Welding bakin karfe na bukatar zabi na garkuwa gas don kula da metallurgical abun da ke ciki da kuma hade jiki da kuma inji Properties.Common garkuwar gas abubuwa ga bakin karfe sun hada da argon, helium, oxygen, carbon dioxide, nitrogen, da hydrogen (duba Hoto 1) Wadannan gas suna hade a daban-daban rabo don dace da bukatun daban-daban bayarwa halaye, waya iri, tushe alloys, so dutsen dutse profile da kuma tafiya gudun.
Saboda da matalauta thermal watsin da bakin karfe da in mun gwada da "sanyi" yanayi na short-kewaye canja wurin gas karfe baka waldi (GMAW), da tsari na bukatar wani "tri-mix" gas kunshi 85% zuwa 90% helium (Shi), har zuwa 10 % Argon (Ar) da 2% zuwa 5% Carbon Dioxide, 7-00% cakuda 2. 2-1 / 2% CO2. Babban ƙarfin ionization na helium yana inganta arcing bayan ɗan gajeren lokaci;guda biyu tare da high thermal watsin, da yin amfani da Ya ƙara fluidity na narkakkar pool.The Ar bangaren Trimix samar da general garkuwa da weld kududdufai, yayin da CO2 abubuwa a matsayin reactive bangaren tabbatar da baka (duba Hoto 2 ga yadda daban-daban garkuwa gases shafi weld bead profile).
Wasu gaurayawan ternary na iya amfani da iskar oxygen a matsayin stabilizer, yayin da wasu suna amfani da cakuda He / CO2 / N2 don cimma wannan sakamako.
Babban kuskuren masana'antun yi shine ƙoƙarin gajeriyar kewayawa GMAW bakin karfe tare da cakuda gas iri ɗaya (75 Ar / 25 CO2) azaman ƙarfe mai laushi, yawanci saboda ba sa son sarrafa ƙarin silinda.Wannan cakuda ya ƙunshi carbon da yawa.A gaskiya ma, duk wani iskar gas ɗin da ake amfani da shi don waya mai ƙarfi ya kamata ya ƙunshi matsakaicin 5% carbon dioxide.Yin amfani da adadi mai yawa a cikin wani ƙarfe na carbon-dioxide wanda ba shi da daraja 3% a ƙasa. cessive carbon a cikin garkuwa gas iya samar da chromium carbides, wanda rage lalata juriya da inji Properties.Soot kuma iya bayyana a kan weld surface.
Kamar yadda wani gefen bayanin kula, a lokacin da zabi karafa ga shorting GMAW ga 300 jerin tushe gami (308, 309, 316, 347), masana'antun ya kamata zaži LSi grade.LSi fillers da wani low carbon abun ciki (0.02%) da kuma saboda haka musamman shawarar a lokacin da akwai wani hadarin intergranular lalata.Higher silicon abun ciki inganta wetten da kambi, da kuma inganta weld da flafusion a matsayin flafusion. e.
Ya kamata masana'antun su yi taka tsantsan lokacin amfani da gajerun hanyoyin canja wuri.Incomplete Fusion zai iya haifar da arc extinguishing, yin tsari sub-par for m aikace-aikace.A high girma yanayi, idan da abu zai iya goyi bayan ta zafi shigar (≥ 1/16 inch ne kamar thinnest abu welded ta amfani da bugun jini fesa yanayin), a bugun jini da kuma fesa canja wuri zai zama mafi kyau fesa wurin canja wurin. yana ba da ƙarin daidaituwar haɗuwa.
Wadannan high zafi canja wurin halaye ba ya bukatar Ya garkuwar gas.For fesa canja wuri waldi na 300 jerin gami, wani na kowa zabi ne 98% Ar da 2% reactive abubuwa kamar CO2 ko O2.Wasu gas gaurayawan na iya ƙunsar kananan yawa na N2.N2 yana da mafi girma ionization m da thermal watsin, wanda inganta wetting da kuma damar da sauri tafiya;yana kuma rage murdiya.
Domin pulsed fesa canja wurin GMAW, 100% Ar iya zama wani m zabi.Saboda pulsed halin yanzu stabilizes da baka, da gas ba ko da yaushe bukatar aiki abubuwa.
The narkakken tafkin yana da hankali don ferritic bakin karfe da duplex bakin karfe (50/50 rabo na ferrite zuwa austenite) .Ga wadannan gami, a gas cakuda kamar ~ 70% Ar / ~ 30% Ya / 2% CO2 zai inganta mafi kyau wetting da kuma ƙara da tafiya gudun (duba Figure 3) .Similar gaurayawan za a iya amfani da su weld, amma willd nickel alloys da surface na oxide form 2. CO2 ko O2 ya isa ya kara yawan abun ciki na oxide, don haka masana'antun ya kamata su guje wa su ko kuma su kasance a shirye don ciyar da lokaci mai yawa akan su).Abrasive saboda waɗannan oxides suna da wuyar gaske cewa goga na waya yawanci ba zai cire su ba).
Masu sana'a suna amfani da wayoyi na bakin karfe masu juyi don walƙiya a waje saboda tsarin slag a cikin waɗannan wayoyi yana ba da "shelf" wanda ke goyan bayan tafkin walda kamar yadda yake ƙarfafa. , Ya kamata a lura da cewa mafi girma duk-matsayi waldi gudu da ajiya rates iya rage overall waldi halin kaka. Bugu da kari, da juyi-Cored waya yana amfani da na al'ada m ƙarfin lantarki DC fitarwa, yin asali walda tsarin kasa m da kasa hadaddun fiye da pulsed GMAW tsarin.
Domin 300 da 400 jerin allurai, 100% Ar ya kasance daidaitaccen zabi na gas tungsten arc waldi (GTAW) .Lokacin GTAW na wasu nickel alloys, musamman tare da injiniyoyin injiniyoyi, ƙananan adadin hydrogen (har zuwa 5%) na iya ƙarawa don ƙara yawan saurin tafiya (lura cewa sabanin carbon steels, nickel alloys ba su da saukin kamuwa da su).
Don walda superduplex da superduplex bakin karfe, 98% Ar / 2% N2 da 98% Ar / 3% N2 ne mai kyau zabi, bi da bi. Helium kuma za a iya kara don inganta wettability da game da 30%.Lokacin waldi super duplex ko super duplex bakin karfe, makasudin shi ne don samar da wani hadin gwiwa tare da wani ma'auni microstructure% 550 fercause da kusan ferrite. microstructure ya dogara da yawan sanyaya, kuma saboda TIG weld pool yana kwantar da sauri, wuce haddi ferrite ya rage lokacin da aka yi amfani da 100% Ar. Lokacin da aka yi amfani da cakuda gas mai dauke da N2, N2 yana motsawa cikin tafkin narkakkar kuma yana inganta samuwar austenite.
Bakin karfe yana buƙatar kare bangarorin biyu na haɗin gwiwa don samar da ƙãre weld tare da matsakaicin juriya na lalata.Rashin kare baya zai iya haifar da "saccharification," ko oxidation mai yawa wanda zai iya haifar da gazawar solder.
Tight butt fittings tare da m kyau kwarai Fit ko m abun ciki a baya na dacewa ba zai bukaci goyon bayan gas.A nan, babban batu shi ne don hana wuce kima discoloration na zafi-tasiri yankin saboda oxide ginawa-up, wanda sa'an nan na bukatar inji remover.Technically, idan backside zafin jiki ya wuce 500 digiri Fahrenheit, a garkuwa gas ake bukata don conservativeth Fahrenheit. riƙe.Mai kyau, goyan bayan ya kamata ya kasance ƙasa da 30 PPM O2. Banda shi ne idan bayan weld ɗin za a gouged, ƙasa da walda don cimma cikakkiyar walƙiya.
Gudun gas guda biyu masu goyon bayan zabi sune N2 (mafi arha) da Ar (mafi tsada) .Don ƙananan majalisa ko lokacin da tushen Ar ke samuwa, yana iya zama mafi dacewa don amfani da wannan gas kuma bai dace da ajiyar N2 ba. Har zuwa 5% hydrogen za a iya ƙarawa don rage oxidation.A dama da zaɓuɓɓukan kasuwanci suna samuwa, amma goyon bayan gida da dams tsarkakewa suna da yawa.
Ƙarin 10.5% ko fiye na chromium shine abin da ke ba da bakin karfe Properties na bakin ciki. Tsayawa wadannan kaddarorin yana buƙatar fasaha mai kyau wajen zaɓar gas mai kariya na walda daidai da kuma kare bayan haɗin gwiwa. Bakin karfe yana da tsada, kuma akwai dalilai masu kyau don amfani da shi. Babu wata ma'ana a ƙoƙarin yanke sasanninta lokacin da ya zo ga garkuwar gas ko zabar ma'aunin ƙarfe na ƙarfe don yin aiki tare da iskar gas ko kuma zabar ma'anar ƙarfe don yin aiki tare da wannan ma'ana. ƙwararre lokacin zabar iskar gas da ƙarfe don walda bakin karfe.
Ci gaba da sabuntawa tare da sabbin labarai, abubuwan da suka faru da fasaha akan duk karafa daga wasikunmu na wata-wata da aka rubuta na musamman don masana'antun Kanada!
Yanzu tare da cikakken damar yin amfani da bugu na dijital na Kanada Metalworking, samun sauƙin samun albarkatun masana'antu masu mahimmanci.
Yanzu tare da cikakken damar yin amfani da bugu na dijital na Made in Canada da Welding, sauƙin samun dama ga albarkatun masana'antu masu mahimmanci.