904L wani maras daidaita low carbon high gami austenitic bakin karfe.Ƙarin jan ƙarfe zuwa wannan matakin yana ba shi ingantaccen juriya ga ƙaƙƙarfan rage acid, musamman sulfuric acid.Hakanan yana da juriya sosai ga harin chloride - duka ɓarna / ɓarna da lalata da damuwa.
Wannan daraja ba maganadisu ba ce a cikin kowane yanayi kuma yana da kyakkyawan walƙiya da tsari.Tsarin austenitic kuma yana ba da wannan ƙimar kyakkyawan ƙarfi, har zuwa yanayin zafi na cryogenic.
904L yana da abun ciki mai mahimmanci na sinadarai masu tsada nickel da molybdenum.Yawancin aikace-aikacen da wannan matakin ya yi aiki da kyau yanzu ana iya cika su a cikin ƙananan farashi ta hanyar duplex bakin karfe 2205 (S31803 ko S32205), don haka ana amfani da shi ƙasa da ƙasa fiye da na baya.
Maɓalli Properties
An ƙayyade waɗannan kaddarorin don samfurin birgima (faranti, takarda da nada) a cikin ASTM B625.Irin wannan amma ba dole ba ne kaddarorin da aka ƙayyade don wasu samfuran kamar bututu, bututu da mashaya a cikin ƙayyadaddun su.
Abun ciki
Tebur 1.Abubuwan da aka haɗa don ƙimar 904L na bakin karfe.
| Daraja | C | Mn | Si | P | S | Cr | Mo | Ni | Cu | |
| 904l | min. max. | - 0.020 | - 2.00 | - 1.00 | - 0.045 | - 0.035 | 19.0 23.0 | 4.0 5.0 | 23.0 28.0 | 1.0 2.0 |
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Kayayyakin Injini
Table 2.Mechanical Properties na 904L sa bakin karfe.
| Daraja | Ƙarfin Tensile (MPa) min | Ƙarfin Haɓaka 0.2% Hujja (MPa) min | Tsawaitawa (% a cikin 50mm) min | Tauri | |
| Rockwell B (HR B) | Brinell (HB) | ||||
| 904l | 490 | 220 | 35 | 70-90 na al'ada | - |
| Rockwell Hardness kewayon ƙima na al'ada ne kawai;sauran dabi'u an ƙayyade iyaka. | |||||
Abubuwan Jiki
Table 3.Kaddarorin jiki na yau da kullun don 904L na bakin karfe.
| Daraja | Yawan yawa | Na roba Modulus | Ma'ana Co-eff na Faɗawar thermal (µm/m/°C) | Thermal Conductivity | Takamaiman zafi 0-100°C | Elec Resistivity | |||
| 0-100°C | 0-315 ° C | 0-538°C | A 20 ° C | A 500 ° C | |||||
| 904l | 8000 | 200 | 15 | - | - | 13 | - | 500 | 850 |
Kwatanta Ƙirar Maki
Table 4.Bayani dalla-dalla ga 904L sa bakin karfe.
| Daraja | UNS No | Tsohon Birtaniya | Euronorm | Yaren mutanen Sweden SS | JIS na Japan | ||
| BS | En | No | Suna | ||||
| 904l | N08904 | 904S13 | - | 1.4539 | X1NiCrMoCuN25-20-5 | 2562 | - |
| Waɗannan kwatancen kusan sune kawai.An yi nufin lissafin azaman kwatanta kayan aiki iri ɗayabaa matsayin jadawalin kwatankwacin kwangiloli.Idan ana buƙatar daidai daidai da ƙayyadaddun bayanai na asali dole ne a nemi shawara. | |||||||
Matsaloli masu yuwuwar Madadin
Table 5.Matsakaicin madadin maki zuwa 904L bakin karfe.
| Daraja | Me yasa za'a iya zaɓar shi maimakon 904L |
| 316l | Madadin farashi mai ƙarancin ƙima, amma tare da juriyar lalata da yawa. |
| 6 Mo | Ana buƙatar juriya mafi girma ga ramuka da juriya na lalata. |
| 2205 | Juriya mai kama da lalata, tare da 2205 yana da ƙarfin injiniya mafi girma, kuma a ƙaramin farashi zuwa 904L.(2205 bai dace da yanayin zafi sama da 300 ° C ba.) |
| Super duplex | Ana buƙatar juriya mafi girma, tare da ƙarfin mafi girma fiye da 904L. |
Juriya na Lalata
Ko da yake an samo asali ne don juriya ga sulfuric acid shi ma yana da tsayin daka sosai ga mahalli iri-iri.A PRE na 35 yana nuna cewa kayan yana da kyakkyawar juriya ga ruwan teku mai dumi da sauran yanayin chloride mai girma.Babban abun ciki na nickel yana haifar da mafi kyawun juriya ga lalata lalatawar damuwa fiye da daidaitattun maki austenitic.Copper yana ƙara juriya ga sulfuric da sauran acid masu ragewa, musamman a cikin kewayon "tsakiyar maida hankali".
A mafi yawan mahalli 904L yana da tsaka-tsaki na lalata tsakanin ma'auni austenitic 316L da 6% molybdenum mai alloed sosai da ma'aunin "super austenitic".
A cikin nitric acid mai ƙarfi 904L yana da ƙarancin juriya fiye da maki marasa molybdenum kamar 304L da 310L.
Don matsakaicin juriya na lalatawar danniya a cikin matsuguni masu mahimmanci karfe ya kamata a yi maganin maganin bayan aikin sanyi.
Juriya mai zafi
Kyakkyawan juriya ga hadawan abu da iskar shaka, amma kamar sauran nau'ikan alloyed sosai suna fama da rashin zaman lafiya na tsari (hazo na gaggautuwa kamar sigma) a yanayin zafi mai tsayi.Kada a yi amfani da 904L sama da 400 ° C.
Maganin Zafi
Maganin Magani (Annealing) - zafi zuwa 1090-1175 ° C kuma yayi sanyi da sauri.Ba za a iya taurare wannan darajar ta hanyar maganin zafi ba.
Walda
904L za a iya samun nasarar welded ta duk daidaitattun hanyoyin.Ana buƙatar kulawa yayin da wannan darajar ke daɗaɗɗen austenitic sosai, don haka yana da saurin fashewa, musamman a cikin ƙayyadaddun walda.Bai kamata a yi amfani da zafin zafin jiki ba kuma a mafi yawan lokuta ba a buƙatar maganin zafi bayan walda.AS 1554.6 pre-cancantar Grade 904L sanduna da lantarki don walda na 904L.
Kera
904L babban tsabta ne, ƙarancin sulfur, kuma don haka ba zai yi na'ura da kyau ba.Duk da haka, ana iya sarrafa darajar ta amfani da daidaitattun dabaru.
Lankwasawa zuwa ƙaramin radius ana aiwatar da shi cikin sauri.A mafi yawan lokuta ana yin wannan sanyi.Ba a buƙatar cirewar gaba gabaɗaya, kodayake ya kamata a yi la’akari da shi idan za a yi amfani da ƙirƙira a cikin yanayin da ake tsammanin yanayin lalata mai tsananin damuwa.
Aikace-aikace
Aikace-aikace na yau da kullun sun haɗa da:
• Tsarin sarrafawa don sulphuric, phosphoric da acetic acid
• Tsabar ruwa da sarrafa takarda
• Abubuwan da ke cikin tsire-tsire masu goge gas
• Kayan aikin sanyaya ruwan teku
• Abubuwan matatun mai
• Wayoyi a cikin magudanar ruwa