TIG vuam feem ntau siv tungsten electrodes thiab cov roj inert (feem ntau yog argon thiab helium) los ua ib qho arc nrog lub workpiece. Ib qho electrode zoo yog qhov tseem ceeb rau kev tsim cov khoom siv hluav taws xob zoo ib yam lossis raug thiab tseem muaj kev cuam tshuam zoo rau arc stability, lub sijhawm ua haujlwm tsis tu ncua thiab vuam zoo. Nws cov kev xav tau tshwj xeeb ua haujlwm yog raws li hauv qab no:
1. Zoo heev kub ua hauj. Cov electrode yuav tsis yaj thiab hlawv thaum vuam. Txwv tsis pub, tsis tsuas yog lub electrode nws tus kheej yuav tau noj sai, tab sis kuj arc yuav drift, ua rau arc instability. Tsis tas li ntawd, thaum lub electrode melted, cov khoom siv electrode nkag mus rau hauv lub pas dej ua ke yuav ua rau cov vuam tsis zoo, tsim cov vuam tsis xws luag, thiab cuam tshuam rau qhov zoo ntawm cov vuam.
2. Muaj zog muaj peev xwm emit electrons. Kev khiav hauj lwm ntawm cov khoom siv electrode yog me me. Tshwj xeeb tshaj yog nyob rau hauv high kub, nws yuav tsum muaj ib tug muaj zog muaj peev xwm mus emit kub electrons.
3. Lub peev xwm nqa tam sim no loj. Cov electrode yuav tsum muaj hluav taws xob zoo thiab thermal conductivity thiab tuaj yeem nqa tam sim no loj yam tsis muaj cua sov.
4. Kev sib tsoo zoo. Qhov saum npoo ntawm cov electrode yuav tsum yog hauv av kom muaj qhov tseeb qhov tseeb thiab qhov kawg ntawm lub kaum sab xis, txhawm rau txhawm rau txhawm rau clamping qhov tseeb ntawm electrode thiab txhim khu kev qha conduction, tswj kev ruaj ntseg ntawm arc, thiab txhim kho cov concentration ntawm arc tshav kub.
5. Tsawg hluav taws xob. Qee yam khoom siv los txhim kho lub peev xwm ntawm electrodes kom emit electrons yog cov xov tooj cua, uas ua rau muaj kev phom sij rau tib neeg lub cev, yog li cov khoom siv hluav taws xob uas muaj hluav taws xob me me yuav tsum raug xaiv.
Tam sim no, peb lub tuam txhab tuaj yeem muab cov ntaub ntawv tungsten electrode xws li ntshiab tungsten, thorium tungsten, cerium tungsten thiab lanthanum tungsten. Ntawm lawv, ntshiab tungsten electrode muaj kev sib tsoo zoo dua thiab ua haujlwm siab dua. Nyob rau hauv DC zoo electrode vuam (tungsten yog qhov tsis zoo heev), qhov vuam tam sim no loj vim tias muaj zog thermal electron emission muaj peev xwm. Hauv DC qhov tsis zoo polarity vuam (tungsten yog qhov zoo heev), tungsten tsis tuaj yeem ua kom zoo dua ntawm cov hluav taws xob hluav taws xob kub, qhov tam sim no tsawg heev. Ac vuam, nruab nrab ntawm ob, tus nqi tam sim no tseem nyob nruab nrab.
Thib ob, thorium tungsten electrode tuaj yeem tsim los ntawm kev ntxiv 1% ~ 2 feem pua thorium oxide (ThO) rau cov tungsten ntshiab. Qhov no tuaj yeem txo qis kev khiav haujlwm ntawm cov electrode, txhim kho lub peev xwm ntawm hluav taws xob, thiab txhim kho qhov pib arc thiab arc stability ntawm lub electrode, tab sis kuj txhim kho lub peev xwm nqa tam sim no ntawm electrode thiab txuas ntxiv lub neej kev pab cuam ntawm electrode. Txawm li cas los xij, qhov me me ntawm ThO2 muaj nyob rau hauv thorium tungsten electrode yog cov xov tooj cua heev, yog li nws tsis tau siv ntau tam sim no.
Thaum kawg, txhawm rau txo cov hluav taws xob hluav taws xob ntawm cov hluav taws xob, peb siv cov hluav taws xob tsawg tsawg (Ce) es tsis txhob thorium. Kev xyaum tau ua pov thawj tias ntxiv cerium oxide (CeO) nrog ib feem ntawm kwv yees li 2 feem pua rau cov ntshiab tungsten tuaj yeem txo qhov kev khiav tawm ntawm cov electrode thiab txhim kho qhov pib arc thiab arc stability ntawm cov electrode. Tshwj xeeb tshaj yog nyob rau hauv me me tam sim no welding, lub arc tshav kub ntawm cerium tungsten electrode yog ntau concentrated, thiab cov burning tus nqi ntawm electrode yog txo. Txawm li cas los xij, nyob rau hauv lub siab tam sim no vuam, lub peev xwm los tiv thaiv overheating ntawm cerium tungsten electrode tsis zoo li tus pin tungsten electrode. Cerium tungsten electrode yog cov khoom siv hluav taws xob zoo vim tias nws tsis muaj hluav taws xob tsis muaj zog thiab muaj kev phom sij me ntsis rau tib neeg lub cev.
