Bakin Karfe (Bakin Karfe)shi ne taƙaitaccen ƙarfe mai jure acid, kuma matakan ƙarfe waɗanda ke da juriya ga raunin gurɓatattun kafofin watsa labarai kamar iska, tururi, ruwa, ko abubuwan da ba su da ƙarfi ana kiran su bakin karfe.
Ajalin "bakin karfe"Ba wai kawai yana nufin nau'in bakin karfe daya ba ne, amma yana nufin nau'ikan bakin karfe fiye da dari na masana'antu, wanda kowannensu yana da kyakkyawan aiki a cikin takamaiman filin aikace-aikacensa.
Dukkansu sun ƙunshi 17 zuwa 22% na chromium, kuma mafi kyawun ma'aunin ƙarfe kuma sun ƙunshi nickel.Ƙara molybdenum na iya ƙara haɓaka lalata yanayi, musamman juriya ga lalata a cikin yanayi mai chloride.
一.Rarraba bakin karfe
1. Menene bakin karfe da karfe mai jure acid?
Amsa: Bakin karfe shine taƙaitaccen ƙarfe mai jure acid, wanda ke da juriya ga raunin gurɓatattun hanyoyin sadarwa kamar iska, tururi, ruwa, ko kuma yana da bakin karfe.Karfe makin da ake kira karafa mai jurewa acid.
Saboda bambancin nau'in sinadarai na biyun, juriyar lalata su ta bambanta.Bakin karfe na yau da kullun ba shi da juriya ga lalata matsakaicin sinadarai, yayin da karfe mai juriya na acid gabaɗaya bakin ciki.
2. Yadda za a rarraba bakin karfe?
Amsa: Bisa ga kungiyar jihar, shi za a iya raba Martensitic karfe, ferritic karfe, austenitic karfe, austenitic-ferritic (duplex) bakin karfe da hazo hardening bakin karfe.
(1) Martensitic karfe: babban ƙarfi, amma matalauta plasticity da weldability.
Yawan amfani da maki na martensitic bakin karfe ne 1Cr13, 3Cr13, da dai sauransu, saboda high carbon abun ciki, shi yana da high ƙarfi, taurin da kuma sa juriya, amma lalata juriya ne dan kadan matalauta, kuma ana amfani da high inji Properties juriya na lalata.Ana buƙatar wasu sassa na gabaɗaya, kamar maɓuɓɓugan ruwa, ruwan injin tururi, bawul ɗin latsa ruwa, da sauransu.
Ana amfani da irin wannan nau'in karfe bayan quenching da zafin jiki, kuma ana buƙatar annealing bayan ƙirƙira da tambari.
(2) Karfe Ferritic: 15% zuwa 30% chromium.Juriyarsa ta lalata, tauri da walƙiya yana ƙaruwa tare da haɓaka abun ciki na chromium, da juriya ga lalatawar damuwa na chloride ya fi sauran nau'ikan bakin karfe, kamar Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28, da sauransu.
Saboda babban abun ciki na chromium, juriya na lalata da juriya na iskar shaka suna da kyau sosai, amma kayan aikin injinsa da kaddarorin sarrafawa ba su da kyau.Ana amfani dashi mafi yawa don tsarin juriya na acid tare da ɗan damuwa kuma azaman ƙarfe na anti-oxidation.
Irin wannan nau'in karfe zai iya tsayayya da lalatawar yanayi, nitric acid da gishiri bayani, kuma yana da halaye na kyakkyawan juriya mai zafi mai zafi da ƙananan haɓakar haɓakar thermal.Ana amfani da shi a cikin nitric acid da kayan masana'antar abinci, kuma ana iya amfani dashi don yin sassan da ke aiki a yanayin zafi mai zafi, kamar sassan injin turbin gas, da sauransu.
(3) Karfe na Austenitic: Yana dauke da sinadarin chromium sama da kashi 18%, sannan yana dauke da kusan kashi 8% na nickel da karamin adadin molybdenum, titanium, nitrogen da sauran sinadarai.Kyakkyawan aikin gabaɗaya, mai jurewa lalata ta kafofin watsa labarai daban-daban.
Gabaɗaya, ana ɗaukar maganin maganin, wato, ƙarfe yana mai zafi zuwa 1050-1150 ° C, sannan a sanyaya ruwa ko sanyaya iska don samun tsarin austenite na lokaci-lokaci.
(4) Austenitic-ferritic (duplex) bakin karfe: Yana da fa'idodin duka austenitic da ferritic bakin karfe, kuma yana da superplasticity.Austenite da ferrite kowane asusun kusan rabin bakin karfe.
A cikin yanayin ƙarancin abun ciki na C, abun cikin Cr shine 18% zuwa 28%, kuma abun cikin Ni shine 3% zuwa 10%.Wasu karafa kuma sun ƙunshi abubuwa masu haɗawa kamar Mo, Cu, Si, Nb, Ti, da N.
Irin wannan karfe yana da halaye na duka austenitic da ferritic bakin karfe.Idan aka kwatanta da ferrite, yana da mafi girma plasticity da taurin, babu dakin zafin jiki brittleness, muhimmanci inganta intergranular lalata juriya da waldi yi, yayin da rike da baƙin ƙarfe Jikin bakin karfe ne gaggautsa a 475 ° C, yana da high thermal watsin, kuma yana da halaye na superplasticity. .
Idan aka kwatanta da bakin karfe austenitic, yana da babban ƙarfi kuma yana inganta juriya sosai ga lalata intergranular da lalata damuwa na chloride.Bakin karfe Duplex yana da kyakkyawan juriyar lalata kuma shima bakin karfe ne mai ceton nickel.
(5) Hazo hardening bakin karfe: matrix ne austenite ko martensite, da kuma yawan amfani da maki na hazo hardening bakin karfe ne 04Cr13Ni8Mo2Al da sauransu.Bakin karfe ne wanda za'a iya taurare (ƙarfafa) ta hanyar hazo (wanda kuma aka sani da taurin shekaru).
Bisa ga abun da ke ciki, an raba shi zuwa chromium bakin karfe, chromium-nickel bakin karfe da chromium manganese nitrogen bakin karfe.
(1) Bakin karfe na Chromium yana da wasu juriya na lalata (oxidizing acid, Organic acid, cavitation), juriya na zafi da juriya, kuma ana amfani dashi gabaɗaya azaman kayan kayan aiki don tashoshin wuta, sinadarai, da mai.Duk da haka, waldawar sa ba ta da kyau, kuma ya kamata a biya hankali ga tsarin walda da yanayin maganin zafi.
(2) A lokacin walda, chromium-nickel bakin karfe ne hõre maimaita dumama zuwa precipitate carbides, wanda zai rage lalata juriya da inji Properties.
(3) A ƙarfi, ductility, tauri, formability, weldability, sa juriya da kuma lalata juriya na chromium-manganese bakin karfe ne mai kyau.
二.Matsaloli masu wahala a cikin walda bakin karfe da gabatarwar amfani da kayan aiki da kayan aiki
1. Me yasa walda bakin karfe ke da wahala?
Amsa: (1) A zafi ji na bakin karfe ne in mun gwada da karfi, da kuma zama lokaci a cikin zafin jiki kewayon 450-850 ° C ne dan kadan ya fi tsayi, da kuma lalata juriya na weld da zafi-shafi yankin za a tsanani rage;
(2) mai saurin fashewar thermal;
(3) Kariya mara kyau da matsanancin zafi mai zafi;
(4) Matsakaicin faɗaɗa na layi yana da girma, kuma yana da sauƙi don samar da nakasar walda mai girma.
2. Wadanne ingantattun matakan fasaha za a iya ɗauka don walda bakin karfe austenitic?
Amsa: (1) Zaɓi kayan walda a hankali gwargwadon sinadarai na ƙarfen tushe;
(2) Yin walda mai sauri tare da ƙaramin halin yanzu, ƙaramin ƙarfin layi yana rage shigar da zafi;
(3) Sirinrin diamita na walda waya, sandar walda, babu lilo, Multi-Layer Multi-pass waldi;
(4) Tilasta sanyaya kabuwar walda da yankin da zafi ya shafa don rage lokacin zama a 450-850°C;
(5) Kariyar Argon a baya na TIG weld;
(6) The welds a lamba tare da lalata matsakaici an karshe welded;
(7) Passivation jiyya na walda kabu da kuma zafi-shafi yankin.
3. Me ya sa ya kamata mu zabi 25-13 jerin waldi waya da lantarki ga waldi austenitic bakin karfe, carbon karfe da low gami karfe (dissimilar karfe waldi)?
Amsa: Welding dissimilar karfe welded gidajen abinci a haɗa austenitic bakin karfe da carbon karfe da low gami karfe, da weld ajiya karfe dole ne a yi amfani da 25-13 jerin waldi waya (309, 309L) da waldi sanda (Austenitic 312, Austenitic 307, da dai sauransu).
Idan aka yi amfani da sauran abubuwan amfani da bakin karfe na walda, tsarin martensitic da fashewar sanyi za su bayyana akan layin hadewar da ke gefen karfen carbon da karamin karfe.
4. Me yasa m bakin karfe walda wayoyi amfani da 98% Ar + 2% O2 garkuwa gas?
Amsa: A lokacin MIG waldi na m bakin karfe waya, idan tsarki argon gas da ake amfani da garkuwa, da surface tashin hankali na narkakkar pool ne high, kuma weld ne talauci samu, yana nuna wani "humpback" weld siffar.Ƙara 1 zuwa 2% oxygen zai iya rage tashin hankalin saman tafkin narkakkar, kuma kabu mai laushi yana da santsi da kyau.
5. Me yasa saman m bakin karfe waldi waya MIG weld juya baki?Yadda za a magance wannan matsala?
Amsa: Gudun walda na MIG na ƙaƙƙarfan waya mai walƙiya bakin karfe yana da sauri (30-60cm/min).Lokacin da bututun iskar gas mai karewa ya gudu zuwa gaban narkakken wurin tafki, weld ɗin har yanzu yana cikin yanayin zafi mai zafi mai zafi, wanda iska ke daɗawa cikin sauƙi, kuma ana samun oxides a saman.Welds baƙar fata ne.Hanyar wucewa ta pickling na iya cire baƙar fata kuma ta dawo da asalin launi na bakin karfe.
6. Me ya sa m bakin karfe waldi waya bukatar yin amfani da pulsed samar da wutar lantarki cimma jet mika mulki da spatter-free waldi?
Amsa: Lokacin da m bakin karfe waya MIG waldi, φ1.2 waldi waya, a lokacin da na yanzu I ≥ 260 ~ 280A, da jet miƙa mulki za a iya gane;ɗigon juzu'in ɗan gajeren zango ne tare da ƙasa da wannan ƙimar, kuma spatter yana da girma, gabaɗaya ba a ba da shawarar ba.
Ta hanyar amfani da wutar lantarki ta MIG tare da bugun jini, za a iya jujjuya digowar bugun jini daga ƙananan ƙayyadaddun ƙayyadaddun bayanai (zaɓa mafi ƙarancin ko matsakaicin ƙimar bisa ga diamita na waya), walƙiya mara lahani.
7. Me yasa waya mai waldawar bakin karfe mai juyi ke kiyaye ta da iskar CO2 maimakon iskar wutar lantarki?
Amsa: A halin yanzu da ake amfani da juyi-cored bakin karfe waldi waya (kamar 308, 309, da dai sauransu), da walda juyi dabara a cikin walda waya da aka ɓullo da bisa ga waldi sinadaran karafa dauki a karkashin kariya na CO2 gas, don haka a general. , babu bukatar pulsed baka waldi wutar lantarki (The wutar lantarki da bugun jini m bukatar yin amfani da gauraye gas), idan kana so ka shigar droplet mika mulki a gaba, za ka iya amfani da bugun jini samar da wutar lantarki ko na al'ada gas garkuwa waldi model tare da gauraye walda.
Lokacin aikawa: Maris 24-2023