Dabaru na Walda na Nickel Metal don Masana'antar Man Fetur
Masana'antar mai tana aiki a ƙarƙashin yanayi mai tsauri: yanayin zafi mai yawa, matsin lamba mai yawa, da kuma fallasa ga kafofin watsa labarai masu lalata kamar chloride, sulfur, H₂S, CO₂, da mahaɗan acidic daban-daban. A cikin waɗannan muhalli, zaɓin abu shine abin da ke tantance ingancin kayan aikin sarrafawa. Ana amfani da ƙarfe masu tushen nickel (nickel da ƙarfe) sosai saboda juriyarsu ta tsatsa, kwanciyar hankali mai zafi, da ikon tsayayya da tsatsa mai ƙarfi. Duk da haka, waɗannan fa'idodi za a iya cimma su ne kawai idan an gudanar da aikin walda ta amfani da dabarar da ta dace, domin walda na iya canza tsarin kayan, haifar da tsatsa mai zafi, porosity, ko rage juriyar tsatsa a yankin walda.
1. Matsayin gami da nickel a cikin sinadarai masu amfani da man fetur
Ana amfani da ƙarfen nickel kamar Nickel 200/201, Monel (Ni-Cu), Inconel (Ni-Cr-Fe), Incoloy, da Hastelloy (Ni-Mo-Cr) a cikin masu musayar zafi, ginshiƙan distillation, reactors, bututun sarrafawa, kayan aikin desulfurization, da tsarin da ke magance acid da chlorides. Misali, ƙarfen Ni-Cr suna da kyakkyawan juriya ga iskar shaka a yanayin zafi mai yawa, yayin da ƙarfen Ni-Mo suka yi fice wajen rage muhalli da wasu mafita na acidic. Walda waɗannan ƙarfe yana buƙatar kiyaye abubuwan da ke cikin ƙarfe don kiyaye juriya mafi kyau ga tsatsa.
2. Kalubale na musamman a walda nickel
Gabaɗaya, ƙarfen nickel yana da ƙarancin ƙarfin lantarki na thermal fiye da ƙarfen carbon da kuma babban adadin faɗaɗa zafi. Wannan haɗin yana haifar da ƙarin yawan zafi a yankin walda kuma yana iya ƙara ɓarna. Bugu da ƙari, wasu ƙarfen nickel suna da saurin kamuwa da:
– Fashewa mai zafi (fashewar tauri) saboda rabuwar abubuwa a iyakokin hatsi yayin tauri na ƙarfen walda.
- Sau da yawa gurɓatawa, danshi, ko iskar gas da ta makale yana haifar da porosity.
- Jin hankali ko rage juriyar tsatsa ta gida idan tsarin walda bai yi daidai ba, musamman akan wasu ƙarfe.
– Gurɓatar ƙarfe/carbon daga kayan aikin ƙarfe na iya yin illa ga juriyar tsatsa, musamman a cikin mawuyacin yanayi na sinadarai.
Saboda haka, kula da tsafta, zaɓin cikawa, da sigogin zafi sune mabuɗin.
3. Zaɓin tsarin walda: GTAW, GMAW, SMAW, da SAW
Wasu hanyoyin walda na gama gari don haɗakar nickel a cikin sinadarai na petrochemicals sun haɗa da:
a) GTAW (TIG)
GTAW sau da yawa ita ce hanyar da aka fi so don amfani da bututun da ke wucewa, aikin daidai, da kuma siririn abu. Fa'idodinsa sun haɗa da ingantaccen sarrafa zafi da kuma walda mai tsabta. Sau da yawa ana amfani da kariyar iskar argon mai tsabta; a wasu aikace-aikace, ana iya ƙara helium don inganta shigar ciki.
b) GMAW (MIG) da GMAW mai bugun zuciya
GMAW ya dace da samar da kayayyaki cikin sauri, musamman a fannin ƙera bita. Yanayin bugun zuciya yana taimakawa wajen rage shigar zafi da kuma watsawa, da kuma inganta sarrafawa a wuraren walda masu wahala. Dole ne a adana wayar walda kuma a sarrafa ta yadda ya kamata don guje wa gurɓatawa.
c) SMAW (walda mai amfani da lantarki)
Ana amfani da SMAW sosai wajen gyaran filin saboda kayan aikinta masu sauƙi. Duk da haka, dole ne a sarrafa haɗarin ɗaukar hydrogen da slag ta hanyar zaɓar electrode mai kyau, hanyoyin yin burodi na electrode, idan ya cancanta, da kuma dabarun tsaftacewa tsakanin layuka.
d) SAW
SAW yana da tasiri ga faranti masu kauri da dogayen walda, kamar a kan tasoshin matsi ko harsashi. Dole ne zaɓin lanƙwasa da waya su dace don tabbatar da cewa haɗin ƙarfen walda yana kiyaye juriyar tsatsa da ake so.
4. Shirye-shiryen kayan aiki da tsaftace saman
Nasarar walda mai ƙarfe na nickel yana da matuƙar tasiri ta hanyar shirye-shiryen saman ƙasa. Ayyukan da aka saba yi a masana'antar man fetur sun haɗa da:
– Rage mai da man shafawa mai kyau don cire mai/kitse.
– Tsaftace oxide ta amfani da goga na musamman na bakin karfe (kada a yi amfani da goga na carbon steel).
– Amfani da kayan aiki daban-daban: injin niƙa, faifan faifan, da goge ya kamata a keɓe su musamman ga kayan nickel/bakin ƙarfe don hana gurɓatawa.
- Daidaito da kuma kula da gibin da ke tsakanin sassan jiki domin rage haɗarin rashin haɗuwa ko ƙonewa.
Ko da ƙananan gurɓatattun abubuwa na iya haifar da porosity da kuma rage ingancin walda.
5. Zaɓin ƙarfe mai cikawa da dacewa
Bai kamata a yi zaɓin ƙarfe mai cikewa kawai bisa ƙa'idar "kayan da suka yi daidai da abu" ba. A cikin aikin sinadarai na petrochemical, sau da yawa ana zaɓar masu cikewa don inganta juriyar tsagewa da tsatsa. Misalan ƙa'idodi na gabaɗaya:
– Yi amfani da abin cikawa mai juriyar fashewa mai zafi da kuma wani abu mai ƙarfi wanda ke tallafawa ƙarfafawa mai ƙarfi.
– Don walda daban-daban (misali ƙarfen nickel zuwa bakin ƙarfe ko ƙarfe mai kauri), sau da yawa ana zaɓar takamaiman abin cika nickel wanda zai iya jure bambancin faɗaɗa zafi da rage matsalolin narkewa.
– Tabbatar da cewa mai cika ya cika ƙa'idodin AWS/ASME masu dacewa kuma ya cika ƙa'idodin aikin.
A aikace-aikace da yawa, ɓangaren tsatsa ya fi rinjaye fiye da ƙarfin taurin kai, don haka zaɓin cikawa yana nufin ƙwarewar sabis da shawarwarin lamba.
6. Sarrafa shigar da zafi, dumama kafin lokaci, da zafin da ke tsakanin wurare
Ba a buƙatar ƙarin ƙarfe na nickel gaba ɗaya a yanayin zafi mai ƙarfi kamar wasu ƙarfe na ƙarfe, amma kula da zafin jiki har yanzu yana da mahimmanci:
– Yawan shigar zafi zai iya faɗaɗa HAZ (yankin da zafi ke shafa), ƙara karkacewa, da kuma ƙara yiwuwar rabuwa wanda ke haifar da fashewar zafi.
– Ya kamata a kiyaye zafin da ke tsakanin hanyoyin sadarwa daga yin sama da yawa, ta yadda za a iya sarrafa tsarin da kuma juriyar tsatsa.
– Sau da yawa ana amfani da dabarun wucewa da yawa tare da saitunan wutar lantarki/ƙarfin lantarki mai ɗorewa akan faranti masu kauri don kiyaye inganci.
Yawanci ana ƙayyade ainihin sigogi ta hanyar WPS (Tsarin Walda) kuma ana gwada su ta hanyar PQR (Rikodin Cancantar Tsarin Aiki).
7. Dabaru na walda don rage lahani
Wasu dabarun aiki waɗanda galibi ake amfani da su wajen walda nickel don sinadarai masu amfani da man fetur:
– Ana fifita beads ɗin Stringer fiye da saƙa mai faɗi, don rage yawan zafi da kuma rage rabuwa.
– Tsaftace layukan da ke tsakanin layukan yana da matuƙar muhimmanci, musamman a SMAW da SAW, don hana haɗa tarkace.
– Tsarin dakatarwa da farawa: dole ne a cika ramin yadda ya kamata domin hana tsagewar ramin.
– Gyaran baya a kan walda bututun GTAW (tare da argon) don kiyaye tushen bead ɗin ba tare da iskar shaka ba.
- Amfani da iskar gas mai inganci da kuma tabbatar da cewa babu wani ɓuɓɓuga da ke haifar da iskar shaka ko porosity.
8. Maganin zafi bayan walda (PWHT) da kuma la'akari da karafa
Ba duk ƙarfen nickel ba ne ke buƙatar PWHT. A lokuta da yawa, PWHT na iya haifar da hazo a wasu matakai, wanda zai iya rage juriyar tsatsa ko tauri, ya danganta da nau'in ƙarfen. Saboda haka:
– Ana yin PWHT ne kawai lokacin da lambar (ASME) ko ƙira ta buƙata, ko kuma lokacin da wani kayan aiki ya buƙaci hakan.
- Kimanta haɗarin ruwan sama na lokacin carbide/intermetallic ya kamata ya yi la'akari da zafin sabis da muhallin da ke lalata iska.
– Don wasu aikace-aikace, ana iya buƙatar a yi amfani da maganin zafi na musamman ko kuma a yi amfani da shi a wurare masu dacewa, amma yawanci ana yin hakan ne a wurin da ya dace kuma bisa ga ƙa'idodin kayan.
9. Dubawa, gwaji da ƙa'idodi da aka yi amfani da su
A fannin sinadarai masu amfani da man fetur, walda akan kayan nickel gabaɗaya tana bin Sashe na IX na ASME don hanyoyin aiki da cancantar walda, da Sashe na VIII na ASME (jijiyoyin matsi) ko B31.3 (bututun tsari). Hanyoyin dubawa na yau da kullun sun haɗa da:
- Gwajin gani (VT) don duba siffar beads, yankewa a ƙasa, da kuma haɗuwa.
– PT (Gwajin Juyawar Ruwa) yana da tasiri wajen gano fasawar saman abubuwa a cikin kayan da ba su da ƙarfe.
- RT/UT don gano lahani na ciki kamar porosity, rashin haɗuwa, ko haɗa slag.
- Ana iya buƙatar ƙarin gwaje-gwaje kamar auna ferrite (idan ya dace), gwajin tauri, ko gwajin tsatsa dangane da aikin.
Ingancin takardu (WPS, PQR, WPQ, gano kayan aiki, adadin zafi) shi ma yana da matukar muhimmanci a ayyukan man fetur.
10. Kesimpulan
Dabaru na walda na ƙarfe na nickel don masana'antar man fetur suna buƙatar bin ƙa'idodin tsafta, zaɓin tsari da cikawa, da kuma sarrafa shigar da zafi. Alloys na nickel suna ba da kyakkyawan aiki a cikin yanayin gurɓatawa da zafi mai yawa, amma yanayinsu ga gurɓatawa da fashewa mai zafi yana buƙatar ƙira mai tsauri da aiwatar da hanyoyin walda. Ta hanyar aiwatar da WPS mai kyau, sarrafa sigogi, dabarun walda mai kyau, da kuma cikakken dubawa daidai da ƙa'idodin ASME, haɗin haɗin da aka yi da nickel na iya samun aminci na dogon lokaci da rage haɗarin gazawar kayan aiki mai mahimmanci a wuraren man fetur.
Idan kuna so, zan iya tsara wannan labarin don ya zama mafi fasaha ta hanyar haɗa misalai na WPS (wurin yanzu/ƙarfin lantarki, nau'in iskar gas mai karewa, matsakaicin interpass), ko mai da hankali kan wani takamaiman ƙarfe kamar Inconel 625 ko Hastelloy C-276.
