Phau ntawv arc down welding yog haum rau txoj kab uas hla tsis tsawg tshaj Φ159mm × 7mm, thiab cov khoom yog carbon steel thiab zoo tib yam uas tsis muaj alloy hlau.
Nta: kev ua haujlwm siab ntau lawm, zoo vuam zoo, piv nrog phau ntawv nce qib vuam, kev ua haujlwm tau zoo tuaj yeem txhim kho ntau dua 2 zaug. Piv txwv li, cellulose-hom downward vuam electrodes yuav tsum tau siv raws li electrodes rau roj thiab dej pipelines, uas yog dav siv nyob rau hauv cov roj pipeline tej yaam num, xws li Beijing-Tianjin aviation roj, Hainan ntev-kev thauj mus los thiab lwm yam dej num.
Ib. Feature ntawm phau ntawv down welding ua haujlwm
Sau ua tsib lo lus: "loj, ceev, nyias, ntau, ruaj":
Lub vuam tam sim no loj; qhov vuam ceev yog ceev; lub vuam deposit hlau yog nyias; welding txheej yog ntau; lub arc txav yuav tsum ruaj khov.
Piv txwv li, thaum lub workpiece ntawm Φ377mm × 8mm yog welded nrog ib tug loj zawj, ntxiv rau thawj txheej ntawm lub hauv paus welding thiab thib ob txheej ntawm thermal vuam, txhua txheej yog ntim nrog kab welding thiab cap vuam. Cov qauv zawj yog qhia hauv daim duab 1.
Qhov thib ob, cov txheej txheem vuam
1. Khoom siv: haum rau DC, silicon rectifier, inverter vuam tshuab (nrog tshuab tam sim no).
2. Cov khoom siv vuam: Cov khoom siv hauv paus yog carbon steel (Q195, Q215, Q235, thiab lwm yam), zoo tib yam low-alloy steel (× 52, × 60, thiab lwm yam), nrog cov yeeb nkab diameters ntawm 168.3mm, 377mm, 813mm, thiab 1016mm, ua.
Cov khoom siv vuam tuaj yeem xaiv Austria "Bole" electrode E6010 Φ3.2mm, Φ4.0mm.
3. Kev npaj ua ntej welding: Ua ntej vuam, tshem tawm cov dej noo, roj, thiab slag tom qab roj txiav ntawm 15 ~ 25mm ntawm sab hauv thiab sab nraud ntawm qhov zawj ntawm cov yeeb nkab kom nthuav tawm cov hlau nplaum (kom tsis txhob muaj qhov tsis xws luag xws li pores thaum lub vuam. txheej txheem).
4. Cov cuab yeej thiab kev tiv thaiv kev ua haujlwm: sib tsoo tshuab, sib tsoo lub log, steel hlau log, tsom iav, plua plav hau, lub tes tsho ntev tawv, tes rauj.
Peb, cov khub
Thaum lub kaum sab xis ntawm txoj kab nqes yuav tsum yog 30 degree ± 2 degree, qhov zawj tsis tuaj yeem kho rau lub qhov rooj lossis qhov chaw convex, uas yuav cuam tshuam rau qhov vuam zoo.
Cov khoom siv hauv paus: 20 # specification Φ377mm × 8mm ua piv txwv.
Plaub, tack welding
Sab hauv phab ntsa ntawm cov yeeb nkab fittings yog positioned ntawm 4 qhov chaw nrog lub gantry phaj. Tom qab lub hauv paus welding tiav lawm, qhov chaw phaj tuaj yeem raug muab tshem tawm. Qhov ntev ntawm qhov chaw vuam seam yog li 15 hli. Yog tias lub pob tw sab hauv raug xaiv, tag nrho cov hauv paus weld hlaws yuav tsum tau welded ua ntej tshem cov pob tw sab hauv; kwv yees li sib npaug thiab sib npaug. Kev faib tawm thiab kev teeb tsa ntawm qhov chaw thaiv yog pom hauv daim duab 2.
Tsib, welding txheej txheem tsis
Raws li cov xwm txheej ntawm qhov chaw tsim kho thiab cov txiaj ntsig ntawm kev ntsuam xyuas cov txheej txheem, cov kev xaiv vuam tsis raug pom nyob rau hauv cov lus txuas.
Rau, vuam
1. Hauv paus vuam
Ntawm cov plaub-txheej welds, hauv paus welding yog qhov tseem ceeb tshaj plaws. Nws yog ib qho tsim nyog los xyuas kom meej tias cov hauv paus hniav ntawm weld yog nkag mus, thiab cov hauv paus hniav yuav tsum tsis txhob melted los ntawm. Nws yog lub hauv paus rau kev vuam ntawm cov khaubncaws sab nraud povtseg ntawm welds, yog li cov hauv paus hniav vuam yog qhov nyuaj tshaj plaws.
Txoj kev ua haujlwm: pib vuam ntawm 12 teev ntawm txoj haujlwm ntawm lub vuam chaw nres nkoj (Daim duab 3), thiab ob lub vuam vuam yuav vuam nyob rau hauv ob qho kev qhia, sab laug thiab sab xis, thiab vuam pas nrig feem ntau tsis viav vias. Thaum lub qhov nrawm nrawm nrawm dhau lawm, lub arc tuaj yeem thim rov qab. Los ntawm 12: 00 mus rau 1 (11) taw tes yog tiaj vuam, los ntawm 1 (11) mus rau 4 (8) taw tes yog ntsug vuam, los ntawm 4 (8) taw tes rau 6 taw tes yog overhead vuam, inclination ntawm lub electrode yog raws li qhia hauv daim duab 3 qhia. Lub electrode yuav tsum maj mam nias ntawm lub hauv paus ntawm qhov zawj, thiab nws tsis yog qhov tsim nyog los khaws ib qho arc ntev. Ua lub kaum sab xis, tom qab ntawd pib lub arc ntawm 5 ~ 10mm saum qhov sib koom ua ke, rub nws mus rau qhov sib koom ua ke, thiab tom qab ib feem yog yaj, lub suab nkag tau hnov thiab txuas txuas ntxiv mus.
Thaum lub sij hawm tsim kho ntawm qhov chaw, los ntawm kev sib txuas ncaj nraim mus rau ntsug vuam mus rau cov nyiaj siv ua haujlwm vuam arc xaus, cov welders tuaj yeem siv cov vuam kub ceev cov pob qij txha raws li lawv qhov kev ua haujlwm zoo los txhim kho kev ua haujlwm thiab txuag sijhawm.
2. Kub vuam
Lub hom phiaj yog txhawm rau ntxiv dag zog rau hauv paus weld hlaws, thiab tib lub sijhawm ntxiv cov cua sov ntau, ua kom lub vuam ntawm qhov kub thiab txias, tiv thaiv kev tawg thiab tawg, thiab tseem tshem tawm cov seem vuam slag ntawm lub kaum sab xis ntawm cov hlaws vuam. Feem ntau, lub sijhawm vuam lub sijhawm nruab nrab ntawm cov vuam vuam thiab cov hauv paus vuam yuav tsum tsawg dua 5 feeb, thiab qhov kub ntawm qhov sib txuas yuav tsum siab tshaj 100 degree.
Txoj kev ua haujlwm: Lub vuam ceev thiab kev ua haujlwm yuav tsum ceev thiab sib koom ua ke, thiab qhov ntev arc yuav tsum khaws cia ntawm 5 ~ 8mm.
3. Filler vuam
Lub hom phiaj yog sau cov hlaws weld, tab sis tsis txhob tom ntug ntawm bevel, los tsim lub hauv paus zoo rau lub hau vuam.
Txoj kev ua haujlwm: Thaum sau cov vuam, cov electrode tuaj yeem ua viav vias sab laug thiab sab xis. Yog tias lub kaum sab xis me me, nws tuaj yeem txav mus ncaj nraim yam tsis muaj viav vias. Thaum welding mus rau 5 (7) teev, ua ib lub voj voog me me. Tsawg, qhov ntev arc yog qhov zoo dua 2 ~ 3 hli, thiab cov hlaws muab tub lim yuav tsum tau welded rau 1 ~ 1.5 hli hauv qab ntawm cov yeeb nkab.
4. Cap vuam
Lub hom phiaj yog sau cov hlaws weld, txhim kho lub zog thiab ua kom zoo nkauj ntawm vuam.
Txoj kev ua haujlwm: Thaum lub hau welding, txav lub strip downwards thiab viav vias sab laug thiab sab xis, tab sis lub viav vias yuav tsum tsis txhob loj heev, nws yog tsim nyog los nias lub npoo ntawm qhov zawj los ntawm 1 ~ 1.6 hli, thiab lub arc ntev yuav tsum luv, Feem ntau 2 ~ 3 hli, thiab vuam rau nyiaj siv ua haujlwm vuam Thaum kawg ntawm lub arc, lub arc crater yuav tsum tau sau raws li tangential kev taw qhia ntawm vuam taw tes, thiab lub arc yuav tsum tau sib npaug elongated kom tsis txhob nto pores thiab lub zos superelevation los yog undercut.
Xya, feem ntau welding defects (downward welding)
1. Cov hlaws vuam yog nqaim dhau thiab siab dhau - yog vim li cas: lub kaum sab xis ntawm lub tshuab electrode tsis raug, qhov vuam tam sim no me dhau, thiab qhov nrawm nrawm dhau.
2. Nto pores - Yog vim li cas: lub arc ceev thiab viav vias ntau dhau lawm, thiab cov electrode yog damp.
3. Slag suav nrog - yog vim li cas: kev ntxuav ntawm cov hlaws vuam tsis zoo, thiab lub kaum sab xis ntawm nws ob sab feem ntau yog vim lub hauv paus tu tam sim no me dhau.
4. Undercut - Yog vim li cas: qhov tam sim no loj heev, lub arc ua hauj lwm tsis nyob rau hauv qhov chaw, thiab downward arc rub ceev yog ceev heev.
5. Cov hauv paus hniav yog concave thiab tsis nkag mus - yog vim li cas: lub hauv paus welding tshuab tam sim no loj heev, lub spatter yog loj, thiab lub hauv paus melting dav yog loj heev. Cov electrode tsis nias rau ntawm lub hauv paus ntawm qhov zawj thiab hlawv ib txwm ua rau lub qhov molten.
Yim, xaus lus
Cov yam ntxwv ntawm kev ua haujlwm ntawm electrode arc down welding tuaj yeem ua tiav hauv 5 lo lus, uas yog "loj, ceev, nyias, ntau thiab ruaj khov".
Piv txwv li, thaum vuam Φ813mm × 2.7mm steel yeeb nkab, nyob rau hauv cov ntaub ntawv ntawm cov zawj loj, tshwj tsis yog rau thawj txheej ntawm cov hauv paus hniav vuam thiab cov txheej thib ob ntawm cov cua sov welding, lwm cov khaubncaws sab nraud povtseg tau ntim thiab npog los ntawm kab vuam.
