Taƙaice: Kwatancen aiki na Stelite 6 da Stellite 21, yana bayanin yadda abun ciki na carbon da tungsten-versus-molybdenum ke fitar da taurin da taurin ciniki.
Stellite 6 da Stellite 21 su ne nau'in haɗin gwiwa na tushen cobalt mafi yawan lokuta idan aka kwatanta da juna. Tsohuwar gama gari shine a saka Stelite 6 a duk lokacin da rashin tabbas. Wannan al'ada tana da tushe mai ma'ana: Stellite 6 yana da dogon tarihin aikace-aikacen, ingantaccen rubuce-rubuce, da ƙwarewar sarrafawa. Amma a cikin yanayi guda biyu tsoho na iya gabatar da haɗarin da ba dole ba: lokacin da sashin ya ga saurin hawan zafi ko girgizar zafi, da kuma lokacin da ɓangaren ke da bangon bakin ciki ko sashin ya canza.
Stelite 21 yana wanzuwa sosai don magance ƙayyadaddun ƙayyadaddun ƙarfi na Stelite 6 a cikin waɗannan yanayi. Fahimtar cinikin da ke tsakanin su biyun ya fi amfani fiye da haddace wanne ne "mafi kyau."
Bambance-bambancen abun ciki yana haifar da rarrabuwar aikin
Tazarar aiki tsakanin waɗannan allunan ya zo ƙasa zuwa zaɓin abubuwan haɗawa biyu.
Abubuwan da ke cikin Carbon. Stelite 6 yana ɗaukar matakin carbon mai girma sosai. Ƙarƙashin SAE AMS 5387, simintin gyare-gyare na Stellite 6 suna da nau'in ƙima na 60Co-29Cr-4.5W, tare da carbon yawanci a cikin kewayon 0.9-1.4% don samfuran simintin. Ƙarin carbon yana nufin ƙarin hazo mai ƙarfi na carbide, wanda ke ɗaga taurin kai tsaye da juriya. Stellite 21 yana da ƙananan carbon da yawa, tare da abun da ba a sani ba na kusan C ~ 0.25%, Cr 25-30%, Mo 4.5-6.5%, Ni 1.5-3.5%, Ma'auni Co. Ƙananan carbon yana nufin ƙananan ƙarar ƙarar carbide da microstructure wanda ke mamaye matrix na cobalt mai ƙarfi.
Tungsten da molybdenum. Stellite 6 yana amfani da tungsten (W) a matsayin babban mai ƙarfi mai ƙarfi; Stelite 21 ya maye gurbin mafi yawan tungsten da molybdenum (Mo). Molybdenum yana da kusan rabin nauyin atomic na tungsten, don haka a kaso ɗaya nauyin yana ba da gudummawar kusan ninki biyu. Molybdenum kuma yana da alaƙa mai ƙarfi ga carbon kuma yana ƙoƙarin haɓaka samuwar carbide. A cikin Stellite 21, duk da haka, ƙarancin matakin carbon yana iyakance wannan tasirin, kuma sakamakon yanar gizo yana da ƙarancin adadin carbide mai ƙarancin gaske fiye da Stellite 6.
Tare, waɗannan bambance-bambancen guda biyu suna samar da bayanan bayanan aiki daban-daban.
Stellite 6: ƙarancin carbide don musanya juriya na lalacewa
Microstructure na Stellite 6 ya ƙunshi matrix mai ƙarfi na tushen cobalt tare da ingantacciyar rarrabuwar barbashi mai ƙarfi na carbide. Wannan tsarin yana aiki da kyau a ƙarƙashin lalacewa.
Inda ya dace. Fuskokin rufe bawul, hannayen famfo, abubuwan sarrafa slurry, da sassan lalacewa gabaɗaya ƙarƙashin matsakaicin tasiri aikace-aikace ne na Stelite 6 na yau da kullun. Taurinsa yawanci yana faɗuwa a cikin kewayon Rockwell C 37-45, ya danganta da yanayin simintin gyare-gyare da maganin zafi na gaba, wanda ya isa ga mafi yawan matsalolin lalacewa. A cikin yanayin yanayin zafi mai zafi, Stellite 6 kuma yana samar da Layer oxide mai kariya wanda ya danganta da Cr₂O₃ da CoCr₂O₄, tare da ƙarancin oxidation fiye da Stellite 21.
Inda iyaka ya bayyana. Matsakaicin adadin carbide yana da sakamako na gefe: a ƙarƙashin saurin hawan keken zafi ko girgizar yanayin zafi na gida, bambancin haɓakar thermal tsakanin carbides da matrix na iya zama wurin farawa da fashewa. Don sassan sassa na bakin ciki, mafi girman carbon da abun ciki na carbide kuma na iya tayar da haɗarin fashe yayin yin simintin gyare-gyare da injina. Wannan ba yana nufin ba za a iya amfani da Stellite 6 a cikin waɗannan yanayi ba, amma lokacin da gajiyar zafin jiki shine yanayin gazawar mafi girma, ya kamata a kimanta madadin da gaske.
Stellite 21: ƙananan abun ciki na carbide don musanya ga tauri da juriya na thermal gajiya
Stelite 21 yana bin dabaru na ƙira na daban. Ƙananan abun ciki na carbon da ƙari na molybdenum yana rage raguwar ƙarar ƙarar carbide, yana barin matrix mai ƙarfi mai ƙarfi a matsayin lokacin da ke ɗaukar aikin injiniya.
Sakamakon kai tsaye: Ƙunƙarar yanayin ɗaki da tsantsar juriyar lalacewa sun yi ƙasa da Stellite 6, amma tauri, juriya na zafin jiki, da juriya na thermal gajiya sun fi kyau. Taurin simintin simintin yawanci ana ba da rahoto a cikin ƙananan-zuwa-tsakiyar HRC 30s, ƙasa da na Stelite 6 (masu ƙima sun dogara da nau'in samfur da yanayin gwaji - tabbatar da saɓani da bayanan mai siyarwa kafin tantancewa). Amfanin sa ba sa kayan abrasives ba ne amma kiyaye mutuncin tsari a ƙarƙashin hawan keken zafi.
Inda ya dace. An yi amfani da Stellite 21 a cikin injin injin turbin gas, bawul masu aiki masu zafi, masu zafi masu zafi, da ƙwanƙwasa walda waɗanda ke buƙatar hana haɓakar haɓakar thermal. Inda Stellite 6 ke aiki azaman saman saman kuma ana buƙatar matsakaicin Layer, Stellite 21 a tarihi an yi amfani da shi azaman maƙasudi don tausasa bambance-bambancen faɗaɗawar thermal tsakanin ma'aunin ƙarfe da saman Layer Stelite 6. Wani bincike akan F91 karfe substrates tare da Stellite 21 buffer yadudduka, shekaru a 550-650 ° C har zuwa 8,760 hours, samu gagarumin tasiri tauri asara a F91/S21 interface, wanda shine dalilin da ya sa nickel tushen buffer yadudduka ake ƙara fi son a cikin wannan takamaiman aikace-aikace. Wannan yana kwatanta matsayin gami da kyau: ƙimar sa yana cikin tauri a ƙarƙashin takamaiman yanayi, ba a maye gurbin Stellite 6 a ko'ina ba.
Iyaka mai sauƙin mantawa. Stellate 21 yana da iyakacin juriya ga yashwar ɓarke . Saboda ƙarancin carbide yana da ƙasa, matrix yana ba da ƙarancin kariya lokacin da ɓarna masu kaifi suna bugun sauri. Ƙarƙashin yashwar ƙananan kusurwa da lalacewa mai wuya, Stellite 21 yawanci ba shine mafi kyawun zaɓi ba.
Hanya mai aiki da zaɓe
Hanyar da ta biyo baya ta dogara ne akan halayen aiki na gami biyu. Zai iya zama jagorar nunawa ta farko amma bai kamata ya maye gurbin aikin injiniya na takamaiman aikace-aikacen ba.
Juya zuwa Stelite 6 lokacin da:
- Yanayin gazawa mafi rinjaye shine lalacewa ko mannewa, kuma hawan keken zafi ba babban nauyi bane.
- Bangaren yana da kauri mai kauri, kuma ana iya sarrafa hankali lokacin yin simintin gyare-gyare da injina.
- Yanayin zafin sabis yana da girma a cikin yanayi mai oxidizing, kuma Layer oxide mai kariya wani ɓangare ne na ƙira.
- Aikace-aikacen yana da kafaffen tarihin Stelite 6 tare da bayanan gazawar don tunani.
Juya zuwa Stelite 21 lokacin da:
- Sashin yana jujjuya saurin dumama da sanyaya, kuma fashewar gajiyar zafi sanannen haɗari ne.
- Bangaren yana da bangon bakin ciki ko sashe na ba zato ba tsammani ya canza, kuma taurin yana da mahimmanci fiye da ɗanyen taurin.
- Ana buƙatar shimfiɗaɗɗen miƙa mulki tsakanin karfen karfe da mai wuyan fuska don ƙera rashin daidaituwar haɓakar zafi (amma dole ne a kimanta kwanciyar hankali na dogon lokaci).
- The lalacewa inji ne yafi karfe-to-karfe zamiya lalacewa ko cavitation maimakon wuya-barbashi yashwa.
Lokacin da babu tsaftataccen dacewa: Idan aikace-aikacen yana buƙatar duka juriya mai tsauri da kuma kyakkyawan juriya na thermal, Stellite 12 (mafi girman carbon, juriya mafi girma) ko dangin Tribaloy na kayan haɗin gwiwar da ke da ƙarfi na iya zama darajar la'akari, ko gudanarwar thermal na ɓangaren na iya buƙatar a magance shi a matakin ƙira. Waɗannan kwatancen sun wuce wannan kwatancen amma suna cikin nazarin zaɓin kayan matakin farko.
Abin da za a haɗa a cikin RFQ
Ko wanne irin gami da aka zaɓa, mai simintin simintin gyare-gyare da injina yawanci yana buƙatar abubuwan da ke gaba kafin ya ba da fa'ida mai ma'ana:
- Zane-zane na sashi tare da maɓalli masu mahimmanci da buƙatun haƙuri.
- Yanayin sabis: kewayon zafin jiki, matsakaici, da nau'in kaya (sawa, tasiri, hawan keke na thermal).
- Rayuwa da ake tsammani ko yanayin gazawar da aka sani, tare da sashin tarihi idan akwai.
- Matsayin kayan abu, misali ko AMS 5387 ko wani ƙayyadaddun bayanai dole ne a cika su.
- Yawan, tun da guda guda, ƙananan batches, da kuma samar da kundin suna haifar da zaɓuɓɓukan tsari daban-daban.
Don simintin simintin gyare-gyare na tushen cobalt, yana da kyau a tabbatar ko mai siyarwa yana da damar a cikin gida daga yin simintin simintin gyare-gyare ta hanyar gama aikin injin, saboda waɗannan allunan suna aiki da ƙarfi sosai kuma rarrabuwar kai tsakanin hanyoyin yana shafar duka farashi da lokacin jagora.
