Q: Kutshanje siqalile ukwenza umsebenzi ofuna ukuba ezinye izinto zenziwe ngentsimbi engagqwaliyo yebanga lama-304, edityaniswe yodwa kunye nentsimbi ethambileyo. Sifumene iingxaki zokuqhekeka kwintsimbi engagqwaliyo ukuya kwintsimbi engagqwaliyo ukuya kuthi ga kwi-1.25″ ubukhulu. Kukhankanyiwe ukuba sinenani eliphantsi le-ferrite. Ungachaza ukuba yintoni le kwaye ungayilungisa njani?
A: Lo ngumbuzo olungileyo. Ewe, singakunceda uqonde ukuba kuthetha ukuthini ukubalwa kwe-ferrite ephantsi kunye nendlela yokukuthintela.
Okokuqala, makhe sihlolisise inkcazo yentsimbi engagqwaliyo (SS) kunye nendlela i-ferrite enxulumene ngayo namalungu adibeneyo. Intsimbi emnyama kunye nee-alloys ziqulethe intsimbi engaphezulu kwe-50%. Oku kuquka zonke iintsimbi zekhabhoni kunye neentsimbi ezingagqwaliyo kunye namanye amaqela achaziweyo. I-Aluminiyam, ubhedu kunye ne-titanium azinazo intsimbi, ngoko ke ziyimizekelo emihle yee-alloys ezingezizo ii-ferrous.
Izinto eziphambili zale alloy yintsimbi yekhabhoni ene-90% yentsimbi kunye ne-SS ene-70 ukuya kwi-80% yentsimbi. Ukuze ihlelwe njenge-SS, kufuneka ibe ne-11.5% ye-chromium eyongeziweyo ubuncinane. Amanqanaba e-Chromium angaphezu kweli nani liphantsi akhuthaza ukwakheka kweefilimu ze-chromium oxide kwiindawo zentsimbi kwaye athintele ukwakheka kwe-oxidation efana nomhlwa (i-iron oxide) okanye ukugqwala okubangelwa kukuhlaselwa ngamakhemikhali.
I-SS yahlulwe kakhulu ngamaqela amathathu: i-austenite, i-ferrite kunye ne-martensite. Igama labo livela kwisakhiwo sekristale yobushushu begumbi esibenzayo. Elinye iqela eliqhelekileyo yi-duplex SS, eliyibhalansi phakathi kwe-ferrite kunye ne-austenite kwisakhiwo sekristale.
Iiklasi ze-Austenitic, uthotho lwe-300, ziqulathe i-16% ukuya kwi-30% ye-chromium kunye ne-8% ukuya kwi-40% ye-nickel, ezenza isakhiwo sekristale ye-austenitic ikakhulu. Ukukhuthaza ukwakheka komlinganiselo we-austenite-ferrite, iziqinisi ezifana ne-nickel, ikhabhoni, i-manganese kunye ne-nitrogen zongezwa ngexesha lenkqubo yokwenza intsimbi. Amanye amanqanaba aqhelekileyo yi-304, 316 kunye ne-347. Inika ukumelana okuhle nokugqwala; isetyenziswa kakhulu ekutyeni, kwiinkonzo zeekhemikhali, kwiimveliso zamayeza nakwizicelo ze-cryogenic. Ulawulo lokwakheka kwe-ferrite lubonelela ngokuqina okuhle kakhulu kubushushu obuphantsi.
I-Ferritic SS yi-400 series grade enemagnethi epheleleyo, iqulethe i-11.5% ukuya kwi-30% ye-chromium, kwaye inesakhiwo sekristale esiphambili se-ferritic. Ukukhuthaza ukwakheka kwe-ferrite, izibambisi ziquka i-chromium, i-silicon, i-molybdenum, kunye ne-niobium ngexesha lokuveliswa kwentsimbi. Ezi ntlobo ze-SS zihlala zisetyenziswa kwiinkqubo zokukhupha umoya kwiimoto kunye nezityalo zamandla kwaye zinezicelo ezilinganiselweyo zobushushu obuphezulu. Iintlobo ezininzi ezisetyenziswa rhoqo yi-405, 409, 430 kunye ne-446.
Iindidi zeMartensitic, ezichongiweyo luluhlu lwama-400 olufana ne-403, 410 kunye ne-440, zinobunewunewu, ziqulathe i-11.5% ukuya kwi-18% ye-chromium, kwaye zine-martensite njengesakhiwo sekristale. Olu didi lunexabiso eliphantsi legolide, nto leyo eyenza ukuba zingabi naxabiso liphantsi ukuvelisa. Zibonelela ngokumelana nokugqwala; amandla agqwesileyo; kwaye zisetyenziswa rhoqo kwiitafile, izixhobo zamazinyo nezotyando, izitya zokupheka, kunye nezinye iintlobo zezixhobo.
Xa ushisela i-SS, uhlobo lwe-substrate kunye nokusetyenziswa kwayo okusebenzayo kuya kugqiba ukuba yeyiphi intsimbi yokuzalisa efanelekileyo onokuyisebenzisa. Ukuba usebenzisa inkqubo yokukhusela igesi, unokufuna ukunika ingqalelo ekhethekileyo kwimixube yegesi yokukhusela ukuthintela iingxaki ezithile ezinxulumene nokushisela.
Ukuze udibanise i-304 kuyo, uya kufuna i-electrode ye-E308/308L. I-“L” imele ikhabhoni ephantsi, enceda ekuthinteleni ukubola phakathi kweegranular. Ezi electrode zinomxholo wekhabhoni ongaphantsi kwe-0.03%; nantoni na engaphezulu koku inyusa umngcipheko wekhabhoni ukuya kwimida yeenkozo kwaye idityaniswe ne-chromium ukwenza ii-carbides ze-chromium, nto leyo enciphisa ngempumelelo ukuxhathisa ukubola kwentsimbi. Oku kuyacaca ukuba ukubola kwenzeka kwindawo echaphazelekileyo kubushushu (HAZ) yamalungu e-SS welded. Enye into eqwalaselwayo kwi-L grade SS kukuba zinamandla aphantsi okutyhafa kumaqondo obushushu aphezulu kunamanqanaba e-SS ngqo.
Ekubeni i-304 iluhlobo lwe-SS oluyi-austenitic, i-weld metal ehambelanayo iya kuba nenxalenye enkulu ye-austenite. Nangona kunjalo, i-electrode ngokwayo iya kuba ne-ferrite stabilizer, efana ne-molybdenum, ukukhuthaza ukwakheka kwe-ferrite kwi-weld metal. Abavelisi badla ngokudwelisa uluhlu oluqhelekileyo lwe-ferrite kwi-weld metal. Njengoko bekutshiwo ngaphambili, ikhabhoni si-austenitic stabilizer enamandla, kwaye ngenxa yezi zizathu kubalulekile ukuyithintela ukuba ingongezwa kwi-weld metal.
Amanani e-Ferrite athathwe kwi-Schaeffler diagram kunye ne-WRC-1992 diagram, ezisebenzisa iifomula ezilinganayo ze-nickel kunye ne-chromium ukubala ixabiso, elithi xa lidwetshwe kwi-diagram livelise inani eliqhelekileyo. Inani le-ferrite eliphakathi kwe-0 kunye ne-7 lihambelana nepesenti yevolumu yesakhiwo se-ferrite crystal esikhoyo kwi-weld metal; nangona kunjalo, kwiipesenti eziphezulu, inani le-ferrite liyanda ngesantya esiphezulu. Khumbula ukuba i-ferrite kwi-SS ayifani ne-carbon steel ferrite, kodwa yi-phase ebizwa ngokuba yi-delta ferrite. I-Austenitic SS ayinazo iinguqu zesigaba ezinxulumene neenkqubo zobushushu obuphezulu ezifana nonyango lobushushu.
Ukwakheka kwe-ferrite kuyathandeka kuba ithambile kakhulu kune-austenite, kodwa kufuneka ilawulwe. Inani eliphantsi le-ferrite linokwenza ii-welds ezinokumelana nokugqwala okuhle kwezinye iinkqubo, kodwa zichaphazeleka kakhulu kukuqhekeka okushushu ngexesha lokuwelda. Kwiimeko zokusetyenziswa ngokubanzi, inani le-ferrite kufuneka libe phakathi kwe-5 ne-10, kodwa kwezinye iinkqubo kungafuneka amaxabiso aphantsi okanye aphezulu. Ii-ferrites zinokuqinisekiswa ngokulula emsebenzini kusetyenziswa isalathisi se-ferrite.
Ekubeni uthe uneengxaki zokuqhekeka kunye nenani eliphantsi le-ferrite, kufuneka ujonge i-filler metal yakho kwaye uqinisekise ukuba ivelisa inani elaneleyo le-ferrite - malunga ne-8 kufuneka incede. Kwakhona, ukuba usebenzisa i-flux cored arc welding (FCAW), ezi zintsimbi ze-filler zihlala zisebenzisa i-100% carbon dioxide shielding gas okanye i-75% argon/25% CO2 mixture, enokubangela ukufunxwa kwekhabhoni kwi-weld metal. Unganqwenela ukutshintshela kwinkqubo ye-gas metal arc welding (GMAW) kwaye usebenzise i-98% argon/2% oxygen mixture ukunciphisa amathuba okuthathwa kwekhabhoni.
Ukuze udibanise i-SS kwintsimbi yekhabhoni kufuneka usebenzise izinto zokugcwalisa ze-E309L. Le ntsimbi yokugcwalisa isetyenziselwa ngokukodwa ukuwelda iintsimbi ezahlukeneyo kwaye yenza inani elithile le-ferrite emva kokuba intsimbi yekhabhoni ixutywe kwi-weld. Ekubeni ikhabhoni ethile ifunxwa kwintsimbi yekhabhoni, iziqinisi ze-ferrite zongezwa kwintsimbi yokugcwalisa ukuze kuthintelwe ukuthambekela kwekhabhoni ekwenzeni i-austenite. Oku kuya kunceda ukuthintela ukuqhekeka kobushushu kwizicelo zokudibanisa.
Ngamafutshane, ukuba ufuna ukususa imifantu eshushu kwi-austenitic SS welded joints, qinisekisa i-ferrite filler metal efanelekileyo kwaye ulandele indlela elungileyo yokuhlanganisa. Gcina ubushushu bungaphantsi kwe-50 kJ/intshi, gcina amaqondo obushushu aphakathi ukuya kwaphantsi, kwaye uqinisekise ukuba ii-solder joints azinazo naziphi na iingozi ngaphambi kokuba zifakwe kwi-soldering. Sebenzisa i-gauge efanelekileyo ukuqinisekisa ubungakanani be-ferrite kwi-welded joint, ujonge i-5 ukuya kwi-10.
I-WELDER, eyayisakuba yi-Practical Welding Today, ibonisa abantu bokwenyani abenza iimveliso esizisebenzisayo nesisebenza nazo yonke imihla. Le magazini ikhonze uluntu oludibanisa iintsimbi eMntla Melika kangangeminyaka engaphezu kwama-20.
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