mim abu bakin karfe 17-4

Bayanin MIM 17-4 PH

Dangane da ma'aunin AISI 17-4 PH, MIM 17-4 PH shine hazo mai taurin bakin karfe. An bambanta shi ta hanyar haɗuwa da juriya na lalata da halayen injiniya.

Daya daga cikin mafi yadu amfani MIM kayan a cikin karfe allura gyare-gyaren shine 17-4 PH bakin karfe. Wannan ƙarfe yana da babban haɗin juriya na lalata, taurin, da ƙarfi. Rukunin hadaddun tare da kyakkyawan ƙarfi ana samun su ta hanyar kyawawan halaye na 17-4. Bugu da ƙari kuma, ana aiwatar da hardening na biyu yayin aikin sintiri ta hanyar gyara wasu sigogi.

Tun da 17-4 PH yana tsayayya da lalata kamar 304L, ana amfani dashi akai-akai a aikace-aikacen da ke buƙatar kaddarorin inji.

Bugu da ƙari, MIM-17-4 PH an gano ta UNS S17400, AISI 630, ASTM A564, AMS 5643, da bakin karfe 17-4 PH.

 

Haɗin Sinadaran

Abubuwan sinadaran Bakin Karfe 17-4 an jera su a ƙasa, tare da abubuwa da adadin nauyin nauyin su:

• Iron (Fe):Ma'auni (sauran rabo)
• Nickel (Ni):3.00-5.00%
• Silicon (Si):1.00%
• Carbon (C):0.07%
• Chromium (Cr):15.50-17.50%
• Niobium (Nb):0.15-0.45%
• Manganese (Mn):1.00%
• Copper (Cu):3.00-5.00%
• Sulfur (S):0.03%

Abun da ke ciki yana tabbatar da ƙarfin kayan, juriya na lalata, da sauran kaddarorin da suka dace da aikace-aikacen masana'antu daban-daban.

MIM 17-4 PH bakin karfe yawanci yana da halayen injina waɗanda suka fi 10-25% muni fiye da aikin 17-4 PH. Abubuwan farko sun haɗa da:

Rashin lahani ya haɗa da daɗaɗɗen ƙazantar carbon, riƙon pores, da hatsi.
Asarar abubuwan da ke haifar da evaporation: Cr, Cu, da Ni.
Haɗin rashin tsarki: O, C, da N.

Tare da jinkirin sintering, lokaci mai siffar cubic austenite yana daidaita da abubuwan carbon da nitrogen. A gefe guda, cubic delta ferrite mai tushen jiki zai ƙara saurin sintering. Bakin karfe 17-4PH yana jure yanayin hazo wanda ke haifar da babban tauri da ƙarfi, yayin da ragowar delta-ferrite yana rage ƙarfi. Bugu da ƙari, martensite yana faruwa a lokacin lokacin sanyaya bayan sintering.

Maɓalli mai mahimmanci na samfuran MIM shine oxygen. Yankin farko na bakin karfe foda mai rufi tare da oxides yana da girma, kuma adadin oxygen ya bambanta dangane da hanyar samar da foda. Matsakaicin matakan iskar oxygen a cikin sassan MIM 17-4 PH suna haifar da rashin juriya na lalata da ƙarancin halayen injina tunda waɗannan oxides zasu ɗauke ikon chromium na hana lalata.

 

Abubuwan Halitta

Ƙwararren dabara don ƙirƙirar ƙaƙƙarfan sassa na bakin karfe mai girma shine MIM. Mafi girman zafin jiki, ƙimar dumama, yanayi, tsawon lokacin riƙewa, da girman ƙwayar foda duk suna shafar yadda bakin karfe 17-4 PH sinters. Dalilai da yawa suna yin tasiri ga abun da ke ciki na 17-4 PH gami, wanda hakan ke tasiri kan matakan microstructure, halayen ɓarna, da halaye na ƙarshe. Nitrogen daga yanayin tsari, oxygen daga foda ko yanayi, da carbon daga foda ko ɗaure su ne abubuwan farko.

 

Madaidaicin ma'auni na ƙarfi, taurin, da juriya na lalata ya sa 17-4 PH ya zama sanannen zaɓi. Kayayyaki a fagagen na'urorin lantarki, likitan hakora, likitanci, da sararin samaniya suna samun haɗaɗɗun halaye masu sha'awa bayan maganin zafi. bambanta bisa ga abun da ke ciki, tare da canje-canje a cikin Fe, Ni, Cu, da Cr. Yanayin zafin jiki na solidus yana kusa da 1405 ° C, kuma na liquidus yana kusan 1440 ° C. Halayen injiniya suna amsawa ga maganin zafi; karaya elongation jeri daga 8 zuwa 14%, yawan amfanin ƙasa ƙarfi jeri daga 760 zuwa 1240 MPa, tensile ƙarfi jeri daga 1000 zuwa 1340 MPa, da taurin kai 43 HRC.

 

Haɗin keɓaɓɓen ƙarfi, taurin, da juriya na lalata yana sa 17-4 PH bakin karfe ya zama zaɓin da aka fi so a cikin masana'antar allurar ƙarfe. Bakin karfe na martensitic wanda aka fi yawan hazo mai taurare shine 17-4 PH.

• Babban ƙarfi
• Matukar wuya
• Kyakkyawan juriya ga lalata
• Tauri ga karaya
• halaye na zafi magani da waldi

 

Tasirin Binder da Debinding

Don bakin karfe 17-4 PH allurar gyare-gyaren allura, ana amfani da tsarin ɗaure da yawa; Mafi shaharar su sune 60% filler, 30% kashin baya, da 10% surfactant.

Saboda abubuwan haɗin da aka bari zasu canza oxygen na ƙarshe ko matakan carbon, ƙaddamarwa yana da tasiri akan halaye na ƙarshe. De-polymerization ko cire sauran ƙarfi shine matakin farko na ƙaddamarwa; misali, paraffin kakin zuma yana narkewa a cikin heptane, kuma polythylene glycol yana narkewa cikin ruwan zafi. Bugu da ƙari, ana amfani da fuming nitric acid a cikin ƙaddamarwa na catalytic don cire polyoxymethylene. Hanya mafi kyau don cire abin ɗaure a mataki na biyu na ƙaddamarwa shine riƙe shi a 600 zuwa 1000 ° C a cikin yanayin hydrogen. Wani lokaci ana kiran wannan lokaci azaman matakin farawa.

 

Tasirin Ma'auni

Yawancin masu canji suna yin hulɗa yayin sintiri na bakin karfe 17-4 PH don ayyana ƙimar ƙarshe, lokaci, microstructure, da halaye. Abubuwan farko guda huɗu na ƙididdigar ƙididdiga sune jiyya na zafi, yanayi mai banƙyama, ƙaddamarwar iskar oxygen na farko, da girman barbashi.

Matsakaicin zafin jiki yana da mafi tasiri akan ɗimbin yawa.

 

Girman barbashi

Yaduwar sararin sama shine tsarin da haɗin gwal na farko yayin sintering ke faruwa; ƙaramin barbashi tare da yanki mafi girma zai ƙarfafa haɗin farko. Za'a maye gurbin mannewar barbashi na kashin baya ta hanyar haɗin kai da yatsa da zarar pyrolysis mai ɗaure ya faru. Yadawa iyakar hatsi yana buƙatar haɓaka wuyan wuya yayin da haɗin kai tsakanin barbashi na ƙarfe yana ƙaruwa don ƙirƙirar iyakokin hatsi tsakanin barbashi. Lokacin da iyakar hatsi ta yi girma, girman hatsin yana taka muhimmiyar rawa wajen raguwa lokacin da raguwa ya fara, kuma yana da tasiri mai tasiri a kan ƙimar ƙima. Koyaya, tasirin girman ɓangarorin farko na iya fuskantar ta ta mafi girman yanayin zafi ko tsayin lokacin riƙewa.

 

Yanayin

A cikin bakin karfe, daidaitattun zaɓuɓɓukan mahalli na sintering sun haɗa da vacuum, hydrogen, nitrogen, hydrogen-nitrogen, da argon-hydrogen.


Shahararrun yanayi guda biyu mafi mashahuri don bakin karfe 17-4 PH sune hydrogen da vacuum. Akwai faɗuwar oxide mai gani lokacin da aka ƙara carbon. Dukansu silicon da chromium na iya ɗaukar oxygen ba tare da ƙarar carbon na graphite ba. Ragewar oxide yana faruwa lokacin da zafin jiki yayi girma kuma matakin hydrogen yana da girma; ƙananan raɓa zai tabbatar da wannan tsari. Rashin iskar shaka mai sanyi wanda ke faruwa bayan sintiri zai haifar da suturar siliki, baƙin ƙarfe, da chromium wanda ke tsayayya da lalata.

A matsayin mai ƙarfi austenite stabilizer, nitrogen yana da tasiri a kan ci gaban martensite da kuma halaye na ƙarshe na bakin karfe. Yayin da yake sanyi, nitrogen, wanda ke narkewa a cikin austenite, yana haɓaka kamar Cr2N. chromium a cikin yankin iyakar hatsi zai ƙare ta wannan hazo, wanda zai haifar da lalatawar gida da sauri. A sakamakon haka, dole ne mu hana nitrogen daga shiga cikin sararin samaniya kuma mu sanyaya abubuwan da ke ƙasa da 900 ° C a cikin taki na 200 ° C a minti daya. a cikin bakin karfe 17-4 PH don hana samar da chromium nitride.

Graphite kuma yana samar da ƙananan matsi na carbon monoxide a cikin tanderu, wanda shine dalilin da ya sa graphite vacuum furnaces ke samun nasara a cikin vacuum sintering. A 1300 ° C da ƙananan matsa lamba CO na 0.001, zai iya canza chromium oxide zuwa chromium.

 

 

Zazzabi da Yawan zafi

Yawan zagayowar zagayawa sun haɗa da kawar da ƙazanta da matakan ƙonawa waɗanda ke haifar da dumama da riƙewa a yanayi daban-daban. Don rage ƙazanta, madaidaicin zafin jiki yana kusa da 1000 ° C, yayin da na ƙarshe cire polymer, yana kusa da 600 ° C.

Bakin karfe 17-4PH yana fuskantar raguwar raguwa a cikin gwajin dilatometry a matsakaicin ƙimar kusan 1250 ° C, yayin da cikakken yawa (98%) yana buƙatar matsakaicin zafin jiki na 1300 ° C. Copper da chromium, duk da haka, za su ƙafe a waɗannan yanayin zafi mai zafi, watakila haifar da asarar maganin zafi da juriya na lalata.

 

Bugu da ƙari, haɗin delta-ferrite yana taimakawa ta yanayin zafi mafi girma; ta hanyar saurin yaduwa, wannan lokaci zai taimaka a cikin ƙarar ƙima. Farin yanki na delta-ferrite da wurare masu duhu na pores oxide madauwari ana iya gani a cikin jadawali na ƙaramin tsari na MIM 17-4PH a cikin sintering.

Tsarin microstructure na 1260 SS17-4 MIM

 

Sarrafa Carbon

A yayin aiwatar da sintering, carbon shine wani austenite stabilizer. Za a sami ƙarfi mafi girma da taurin tare da ƙarancin riƙe abubuwan abun ciki na carbon a cikin 17-4, ƙasa da kashi 0.1 nauyi. Bakin karfe 17-4 PH's matakai, densification, da na inji duk za a yi tasiri ta hanyar carbon abun ciki canji.

 

Atomized foda na tsarin MIM, ragowar ɗaure, sake zagayowar sake zagayowar, mahalli mai ban sha'awa, fara iskar oxygen, da mafi girman zafin jiki wasu daga cikin masu canji da ke shafar matakin carbon. Babban abin da ke tabbatar da babban abun ciki na carbon yayin sintering shine matakin farko na oxygen. Alal misali, 0.03% carbon yana ɓacewa yayin da ake yin hydrogen sintering na 17-4 gas atomized powders a 1343 ° C. Bugu da ƙari, musamman a ƙananan yanayin zafi, ragowar ɗaure kuma na iya haifar da gurɓataccen carbon.

A cikin hydrogen da vacuum sintering, ƙarfin tensile na bakin karfe 17-4 yana tasiri da adadin carbon da aka riƙe. A cikin ko dai H900 ko H1100 magani mai zafi, ko kuma a daidaitaccen sintering a 1300 zuwa 1360°C. Hoton da ke gaba yana kwatanta yadda ƙarfin ƙarfi ya ragu sosai yayin da abun cikin carbon ke tashi.

 

Kula da Lokaci

A cikin sintering, lokacin riƙewa a mafi girman zafin jiki yana faɗi tsakanin mintuna 60 zuwa 120. daga ƙaƙƙarfan ƙima da zafin jiki da jadawalin lokaci wanda ya biyo baya. Yayin da zafin jiki ya tashi daga 1240 ° C zuwa 1360 ° C, yana nuna ci gaba mai yawa daga 96.3% zuwa 98.3%. Ƙaƙƙarfan ɓangarorin ɓangarorin sun sami cikakken yawa (98%), bayan mintuna 60 na riƙewa. An cire porosity kuma an rage yawan lalata pore a wannan lokacin. Asarar iyakokin hatsi da gajiyawar porosity sune abubuwan farko.

 

Amfanin MIM 17-4

Babban juriya ga lalata
Maganin zafi mai taurin shekaru
Ƙarfin masana'antu da karko
Fitaccen juriya ga zafi
Mafi dacewa don rikitaccen lissafi na MIM

 

Halayen injina

Dangane da na'urorin tsarin, ana amfani da MIM 17-4 PH. Halayen kwatankwacin da aka fi so sune ƙarfi, taurin, da tsawo. Bugu da ƙari, gajiya, ƙarfin samar da ƙarfi, da taurin karyewa al'amura ne waɗanda masu canji da yawa ke tasiri.

Hoton da ke gaba yana taƙaita matsakaicin sigogi na 17-4 PH bisa la'akari da ƙididdigar ayyukan MIM da yawa. Sintering sigogi suna da alhakin kusan 60% na bambancin kaddarorin.

 

Bisa ga ma'auni na masana'antar MIM, bakin karfe 17-4 PH dole ne ya kasance yana da ƙaramin ƙarfi na 790 MPa, taurin HRC 27 bayan sintiri, da taurin 1070 MPa da 33 HRC bayan maganin zafi. 4% elongation ga duka biyu. Ƙarfin ƙarfi na bakin karfe 17-4PH bayan 1350 ° C sintering da H900 zafi magani ne 1280 MPa ga gas-atomized foda da 1136 MPa ga ruwa-atomized foda. Ya kamata a lura da cewa gas atomized foda zai iya cimma ƙarfin da aka yi da zafi na 1485 MPa tare da 9% elongation.

 

Juriya ga Lalacewa

Nau'o'i huɗu na bakin karfe na sintered (304, 316, 430, da 17-4) ana fuskantar gwajin lalata a cikin yanayi iri-iri. Sakamakon ya nuna cewa 17-4 shine mafi ƙarancin juriya ga waɗannan yanayi. Bugu da ƙari kuma, saboda pores a kan abubuwan da aka haɗa su suna haifar da lalata ta gida ta hanyar maida hankali, kayan aikin da aka yi ya fi tsayayya da lalata fiye da kayan da aka yi. Hydrogen sintering da gas atomized foda su ne shahararrun dabaru guda biyu don inganta juriya na lalata saboda ragowar iskar oxygen na da koma baya.

Juriya na lalata kuma yana da alaƙa da daidaituwar halitta. Idan aka kwatanta da titanium da cobalt gami, bakin karfe 17-4 PH yana da cytotoxicity mai kyau amma ba shi da gasa gabaɗayan biocompatibility.

 

Kasuwar Aikace-aikacen PH na MIM 17-4

Fitattun halayen inji ana ba da su ta bakin karfe 17-4 PH a yanayin zafi sama da 350 ° C. Bugu da ƙari, yana da ɗorewa don duka ƙarfe na gilashi da walda, kuma za a iya rage warping da sikelin ta hanyar dumama a ƙananan zafin jiki na ɗan gajeren lokaci.

Saboda mafi girman lalata da juriya na zafi, sararin samaniya 17-4 bakin karfe babban zaɓi ne don aikace-aikacen sararin samaniya. Babban tsaftataccen foda da ƙima na iya tabbatar da rayuwar samfuran MIM 17-4 kuma rage girman canjin kuskure.

Motoci
Abubuwan da aka fi amfani da su a cikin samar da motoci shine bakin karfe 17-4 saboda yana da sauƙi don sarrafawa zuwa nau'i-nau'i iri-iri. Tare da tsayin daka mai yawa, fasahar gyare-gyaren ƙarfe ta ƙarfe kuma tana ƙara ƙarfinta don hadadden lissafi.

Abokan ciniki
Saboda juriya na musamman na lalata, 17-4 ana amfani dashi sosai a aikace-aikacen mabukaci ta amfani da fasahar MIM. Bugu da ƙari, ƙaƙƙarfan ƙarfi da taurin wannan kayan suna garantin aiki mara kuskure.

A karshe

MIM 17-4 PH yana samun ci gaba mai ban mamaki wajen inganta kaddarorin tsari. Don yawancin aikace-aikacen da suka dace, yana ba da nau'ikan haɗuwa masu ban sha'awa na sintered Properties. Sintering zafin jiki ne na farko ƙaddara na karshe halaye idan aka kwatanta da foda nau'in, barbashi size, kore yawa, riko da duration, da sauran sigogi. Bugu da ƙari kuma, ɓangaren da ke cikin kayan da aka lalata yana rinjayar abubuwan da aka lalata.

A halin yanzu, maganin zafi na bayan-sintering, ƙarancin ƙima, da tsarin halittar lokaci duk suna shafar halaye. Yayin da yawan adadin kuzari ke ƙayyade halaye, Hot Isostatic Pressing (HIP) yana haɓaka su.

Ƙarfe Injection Molding (MIM) yana ƙara haɓaka tare da bakin karfe 17-4 PH. Don ba da ƙarin aikace-aikace don sintered 17-4 PH, JHMIM ya dogara da tushen fasahar MIM.