T: Kwanan nan mun fara yin wasu ayyuka da ke buƙatar a yi wasu sassan musamman na ƙarfe mai daraja 304, wanda aka haɗa shi da kansa da kuma ƙarfe mai laushi. Mun fuskanci wasu matsalolin fashewa a kan walda na bakin ƙarfe zuwa ƙarfe mai kauri har zuwa inci 1.25. An ambaci cewa muna da ƙarancin adadin ferrite. Za ku iya bayyana menene wannan da kuma yadda za a gyara shi?
A: Wannan tambaya ce mai kyau. Haka ne, za mu iya taimaka muku fahimtar ma'anar ƙarancin adadin ferrite da kuma yadda za a hana shi.
Da farko, bari mu sake duba ma'anar bakin karfe (SS) da kuma yadda ferrite ke da alaƙa da haɗin da aka haɗa. Baƙin ƙarfe da ƙarfe suna ɗauke da ƙarfe fiye da 50%. Wannan ya haɗa da dukkan ƙarfen carbon da bakin ƙarfe da sauran ƙungiyoyi da aka ƙayyade. Aluminum, jan ƙarfe da titanium ba su ƙunshi ƙarfe ba, don haka misalai ne masu kyau na ƙarfe marasa ƙarfe.
Babban sassan wannan ƙarfen ƙarfe shine ƙarfe mai aƙalla kashi 90% na ƙarfe da kuma SS mai kashi 70 zuwa 80% na ƙarfe. Domin a rarraba shi a matsayin SS, dole ne a ƙara masa aƙalla kashi chromium 11.5%. Matakan Chromium sama da wannan mafi ƙarancin iyaka suna haɓaka samuwar fina-finan chromium oxide akan saman ƙarfe kuma suna hana samuwar iskar shaka kamar tsatsa (iron oxide) ko tsatsa da harin sinadarai ke haifarwa.
An raba SS zuwa ƙungiyoyi uku: austenite, ferrite da martensite. Sunansu ya fito ne daga tsarin lu'ulu'u mai zafin ɗaki wanda ya samar da su. Wani rukuni na gama gari shine duplex SS, wanda shine daidaito tsakanin ferrite da austenite a cikin tsarin lu'ulu'u.
Maki na Austenitic, jerin 300, ya ƙunshi chromium 16% zuwa 30% da nickel 8% zuwa 40%, wanda ke samar da tsarin kristal na austenitic mafi yawan gaske. Don haɓaka samuwar rabon austenite-ferrite, ana ƙara masu daidaita abubuwa kamar nickel, carbon, manganese da nitrogen yayin aikin yin ƙarfe. Wasu maki na gama gari sune 304, 316 da 347. Yana ba da kyakkyawan juriya ga tsatsa; galibi ana amfani da shi a abinci, ayyukan sinadarai, magunguna da aikace-aikacen cryogenic. Kula da samuwar ferrite yana ba da kyakkyawan tauri mai ƙarancin zafin jiki.
Ferritic SS wani nau'in 400 ne mai cikakken ƙarfin maganadisu, yana ɗauke da chromium 11.5% zuwa 30%, kuma yana da tsarin crystal mai rinjaye na ferritic. Don haɓaka samuwar ferrite, masu daidaita abubuwa sun haɗa da chromium, silicon, molybdenum, da niobium yayin samar da ƙarfe. Waɗannan nau'ikan SS ana amfani da su sosai a cikin tsarin fitar da hayaki na motoci da cibiyoyin wutar lantarki kuma suna da iyakataccen amfani da zafin jiki mai yawa. Nau'ikan da aka fi amfani da su sune 405, 409, 430 da 446.
Ma'aunin Martensitic, wanda kuma aka gano ta hanyar jerin 400 kamar 403, 410 da 440, suna da maganadisu, suna ɗauke da chromium 11.5% zuwa 18%, kuma suna da martensite a matsayin tsarin lu'ulu'u. Wannan haɗin yana da mafi ƙarancin adadin zinare, wanda ke sa su zama mafi ƙarancin tsada don samarwa. Suna ba da ɗan juriya ga tsatsa; ƙarfi mai kyau; kuma ana amfani da su akai-akai a cikin kayan teburi, kayan aikin haƙori da na tiyata, kayan girki, da wasu nau'ikan kayan aiki.
Lokacin da kake walda SS, nau'in substrate da aikace-aikacensa a cikin sabis zai ƙayyade ƙarfen cikawa da ya dace don amfani. Idan kana amfani da tsarin kariyar iskar gas, ƙila ka buƙaci kulawa ta musamman ga haɗakar iskar gas don hana wasu matsalolin da suka shafi walda.
Don haɗa 304 da kansa, za ku buƙaci lantarki na E308/308L. "L" yana nufin ƙarancin carbon, wanda ke taimakawa hana tsatsa tsakanin granular. Waɗannan lantarki suna da sinadarin carbon ƙasa da 0.03%; duk wani abu da ke sama yana ƙara haɗarin haƙar carbon zuwa iyakokin hatsi da haɗuwa da chromium don samar da chromium carbide, wanda ke rage juriyar tsatsa na ƙarfe. Wannan zai bayyana idan tsatsa ta faru a yankin da zafi ya shafa (HAZ) na haɗin SS da aka haɗa. Wani abin la'akari da shi ga matakin L SS shine cewa suna da ƙarancin ƙarfi a yanayin zafi mai yawa fiye da matakan SS kai tsaye.
Tunda 304 nau'in SS ne na austenitic, ƙarfen walda mai dacewa zai ƙunshi yawancin austenite. Duk da haka, lantarki da kansa zai ƙunshi mai daidaita ferrite, kamar molybdenum, don haɓaka samuwar ferrite a cikin ƙarfen walda. Masana'antun galibi suna lissafa adadin ferrite na yau da kullun don ƙarfen walda. Kamar yadda aka ambata a baya, carbon ƙarfi ne mai daidaita austenitic, kuma saboda waɗannan dalilai yana da mahimmanci a hana shi ƙarawa cikin ƙarfen walda.
An samo lambobin Ferrite daga zane-zanen Schaeffler da zane-zanen WRC-1992, waɗanda ke amfani da dabarun nickel da chromium daidai don ƙididdige ƙimar, waɗanda idan aka zana su akan zane-zanen suna samar da lamba mai daidaitawa. Lambar ferrite tsakanin 0 da 7 ta yi daidai da kashi na girma na tsarin lu'ulu'u na ferrite da ke cikin ƙarfen walda; duk da haka, a cikin mafi girman kashi, adadin ferrite yana ƙaruwa da sauri. Ka tuna cewa ferrite a cikin SS ba iri ɗaya bane da ferrite na ƙarfe na carbon, amma wani lokaci da ake kira delta ferrite. Austenitic SS ba shi da wani canji na lokaci da ke da alaƙa da manyan hanyoyin zafin jiki kamar maganin zafi.
Samuwar ferrite abu ne mai kyau domin yana da ƙarfi fiye da austenite, amma dole ne a sarrafa shi. Ƙananan ƙidayar ferrite na iya samar da walda masu juriya ga tsatsa a wasu aikace-aikace, amma suna da matuƙar saurin kamuwa da tsatsa yayin walda. Don yanayin amfani gabaɗaya, adadin ferrite ya kamata ya kasance tsakanin 5 da 10, amma ga wasu aikace-aikacen ana iya buƙatar ƙarancin ƙima ko mafi girma. Ana iya tabbatar da Ferrites cikin sauƙi akan aikin ta amfani da alamar ferrite.
Tunda kun ambaci cewa kuna da matsalolin fashewa da ƙarancin adadin ferrite, kuna buƙatar yin la'akari da ƙarfen cika ku sosai kuma ku tabbatar yana samar da isasshen adadin ferrite - kusan 8 ya kamata ya taimaka. Haka kuma, idan kuna amfani da walda mai ƙarfi (FCAW), waɗannan ƙarfen cika yawanci suna amfani da iskar gas mai kariyar carbon dioxide 100% ko cakuda argon/25% CO2, wanda zai iya haifar da ɗaukar carbon a cikin ƙarfen walda. Kuna iya son canzawa zuwa tsarin walda mai ƙarfe na gas (GMAW) kuma ku yi amfani da cakuda argon/2% oxygen 98% don rage yiwuwar ɗaukar carbon.
Don haɗa SS zuwa ƙarfen carbon, dole ne ku yi amfani da kayan cika E309L. Wannan ƙarfen cika ana amfani da shi musamman don walda ƙarfe daban-daban kuma yana samar da wani adadin ferrite bayan an narkar da ƙarfen carbon a cikin walda. Tunda ana shaye wasu carbon a cikin ƙarfen carbon, ana ƙara masu daidaita ferrite a cikin ƙarfen cika don magance yanayin carbon na samar da austenite. Wannan zai taimaka wajen hana fashewa mai zafi a aikace-aikacen walda.
A taƙaice, idan kuna son kawar da tsagewar zafi akan haɗin welded SS na austenitic, tabbatar da isasshen ƙarfe mai cika ferrite kuma ku bi kyakkyawan tsarin walda. Ajiye zafin da ke ƙasa da 50 kJ/inch, kula da matsakaicin zafin interpass, kuma tabbatar da cewa haɗin solder ba su da wani gurɓatawa kafin a haɗa su. Yi amfani da ma'auni mai dacewa don tabbatar da adadin ferrite akan haɗin welded, da nufin 5 zuwa 10.
WELDER, wacce a da ake kira Practical Welding Today, tana nuna ainihin mutanen da ke yin kayayyakin da muke amfani da su da kuma waɗanda muke aiki da su kowace rana. Wannan mujallar ta yi wa al'ummar walda hidima a Arewacin Amurka tsawon sama da shekaru 20.
Yanzu da cikakken damar shiga bugu na dijital na The FABRICATOR, samun damar samun albarkatun masana'antu masu mahimmanci cikin sauƙi.
Bugun dijital na Jaridar The Tube & Pipe yanzu ya zama cikakke, wanda ke ba da damar samun albarkatu masu mahimmanci a masana'antu cikin sauƙi.
Ji daɗin cikakken damar shiga bugu na dijital na STAMPING Journal, wanda ke ba da sabbin ci gaban fasaha, mafi kyawun ayyuka da labaran masana'antu don kasuwar tambarin ƙarfe.
Yanzu da cikakken damar shiga bugu na dijital na The Fabricator en Spanish, samun damar samun albarkatun masana'antu masu mahimmanci cikin sauƙi.