Q235NH Corten Steel thiab cov pa roj carbon zoo tib yam Q235 qhia tib lub zog qib qib (235MPa yield zog), tab sis lawv cov weldability txawv me ntsis -tsav los ntawm Q235NH ntxiv los tiv thaiv-corrosion ntsiab. Rau cov fabricators thiab welders, kev nkag siab txog qhov sib txawv no yog qhov tseem ceeb kom tsis txhob muaj qhov tsis xws luag, ua kom muaj kev sib koom tes zoo, thiab txo qis kev ua haujlwm. Raws nraim li cas lawv weldability piv? Raws li kev xyaum vuam thiab kev txheeb xyuas cov khoom muaj pes tsawg leeg, cov ntsiab lus tseem ceeb yog qhov tseeb:Ob lub steels muaj qhov zoo weldability, tab sis Q235NH yuav tsum tau nruj me ntsis vuam txwv tsis pub brittleness thiab corrosion tsis muaj zog cov ntsiab lus, thaum Q235 yog ntau zam txim rau kev siv vuam dav hlau.. Hauv qab no yog ib qho yooj yim, kev txiav txim siab tawg.
Qhov tseem ceeb Weldability sib piv: Core sib txawv
Weldability yog ntsuas los ntawm arc stability, weld joint toughness, crack risk, thiab post-weld corrosion resistance- ntawm no yog yuav ua li cas ob steels sib sau ua ke hauv kev ua haujlwm:
Arc Stability: Ob leeg ua tau zoo-Q235NH's trace Cu/Cr cov ntsiab lus muaj kev cuam tshuam tsawg kawg nkaus ntawm arc stability, txuam Q235 qhov yooj yim ntawm arc tawm tsam thiab tu thaum lub sij hawm SMAW, GMAW, los yog FCAW txheej txheem.
Weld Joint Toughness: Q235NH's weld pob qij txha yog me ntsis nruj dua Q235's yog tias tsis kho. Nws cov ntsiab lus Cr/P tuaj yeem ua rau cov cua sov me ntsis- cuam tshuam thaj chaw (HAZ), thaum Q235 qhov ntshiab qis- cov pa roj carbon muaj pes tsawg leeg ua kom cov pob qij txha zoo dua, ntau dua ductile weld pob qij txha.
Crack Risk: Q235NH has a slightly higher cold crack risk than Q235, especially for thick plates. Its alloy elements increase HAZ hardness, making preheating more critical for plates >16 hli.
Ncej - Weld Corrosion Resistance: Qhov no yog qhov sib txawv loj tshaj plaws -Q235NH cov vuam pob qij txha xav tau kev kho mob kom haum rau lub hauv paus hlau qhov kev tiv thaiv corrosion, thaum Q235 cov welds yuav tsum tsis muaj kev tiv thaiv tshwj xeeb corrosion (dhau txheej txheem txheej).
Vim li cas qhov txawv? Ua rau Core
Qhov sib txawv me ntsis weldability stems tag nrho los ntawm Q235NH ntxiv los tiv thaiv -corrosion ntsiab (Cu, Cr, P) - cov ntsiab lus uas txhim kho nws cov huab cua tsis kam tab sis hloov me ntsis vuam tus cwj pwm:
Q235 yog cov ntshiab qis- carbon hlau (C Tsawg dua lossis sib npaug li 0.22%), tsis muaj cov ntsiab lus alloy ntxiv- nws cov ntsiab lus yooj yim ua rau nws zam txim ntau, txawm tias muaj qhov sib txawv me me (xws li, cov khoom siv hluav taws xob ntau dhau).
Q235NH muaj Cu (0.20-0.50%), Cr (0.30-1.20%), thiab P (0.07-0.15%) los ua ib qho kev tiv thaiv patina. Cov ntsiab lus no, tshwj xeeb tshaj yog Cr thiab P, tuaj yeem ua rau HAZ hardness thiab txo cov ductility yog tias vuam cov khoom siv hluav taws xob siab dhau los yog txias ceev heev.
Tswv yim Vuam tswv yim: Kho kom haum rau qhov sib txawv
Qhov sib txawv me me, tab sis kho cov haujlwm rau Q235NH ua kom pom kev sib koom ua ke zoo thiab corrosion kuj:
rau Q235NH: - Preheating: Mandatory for plates >16 hli (80-120 degree) kom txo tau qhov mob khaub thuas tawg; xaiv tau rau nyias daim hlau (tsawg dua los yog sib npaug li 16 hli) nyob rau hauv ib puag ncig sov. - Thaum tshav kub kub input: Tswj ntawm 15-25kJ/cm- zam dhau tshav kub (uas coarsens nplej) los yog tsis txaus cua sov (uas ua rau tsis tiav fusion). - Tom qab-Weld Treatment: maj mam muab tshem tawm seams cia cov pob qij txha ib txwm oxidize los ua ib qho kev tiv thaiv patina (tsis txhob txheej ntxov ntxov).
rau q235: - Preheating: Tsis tshua xav tau, txawm tias cov phaj siab txog 20mm (tsuas yog yuav tsum tau nyob rau hauv qhov chaw txias Tsawg dua lossis sib npaug li 0 degree). - Cov Khoom Siv Kub Kub: Kev zam txim ntau dua (15-30kJ/cm)- qhov sib txawv me me yuav tsis ua rau muaj qhov tsis xws luag-{6} Kev kho mob tsuas yog:{6} tsis muaj kev kho tshwj xeeb rau corrosion kuj.
Common Welding Defects: Sib Piv & Tiv Thaiv
Txhua lub hlau yog qhov tshwj xeeb vuam tsis xws luag, khi rau lawv qhov sib txawv ntawm qhov sib txawv:
qw 235n: Yooj yim rau HAZ brittleness thiab txias tawg yog hais tias preheating yog hla. Tiv thaiv los ntawm kev tswj tus nqi cua txias (tsis txhob ua cua txias sai rau cov phaj tuab) thiab siv cov khoom siv hluav taws xob tsawg- hydrogen.
Q235: Yooj yim rau porosity yog tias vuam qhov chaw qias neeg (roj, xeb), tab sis tsis tshua muaj qhov tshwm sim txias. Tiv thaiv los ntawm kev ntxuav qhov chaw ua ntej welding thiab tuav ruaj khov arc voltage.
Hauv cov ntsiab lus, Q235NH thiab Q235 ob leeg muaj kev sib txuas zoo rau kev tsim vaj tsev engineering thiab kev tsim khoom dav dav. Qhov sib txawv tseem ceeb yog tias Q235NH yuav tsum tau nruj me ntsis preheating thiab cua sov input tswj kom tsis txhob brittleness, ntxiv rau post-weld mloog mus corrosion kuj. Q235, los ntawm qhov sib txawv, muaj kev zam txim ntau dua rau kev siv vuam niaj hnub. Los ntawm kev kho qhov tsis sib xws kom haum rau txhua tus yam ntxwv ntawm cov hlau, cov welders tuaj yeem ua kom cov pob qij txha muaj zog thiab ruaj khov raws li lawv daim ntawv thov.
