TL; DR:Yog tias koj lub phaj hnyav welds tawg lub lis piam tom qab xa khoom, lub hauv paus ua rau yuav luag txhua zaus hydrogen daig hauv HAZ - tsis yog cov welders phem. Kev txhim kho pib nrog kev suav cov hlau Carbon Equivalent Value (CEV), tom qab ntawd ua kom preheat tiag tiag (150℃yam tsawg kawg nkaus, txheeb xyuas los ntawm kev sib cuag pyrometer, nrog rau lub sijhawm ntub dej) ntawm txhua qhov sib koom ua ke qhov twg CEV> 0.45 thiab thickness> 25mm. Ntawm no yog metallurgy, lej, thiab rau 6 lo lus nug uas cais cov khw muag khoom raws li daim ntawv- ua raws.
Cov cuab yeej hnyav OEM hauv cheeb tsam Western Australia tau hu rau peb thaum ntxov 2026 nrog ib qho teeb meem uas lawv tsis tuaj yeem pin. Rau ntawm plaub caug boom- caj npab brackets tau tsim cov kab nrib pleb hauv plaub lub lis piam tom qab tuaj txog - thiab cov kab nrib pleb ua raws li tus ntiv taw ntawm cov fillet welds yuav luag raws nraim. Cov welds tau dhau qhov kev kuaj pom ntawm peb cov neeg muag khoom lub khw. Lawv tau dhau qhov ntsuas qhov ntsuas. Lawv tau dhau los ua qhov yooj yim UT scan.
Qhov lawv tsis tau hla yog 60℃thaum hmo ntuj kub poob ntawm txoj kev thauj los ntawm Fremantle mus rau Pilbara kuv qhov chaw.
Ntawm no yog metallurgy feem ntau cov neeg yuav khoom tsis pom ntawm WPS - thiab vim li cas nws thiaj txiav txim siab seb koj lub phaj vuam qhov project ua rau nws mus txog ib hlis.
Cold Cracking tsis yog teeb meem Welder. Nws yog qhov teeb meem Hydrogen.
Hnyav phaj vuam - txhua yam dhau li ntawm 12 hli - qhia peb qhov kev ntxhov siab uas qhov vuam yuav tsum tau tawg ua ntej nws ruaj khov: thermal shrinkage raws li lub pas dej weld txias, txwv tsis pub los ntawm ib puag ncig niam txiv hlau, thiabdiffusible hydrogenabsorbed rau hauv lub weld thaum lub sij hawm arc tawm tsam.
Hydrogen nkag mus rau hauv lub vuam los ntawm ya raws hauv cov flux, av noo nyob rau hauv lub shielding gas, los yog nto kab mob ntawm lub phaj ntug. Nyob rau hauv chav tsev kub nws nkag mus rau hauv lub hardened martensite microstructure ntawm tshav kub- cuam tshuam cheeb tsam (HAZ). Thaum lub qhov txias txias los ntawm 100-200℃qhov rais - raws nraim lub band ib Pilbara thaum sawv ntxov hits - cov cuab yeej hydrogen presses lub brittle martensite kom txog rau thaum ib tug tawg pib. Qee zaum teev tom qab. Qee zaum hnub. Qee lub sij hawm lub lim tiam.
Qhov kev ncua ntawd yog vim li cas qhov tawg tshwmtom qabqhov tau txais kev kuaj xyuas dhau. Kev tshawb fawb ntawm siab - tensile hnyav phaj multipass welds lees paub tias transverse HAZ tawg tuaj yeem pib teev, hnub, lossis txawm lub lis piam tom qab vuam - tsav los ntawm tib lub hydrogen- thiab- kev txwv tsis pub siv, thiab ncaj qha cuam tshuam rau cov pa roj carbon sib npaug siab tshaj 0.45–0.50%.
CEV Formula txiav txim siab seb koj puas nyob hauv Danger Zone
Ib tus lej uas kwv yees seb cov hlau puas yuav hydrogen - tawg nyob rau hauv kev txwv yog qhovCarbon Equivalent Value (CEV)- xam raws li IIW (International Institute of Welding) formula, as referenced in AWS D1.1:
CEV=C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15
Rau cov qib steel peb khiav feem ntau nyob rau hauv nruab nrab phaj thiab hnyav phaj vuam:
•Q235 / ASTM A36- CEV feem ntau 0.30–0.38 → preheat yeem nyob rau hauv qis qis
•Q355 / ASTM A572 Gr.50- CEV feem ntau 0.42–0.48 → preheat yuav tsum tau ntawm t > 20mm
•Q690 / ASTM A514 Cov Lus Qhia- CEV feem ntau 0.55–0.65 → preheat yuav tsum tau nyob rau hauv tej thickness, nrog nruj hydrogen tswj
Thaum CEV hla0.45thiab ua ke thickness nce saum toj no25 hli, ob qho tib si AS/NZS 1554.1 thiab AWS D1.1 hu rau preheat - thiab tsis yog "sov lub phaj nrog rosebud rau ob feeb" yam. Ib tug tiag tiag preheat hits150℃yam tsawg kawg nkausntawm qhov sib koom ua ke, tuav los ntawm tag nrho thawj - hla welding, nrog interpass capped ntawm230 degreekom tsis txhob grain coarsening hauv HAZ.
Cov lej yog nyob rau hauv txhua tus qauv. Kev qhuab ntuas los tswj nws txhua hnub yog qhov uas cov neeg xa khoom feem ntau hla.
Dab tsi tiag Preheat zoo li ntawm lub khw hauv pem teb
Muaj qhov sib txawv ntawm daim ntawv nplaum ntawm WPS uas hais tias "Preheat 150 degree" thiab hauv pem teb uas ua tau tiag tiag. Nyob rau hauv peb ISO 3834-2 welding cell, preheat yog txheeb xyuas ntawm rau qhov chaw kuaj xyuas:
•Nto pyrometer, tsis ambient cua.Lub clamped thermocouple los yog hu rau pyrometer nyeem tau tsawg kawg yog 25 hli los ntawm qhov sib koom ua ke ntawm ob sab - lossis 1.5 × phaj thickness yog tias ntau dua - yog li cov niam txiv hlau tau txheeb xyuas raws li cov dej ntws los ntawm, tsis yog daim tawv nqaij xwb - sov. Ib rab phom infrared taw rau ntawm huab cua khoob nyeem chav, tsis yog hlau.
•Soak band ua ntej ntaus.Lub phaj zaum ntawm qhov kub kom tsawg li 2 feeb rau 25 hli tuab. Lub phaj 50mm tau txais plaub-feeb feeb ua ntej thawj qhov kev tawm tsam. Hla lub soak yog feem ntau ua rau "Kuv preheated tab sis nws tseem tawg."
•Hydrogen{0}} tswj cov khoom siv.Rau CEV > 0.45 qib peb khiav theem pib-coated qis- hydrogen electrodes tuav hauv pas nrig qhov cub ntawm 120-150℃txij li lub sijhawm qhib lub kaus poom. Moisture absorbed thaum lub sij hawm ambient cia yog raws nraim li hydrogen qhov chaw tus qauv kwv yees.
•Tack welds tsis raug zam.Txhua tack nkag mus rau hauv cov hlau preheated - tib qhov kub thiab txias, tib yam kev qhuab qhia. Qhov txias tack yog qhov pib tawg uas tsis muaj ntau npaum li cas ntawm ncej-weld preheat tuaj yeem thim rov qab.
•Vuam cuam tshuam raws tu qauv.Yog hais tias lub arc nres rau ib qho laj thawj - hloov pauv, cov khoom ua haujlwm txhaum cai, noj su noj - qhov sib koom yuav tsum tau rov ua dua - txheeb xyuas qhov kub thiab txias ua ntej dhau mus tom ntej. Ib qho kev sib koom ua ke uas zaum thaum hmo ntuj ntawm ambient tsis yog ib qho kev sib koom ua ke, txawm tias nws tau preheated nag hmo.
•Interpass qab nthab.Ib tug pyrometer thib ob saib xyuas qhov kub siab tshaj plaws ntawm kev hla. Hla lub qab nthab 230℃thiab koj ua lag luam cracking txaus ntshai rau toughness poob - txawv tsis ua hauj lwm hom, tib yam tsis lees paub batch.
Rau lo lus nug tsim nyog nug koj tus neeg muag khoom
Yog tias koj tab tom nrhiav cov phaj hnyav, lub hauv paus thav duab, lossis cov txheej txheem vuam los ntawm lub khw muag khoom hauv Suav teb, cov lus nug 6 no cais cov neeg muag khoom uas tuaj yeem qhia koj tus lej los ntawm cov uas tuaj yeem qhia koj lub logo ntawm lub vev xaib:
1. "CEV ntawm lub phaj koj yuav yog dab tsi rau txoj haujlwm no?"- Yog tias lawv tsis paub, WPS tsis raug ntsuas rau cov hlau tiag.
2. "Dab tsi yog qhov tsawg kawg nkaus preheat kub rau qhov sib koom ua ke uas tawg ntawm no?"- Lub ntsej muag dawb paug txhais tau hais tias WPS tawm ntawm tus qauv, tsis yog tawm ntawm cov khoom.
3. "Yuav ua li cas koj paub tseeb preheat rau hauv pem teb - clamped thermocouple, IR phom, los yog hla nws?"- Cov lus teb qhia rau koj seb WPS puas raug yuam los yog xav tau.
4. "Koj tswj hydrogen dab tsi rau qis-h electrodes?"- Qws qhov cub saum 120℃yog cov lus teb pom. Lwm yam yog kev xav.
5. "Qhia kuv cov ntaub ntawv batch tsis ntev los no nrog lub interpass log ntawm nws."- Lub cav tiag tiag muaj dhau-los ntawm- kis tus lej thiab ib qho pyrometer kab. A "peb tsuas yog ua nws" cov lus teb tsis muaj.
6. "Koj puas siv postheat rau siab -CEV lossis tuab- ntu cov pob qij txha - thiab koj puas tuaj yeem qhia kuv lub sijhawm- ntsuas kub?"- Rau CEV > 0.55 lossis ntu siab tshaj 50mm, postheat (250℃× 4h) yog tus qauv tiv thaiv kev ncua kev tawg. Yog hais tias lo lus teb yog "peb cia li cia nws txias maj mam," uas tsis yog postheat. Qhov ntawd yog kev cia siab.
Thawj tus neeg muag khoom uas teb tag nrho rau rau nrog tus lej tiag yog feem ntau yog tus uas nws qhov chaw tuaj txog yam tsis muaj qhov tawg.
Vim li cas qhov no txuas rau koj qhov tau txais QA
Qhov txias - teeb meem tawg ntawm Pilbara qhov chaw tsis tshwm sim ntawm peb cov neeg muag khoom lub chaw soj ntsuam. Nws tau tshwm sim ntawm OEM qhov chaw txais khoom, plaub lub lis piam tom qab, nyob rau hauv ib puag ncig txias dua txhua yam uas cov vuam tau pom hauv khw. Qhov ntawd yog qhov xwm txheej ntawm ncua sijhawm hydrogen tawg: nws ua raws li qhov kev pabcuam, thiab tsuas yog tshwm sim thaum ib puag ncig txias.
Rau OEM cov neeg yuav khoom siv cov khoom siv hlau, cov khoom siv mining weldments, lossis trailer thiab chassis brackets rau hauv Australian tej yam kev mob - ntug dej hiav txwv Western Australia, alpine Tasmania, los yog ib qho chaw uas poob qis dua 10℃thaum hmo ntuj - preheat kev qhuab qhia ntawm WPS tsis yog cov ntaub ntawv. Nws yog qhov sib txawv ntawm ib feem uas tuaj txog tag nrho thiab ib feem uas tuaj txog nrog plaub-lub lim tiam- ncua kev tawg.
Peb tau ci nws rau hauv peb cov ntaub ntawv ISO 3834 vim tias cov lej preheat yog qhov txiav txim siab seb cov ntaub ntawv puas tsim nyog sau ua ntej.
Txij li thaum siv peb cov txheej txheem preheat pov thawj tam sim no nyob rau hauv 2024, peb tau xa tuaj300+ tonnesntawm cov phaj hnyav weldments rau Australian OEMs nyob rau hauv rau -chaw saib xyuas kev qhuab qhia - nrog xoom txias- tawg rov qab mus rau hnub tim.
Tsuas yog tshawb nrhiav? Tsawg- kev sib txhuam thawj kauj ruam.SaibUa ntejhauv qab no thiab kuv mam li xa koj peb 5- nplooj ntawv qhia preheat - CEV qhov pib, lub sij hawm ntub dej, tack weld cov cai, cuam tshuam raws tu qauv, thiab cov cai tswj hydrogen rau Q355, Q690, thiab ASTM A572 Gr.50 phaj.
Khiav ib qhov project nyob?Xa koj cov duab kos rau peb rau DFM dawb thiab kev tshuaj xyuas cov hlau hlau. Peb mam li khiav koj qib, thickness, thiab sib koom geometry los ntawm CEV lej thiab qhia koj raws nraim qhov twg welds xav tau preheat, dab tsi kub, thiab dab tsi consumables - ua ntej thawj phaj hits lub rooj txiav. Engineering teb hauv 24 teev. NDA ntawm kev thov.
Hais txog tus sau:Qingdao Tianhua Yihe Hlau Fabrication yog 7,000㎡ ib leeg- lub khw hauv Qingdao khiav ISO 3834-}2 (qib tiav) vuam, AS/NZS 5131 kev ua haujlwm, AS/NZS 4680 HDG1s, thiab ua haujlwm zoo hauv AWS D1. phaj vuam, thiab ntawv hlau fabrication txhua hnub, nrog 20 xyoo ntawm cov qauv hlau OEM xa tawm mus rau Australia thiab thoob ntiaj teb kev lag luam.
