Hauv kev sib sau ua ke, thaj chaw xws li roj av, tshuaj lom neeg, nkoj tsim, thiab cov hlab ntsha siab pom kev vuam zoo li lub cev pob txha ntawm cov qauv. Yog tias cov pob txha ruaj khov, cov cuab yeej siv tau ruaj khov thiab tiv taus qhov mob.
Tab sis - koj puas tau ntsib qhov xwm txheej no? Koj xav tias koj cov txheej txheem vuam yog qhov tsis muaj qhov tsis zoo, tab sis cov weld seams tsis tu ncua tsis muaj zog txaus -txawm yog ua raws li cov iav tawg, tawg ntawm kev siv zog me ntsis, lossis, txawm tias qhov kev ntxhov siab ntau dua, ua rau muaj kev sib txuam ntawm cov qhov hws me me, ua rau koj cov khoom seem rau skyrocket.
Yog tias koj lub rooj cob qhia tsis tu ncua los ntawm cov teeb meem ntxhov siab no, qhov teeb meem yuav nyob nrog peb cov "killers" gaseous uas tsis pom ntawm qhov muag liab qab, tsis tau ntse dua li cov hniav: Nitrogen, Hydrogen, thiab Oxygen.
Niaj hnub no, cia peb mus tob tob rau hauv qhov "vim" no trio tuaj yeem ua li cas, thiab saib raws nraim li cas lawv koom nrog ua kom puas cov txiv hmab txiv ntoo ntawm koj txoj haujlwm nyuaj.
I. Nitrogen: Ua Kev Tsis Ncaj Ncees ntawm Qhov Nto, Txawm li cas los xij "Hardest" Qab ntawm Scenes
Ua ntej mus rau theem yog Nitrogen. Ntau tus neeg pom tias nitrogen yog qhov tsis muaj kev phom sij, tsis muaj pa phem - tom qab tag nrho, nws nyob txhua qhov chaw hauv huab cua puag ncig peb. Txawm li cas los xij, nyob rau hauv qhov khaus crucible ntawm cov txheej txheem vuam, nws hloov mus ua ib qho yeeb ncuab phem heev.
Nws zais qhov twg?
Nitrogen nyob hauv huab cua puag ncig peb. Tsis txhob xav tias koj qhov kev txawj ntse arc vuam kev txawj ntse tuaj yeem tiv thaiv huab cua los ntawm kev nkag mus rau thaj chaw vuam. Cov kev txheeb cais yog sobering: thaum lub sij hawm phau ntawv arc vuam, cov ntsiab lus nitrogen nyob rau hauv lub deposited weld hlau tuaj yeem ncav cuag li 0.025%. Thaum 0.025% tej zaum yuav zoo li ib daim duab minuscule-tsuas yog 2.5 feem ntawm kaum txhiab- qhov teeb meem nws ua rau yog dab tsi tab sis me me.
💥 Dab tsi yog qhov tshwm sim?
Ntau tus kws kho mob pom tau hais tias qhov sib ntxiv ntawm nitrogen ua tau txhawb lub zog tensile ntawm weld seam, ua rau lawv zoo siab heev rau qhov tshwm sim. Qhov tseeb, txawm li cas los xij, qhov no yog qhov ntxiab loj heev!
Txawm hais tias nitrogen yuav ua rau cov khoom "nyuaj," nws ua li ntawd los ntawm kev quab yuam nws "nkig." Txhawm rau siv qhov piv txwv: xav txog tias koj yog Tai Chi tus kws kho mob -supple, nrog cov ligaments hloov tau thiab cov pob txha zoo. Nitrogen los nrog thiab hais kom tig koj mus rau hauv "txhim thaiv steel"- nyuaj thiab tsis muaj zog ntawm qhov chaw, tab sis nws yooj yim rau tawg ntawm qhov cuam tshuam me ntsis, tag nrho tsis muaj kev hloov pauv thiab kev poob siab.
Tsis tas li ntawd, nitrogen yog ib qho ntawm cov thawj culprits tom qab tsim ntawm porosity (gas npuas) nyob rau hauv lub weld. Txhawm rau tiv thaiv nws, ntxiv dag zog rau koj cov kev tiv thaiv roj yuav tsum yog koj qhov tseem ceeb tshaj plaws. Xyuas kom meej tias cov roj thaiv thaiv txheej yog tuab txaus thiab ruaj khov kom tsis txhob muaj huab cua nyob ib puag ncig los ntawm kev cuam tshuam thiab ua rau muaj paug.
Summary and Analysis of Yim Loj Defects hauv Vuam|Weld Seams
II. Hydrogen: Tus "Infiltrator" ntawm Vuam Ntiaj Teb-Tus Tswv Qhia Txog Kev Cracking
Yog hais tias nitrogen yog ib tug ncaj frontal quab yuam, ces hydrogen yog qhov nyuaj tshaj plaws - rau - zov- tawm tsam "pob zais."
Nws zais qhov twg?
Hydrogen yog ib yam tsiaj ntawm dampness; nws gravitates mus rau txhua qhov chaw ntub dej, thiab thaj chaw uas muaj roj lossis roj ua rau nws cov chaw ruaj khov.
Cov peev txheej muaj xws li noo noo nyob rau hauv electrode coatings, organic compounds tam sim no nyob rau hauv vuam khoom, xeb thiab roj residue ntawm lub workpiece nto, thiab txawm dej vapor tam sim no nyob rau hauv lub ambient huab cua thaum vuam. Thaum ua cov hlau arc vuam siv cov cellulosic electrodes, cov ntsiab lus hydrogen nyob rau hauv lub vuam seam tuaj yeem ncav cuag 70 npaug siab dua li ntawm cov hlau puag! Qhov tsuas xav txog nws yog txaus ntshai.
💥 Puas yog nws lub zog puas tsuaj?
Nws yog qhov tseeb "hma hauv yaj cov khaub ncaws." Thaum lub sij hawm vuam txheej txheem, nws plam mus rau hauv lub pas dej molten undetected thiab unnoticed.
Nws tsuas yog pib ua kev puas tsuaj thaum lub vuam seam tau txias. Tsis tsuas yog nws ua rau lub vuam nkig, tab sis - tseem ceeb dua - nws ua raws li lub zog rau tus dab tuag: * ncua kev tawg *.
Qhov feem ntau insidious nam ntawm no tshwm sim nyob rau hauv lo lus "ntev." Tam sim ntawd tom qab vuam, cov seam yuav tshwm sim flawless; koj kos npe tawm ntawm kev soj ntsuam thiab mus tsev rau hnub, txaus siab rau txoj haujlwm ua tiav. Txawm li cas los xij, thaum koj rov qab mus ua haujlwm tag kis sawv ntxov- lossis tom qab cov khoom siv tau ua haujlwm rau ib lub sijhawm -koj hnov dheev * snap*, thiab weld seam tau ntsiag to tawg. Txhawm rau tiv thaiv qhov kev hem thawj no, nco ntsoov cov kev cai ntawm peb lub tshuab hlau: ua ntej- ci electrodes ua ntej vuam, ntxuav tag nrho cov roj thiab xeb ua ntej vuam, thiab siv cov khoom siv hluav taws xob tsawg - hydrogen welding.
Kev sib piv thiab kev txheeb xyuas qhov sib txawv ntawm Tuam Tshoj National Standards (GB) thiab American Standards (ASTM) rau Hlau Tensile Test Methods|Xeem Qauv|Khoom siv hlau|Kev ntsuas tshuab|Ntev|Dav|Sina Xov Xwm
III. Oxygen: Feem ntau qhov chaw "Invisible Killer"-Ua rau tag nrho cov khoom tawg tag
Qhov kawg ua kom nws zoo li yog oxygen. Yog hais tias hydrogen yog tus yam ntxwv ntawm nws "insidiousness," ces oxygen yog txhais los ntawm nws "aggressiveness"; nws muaj qhov dav tshaj plaws ntawm toxicity thiab yog qhov nthuav dav tshaj plaws ntawm peb lub ntsiab lus.
Nws zais qhov twg?
Oxygen muaj nyob rau hauv cov huab cua puag ncig; oxides yog embedded nyob rau hauv electrode coatings; thiab oxide nplai coats nto ntawm vuam hlau. Hauv luv luv, ntawm peb lub ntsiab lus no, cov pa oxygen yog qhov tsawg tshaj plaws "tus neeg noj zaub mov noj" - nws yog ib qho uas plam mus rau thaj tsam weld nrog qhov yooj yim tshaj plaws. 💥 Nws qhov kev puas tsuaj yog txhua yam - suav nrog.
Nitrogen tsuas yog ua rau cov khoom me ntsis nkig; hydrogen ua rau nws tawg. Oxygen, txawm li cas los xij- yog ib zaj dab neeg sib txawv; Nws ua rau muaj kev puas tsuaj mus rau qib molecular. Nws txo qis zog, txo hardness, thiab ua rau tag nrho lub cev qhuav dej nyob rau hauv ductility thiab toughness -txawm ua rau "kub brittleness" thiab "txias brittleness."
Tsis tas li ntawd, nws yog tus thawj culprit tom qab porosity tsim (xws li CO₂ pores). Tej zaum koj yuav siv cov hnub nyoog zoo- kho koj qhov ntsuas, tab sis yog tias cov pa oxygen tseem siab me ntsis, tag nrho koj cov kev siv zog yav dhau los mus rau hauv qhov dej. Txhawm rau khaws cov pa oxygen hauv kev kuaj xyuas, koj yuav tsum xaiv cov khoom siv zoo - vuam siv tau zoo thiab siv zog ntau rau hauv koj qhov kev teeb tsa roj teeb. Piv txwv li, nyob rau hauv tej yam kev siv vuam, ntshiab argon ib leeg tsis txaus; koj yeej yuav tsum tau qhia me me ntawm cov pa oxidizing. Qhov no tsis yog "ua neej txaus ntshai" xwb; es, nws siv cov tshuaj tiv thaiv kom sib npaug ntawm lub pas dej ua ke, yog li * txo * qhov kev pheej hmoo ntawm qhov tsis xws luag.
Tsis txhob cia lub dag zog ntxiv los cuam tshuam koj; koj yuav tsum tuav lub "peb kab hauv qab" ntawm vuam.
Ntau tus neeg tuaj tshiab rau kev lag luam feem ntau xav tias thaum lub vuam tsis raug teeb tsa kom raug, txhua yam yog kev caij nkoj. Lawv xav tias tom qab kev sib tsoo ceev kom ua rau lub ntsej muag gleam, leej twg tuaj yeem qhia tau yog tias muaj qhov tsis zoo sab hauv?
Tab sis koj puas tau tso tseg los xav txog qhov no:
Ib thaj ntawm cov roj seem uas koj saib niaj hnub no tuaj yeem dhau los ua qhov tawg ntawm cov kav dej tag kis;
Ib qho slag- cov kauj ruam tshem tawm koj hla tag kis tuaj yeem ua rau muaj kev sib tsoo ntawm lub Hoobkas hnub tom qab;
Cov txheej txheem txheej txheem koj tsis quav ntsej hnub tom qab tag kis tuaj yeem dhau los ua qhov tsis txaus ntseeg ntawm koj txoj haujlwm tshaj lij hnub tom qab * ntawd *.
Hauv kev tsim khoom siab heev-xws li roj thiab roj, tshuaj lom neeg, kev tsim nkoj, thiab lub zog nuclear-"tsis pom" tsis sib npaug rau "tsis yog-muaj." Vuam yog ib qho "txoj kev ntawm lub siab"; lub luag hauj lwm tsis yog ib qho plaque dai rau ntawm phab ntsa xwb - nws yog etched rau hauv txhua txhua weld seam.
