin jiki, kayan da ake amfani da su gabaɗaya an kashe su kuma an huce su.Maganin zafi mara kyau bayan walda sau da yawa yana lalata aikin ƙarancin zafinsa, wanda yakamata a ba da kulawa sosai.Sabili da haka, sai dai ga yanayin babban kauri na walda ko yanayin ƙuntatawa mai tsanani, ba a yin maganin zafi bayan waldawa yawanci don ƙananan zafin jiki.Misali, walda sabbin bututun LPG a cikin CSPC baya buƙatar maganin zafi bayan walda.Idan ana buƙatar jiyya mai zafi bayan walda da gaske a wasu ayyukan, ƙimar dumama, lokacin zafin jiki akai-akai da ƙimar sanyaya na jiyya bayan waldi dole ne ya kasance daidai da ƙa'idodi masu zuwa:
Lokacin da zafin jiki ya tashi sama da 400 ℃, ƙimar dumama kada ta wuce 205 × 25 / δ ℃ / h, kuma kada ya wuce 330 ℃ / h. Lokacin zafin jiki akai-akai yakamata ya zama sa'a 1 a cikin kauri na bango na 25 mm, kuma ba ƙasa da mintuna 15 ba.A lokacin yawan zafin jiki na yau da kullun, bambancin zafin jiki tsakanin mafi girma da mafi ƙarancin zafin jiki ya kamata ya zama ƙasa da 65 ℃.
Bayan yawan zafin jiki na yau da kullun, ƙimar sanyaya kada ya zama mafi girma 65 × 25/δ ℃/h, kuma kada ya zama sama da 260 ℃/h.Ana ba da izinin sanyaya yanayi ƙasa da 400 ℃.TS-1 nau'in kayan aikin kula da zafi da kwamfuta ke sarrafawa.
4) Hattara
(1) Tsananin preheat bisa ga ka'idoji, kuma sarrafa zafin jiki na interlayer, kuma ana sarrafa zafin jiki a 100-200 ℃.Kowane kabu na walda za a yi walda a lokaci ɗaya, kuma idan ya katse, za a ɗauki matakan sanyaya a hankali.
(2) An hana saman walda da ƙwarya da ƙwarya.Ya kamata a cika ramin baka kuma a niƙa lahanin da injin niƙa idan an rufe baka.Ya kamata a yi tagulla tsakanin yadudduka na walda mai yawa.
(3) Tsananin sarrafa makamashin layi, ɗaukar ƙaramin halin yanzu, ƙarancin wutar lantarki, da walƙiya mai sauri.Tsawon walda na kowane lantarki W707Ni tare da diamita na 3.2 mm dole ne ya fi 8 cm girma.
(4) Yanayin aiki na gajeriyar baka kuma babu lilo dole ne a ɗauka.
(5) Dole ne a karɓi cikakken tsarin shigar ciki, kuma dole ne a aiwatar da shi daidai da buƙatun ƙayyadaddun tsarin walda da katin aikin walda.
(6) Ƙarfafawa na weld shine 0 ~ 2mm, kuma nisa na kowane gefen weld shine ≤ 2mm.
(7) Za'a iya yin gwajin mara lalacewa aƙalla sa'o'i 24 bayan binciken gani na weld ya cancanci.Bututun butt welds za su kasance ƙarƙashin JB 4730-94.
(8) "Tsarin Matsi: Gwajin da ba mai lalacewa ba na Matsalolin Ruwa" misali, Class II ya cancanta.
(9) Gyaran weld ya kamata a yi kafin maganin zafi bayan walda.Idan gyara ya zama dole bayan maganin zafi, ya kamata a sake ɗora walda bayan gyarawa.
(10) Idan ma'auni na geometric na farfajiyar walda ya wuce misali, an yarda da nika, kuma kauri bayan niƙa ba zai zama ƙasa da abin da ake bukata ba.
(11) Don rashin lahani na walda na gabaɗaya, ana ba da izinin mafi girman gyare-gyare biyu.Idan gyare-gyaren biyu har yanzu ba su cancanta ba, dole ne a yanke walda a sake sake walda bisa ga cikakken aikin walda.
Lokacin aikawa: Juni-21-2023
