Q: Kutshanje siqalile ukwenza umsebenzi ofuna ukuba ezinye izinto zenziwe ngentsimbi engagqwaliyo engama-304, edityaniswe yodwa kwaye idityaniswe nentsimbi ethambileyo. Siye sahlangabezana neengxaki ezithile zokuqhekeka kwentsimbi phakathi kwentsimbi engagqwaliyo kunye nentsimbi engagqwaliyo ukuya kuthi ga kwi-1.25″ ubukhulu. Kukhankanyiwe ukuba sinamanqanaba aphantsi e-ferrite. Ungachaza ukuba yintoni kwaye ungayilungisa njani?
A: Ngumbuzo olungileyo lowo. Ewe, singakunceda uqonde ukuba kuthetha ukuthini i-ferrite ephantsi kunye nendlela yokuyithintela.
Okokuqala, makhe sijonge 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 athile. I-aluminium, i-copper, kunye ne-titanium azinazo intsimbi, ngoko ke ziyimizekelo emihle yee-alloys ezingezizo ii-ferrous.
Izinto eziphambili zale alloy yintsimbi yekhabhoni enomxholo wentsimbi ongama-90% ubuncinane kunye nentsimbi engatyiwayo enomxholo wentsimbi ongama-70 ukuya kuma-80%. Ukuze ihlelwe njenge-SS, kufuneka ibe ne-chromium eyongeziweyo ubuncinane eyi-11.5%. Amanqanaba eChromium angaphezu kweli nani liphantsi akhuthaza ukwakheka kwefilimu ye-chromium oxide kwiindawo zentsimbi kwaye athintele ukwakheka kwe-oxidation efana nomhlwa (i-iron oxide) okanye ukubola kwekhemikhali.
Intsimbi engagqwaliyo yahlulwe kakhulu yangamaqela amathathu: i-austenitic, i-ferritic kunye ne-martensitic. Igama lazo livela kwisakhiwo sekristale kubushushu begumbi apho zenziwe khona. Elinye iqela eliqhelekileyo yintsimbi engagqwaliyo ephindwe kabini, eyibhalansi phakathi kwe-ferrite kunye ne-austenite kwisakhiwo sekristale.
Iiklasi ze-Austenitic, uthotho lwama-300, ziqulathe i-16% ukuya kuma-30% ye-chromium kunye ne-8% ukuya kuma-40% ye-nickel, ezenza isakhiwo sekristale ye-austenitic ikakhulu. Izinto zokuzinzisa ezifana ne-nickel, ikhabhoni, i-manganese, kunye ne-nitrogen zongezwa ngexesha lenkqubo yokwenza intsimbi ukunceda ukwenza umlinganiselo we-austenite-ferrite. Amanye amanqanaba aqhelekileyo angama-304, 316 kunye nama-347. Ibonelela ngokumelana okuhle nokugqwala; isetyenziswa kakhulu kumashishini okutya, amakhemikhali, amayeza kunye ne-cryogenic. Ulawulo lokwakheka kwe-ferrite lubonelela ngokuqina okuhle kumaqondo obushushu aphantsi.
I-Ferritic SS yi-400 series grade enemagnethi epheleleyo, iqulethe i-11.5% ukuya kwi-30% ye-chromium, kwaye inesakhiwo sekristale ye-ferritic ikakhulu. Ukukhuthaza ukwakheka kwe-ferrite, iziqinisi ziquka i-chromium, i-silicon, i-molybdenum kunye ne-niobium ngexesha lokuveliswa kwentsimbi. Ezi ntlobo ze-SS zihlala zisetyenziswa kwiinkqubo zokukhupha umoya kwiimoto kunye nee-powertrains kwaye zinezicelo ezilinganiselweyo zobushushu obuphezulu. Iintlobo ezininzi ezisetyenziswa rhoqo: 405, 409, 430 kunye ne-446.
Iiklasi zeMartensitic, ezikwabizwa ngokuba yi-400 series, ezifana ne-403, 410, kunye ne-440, zinobunewunewu, ziqulathe i-11.5% ukuya kwi-18% ye-chromium, kwaye zinesakhiwo sekristale ye-martensitic. Olu didi lunexabiso eliphantsi legolide, nto leyo eyenza ukuba zingabi naxabiso liphantsi ukuvelisa. Zibonelela ngokumelana nokugqwala, amandla aphezulu, kwaye zisetyenziswa kakhulu kwizixhobo zokutya, amazinyo kunye nezixhobo zotyando, izitya zokupheka, kunye nezinye iintlobo zezixhobo.
Xa ushisela intsimbi engagqwaliyo, uhlobo lwe-substrate kunye nokusetyenziswa kwayo kuya kugqiba intsimbi yokuzalisa efanelekileyo ekufuneka isetyenziswe. Ukuba usebenzisa inkqubo yegesi yokukhusela, unokufuna ukunika ingqalelo ekhethekileyo kwimixube yegesi yokukhusela ukuthintela iingxaki ezithile ezinxulumene nokushisela.
Ukuze udibanise i-304 kuyo, uya kufuna i-electrode ye-E308/308L. U-“L” umele ikhabhoni ephantsi, enceda ekuthinteleni ukubola phakathi kwe-granular. Umxholo wekhabhoni kwezi electrodes ungaphantsi kwe-0.03%, ukuba eli xabiso lidluliwe, umngcipheko wokufakwa kwekhabhoni kwimida yeenkozo kunye nokubophelela kwe-chromium ukwenza ii-carbides ze-chromium uyanda, nto leyo enciphisa ngempumelelo ukumelana nokubola kwentsimbi. Oku kuyacaca ukuba ukubola kwenzeka kwindawo echaphazelekileyo kubushushu (HAZ) yee-welds zentsimbi engagqwali. Enye into eqwalaselwayo ngentsimbi engagqwali ye-grade L kukuba zinamandla aphantsi okutyhafa kumaqondo obushushu aphezulu okusebenza kunee-grades zentsimbi engagqwali ethe tye.
Ekubeni i-304 iluhlobo lwentsimbi engagqwaliyo oluyi-austenitic, intsimbi ye-weld ehambelanayo iya kuba nenxalenye enkulu ye-austenite. Nangona kunjalo, i-electrode ngokwayo iya kuba ne-ferrite stabilizer, efana ne-molybdenum, ukukhuthaza ukwakheka kwe-ferrite kwintsimbi ye-weld. Abavelisi badla ngokudwelisa uluhlu oluqhelekileyo lobungakanani be-ferrite kwintsimbi ye-weld. Njengoko bekutshiwo ngaphambili, ikhabhoni sisixhobo esinamandla se-austenitic stabilizer kwaye ngenxa yezi zizathu kubalulekile ukuthintela ukongezwa kwayo kwintsimbi ye-weld.
Amanani eFerrite athathwe kwitshathi yeScheffler kunye netshathi yeWRC-1992, esebenzisa iifomula ezilinganayo ze-nickel kunye ne-chromium ukubala ixabiso eliza kuthi xa lidwetshwe kwitshathi linike inani eliqhelekileyo. Inani leFerrite eliphakathi kwe-0 kunye ne-7 lihambelana nepesenti yevolumu yesakhiwo sekristale yeFerritic ekhoyo kwisinyithi se-weld, nangona kunjalo, kwiipesenti eziphezulu, inani leFerrite landa ngokukhawuleza. Khumbula ukuba iFerrite kwi-SS ayifani neFerrite yentsimbi yekhabhoni, kodwa yiphase ebizwa ngokuba yiDelta Ferrite. Intsimbi engagqwaliyo yaseAustenitic ayitshintshi iphase enxulunyaniswa neenkqubo zobushushu obuphezulu ezifana nonyango lobushushu.
Ukwakheka kweFerrite kuyathandeka kuba ithambile kakhulu kune-austenite, kodwa kufuneka ilawulwe. Umxholo weFerrite ophantsi unokubonelela nge-welds ngokumelana nokugqwala okuhle kwezinye iinkqubo, kodwa zinobunzima obukhulu bokuqhekeka ngexesha lokuwelda. Ukusetyenziswa ngokubanzi, inani leeFerrite kufuneka libe phakathi kwe-5 ne-10, kodwa ezinye iinkqubo zinokufuna amaxabiso aphantsi okanye aphezulu. IiFerrite zinokujongwa lula kwindawo yokusebenza ngesalathisi seFerrite.
Ekubeni uthe uneengxaki zokuqhekeka kunye neeferrite eziphantsi, kufuneka ujonge i-filler metal yakho kwaye uqinisekise ukuba ivelisa iiferrite ezaneleyo - malunga ne-8 kufuneka zenze icebo. Kwakhona, ukuba usebenzisa i-flux-cored arc welding (FCAW), ezi filler metals zihlala zisebenzisa i-shield gas ye-100% carbon dioxide okanye umxube we-75% argon kunye ne-25% CO2, enokubangela ukuba i-weld metal ifunxe ikhabhoni. Ungatshintshela kwinkqubo ye-metal arc welding (GMAW) kwaye usebenzise umxube we-98% argon/2% oxygen ukunciphisa amathuba okuba kubekho ii-carbon deposits.
Xa kudityaniswa intsimbi engagqwaliyo kwintsimbi yekhabhoni, kufuneka kusetyenziswe izinto zokugcwalisa i-E309L. Le ntsimbi yokugcwalisa isetyenziselwa ngokukodwa ukudityaniswa kwentsimbi eyahlukileyo, okwenza inani elithile le-ferrite emva kokuba intsimbi yekhabhoni inyibilikisiwe kwi-weld. Ngenxa yokuba intsimbi yekhabhoni ifunxa ikhabhoni ethile, iziqinisi ze-ferrite zongezwa kwintsimbi yokugcwalisa ukuze kuthintelwe ukuthambekela kwekhabhoni ekwenzeni i-austenite. Oku kuya kunceda ukuthintela ukuqhekeka kobushushu ngexesha lokudityaniswa.
Ukuqukumbela, ukuba ufuna ukulungisa iintanda ezishushu kwii-welds zentsimbi engagqwaliyo ze-austenitic, jonga ukuba i-ferrite filler metal yanele na kwaye ulandele indlela elungileyo yokuhlanganisa. Gcina ubushushu bungaphantsi kwama-50 kJ/in, gcina amaqondo obushushu aphakathi ukuya kwaphantsi phakathi kwee-pass, kwaye uqinisekise ukuba iindawo zokufaka i-solder zicocekile ngaphambi kokuba zifakwe i-solder. Sebenzisa i-gauge efanelekileyo ukujonga ubungakanani be-ferrite kwi-weld, ujolise kwi-5-10.
I-WELDER, eyayisakuba yi-Practical Welding Today, imele abantu bokwenene abenza iimveliso esizisebenzisayo nesisebenza ngazo yonke imihla. Le magazini ibikhonza uluntu oludibanisa iintsimbi eMntla Melika kangangeminyaka engaphezu kwama-20.
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