1. Nqe Lus Nug: Lub zog tensile (R_m) yuav tsum tau ua li cas rau Q460 lub hauv paus hlau piv rau lub zog tensile yuav tsum tau rau nws cov hlau sib txuas?
Teb: Lub hauv paus hlau thiab vuam hlau yuav tsum sib txawv. Rau Q460 puag hlau, lub zog tensile feem ntau teev raws li 550-720 MPa. Rau cov hlau weld, thaum ua raws li "kev sib tw hauv paus ntsiab lus," nws feem ntau yuav tsum muaj lub zog tensile uas tsawg kawg yog sib npaug rau qhov tsawg kawg nkaus tensile lub zog ntawm lub hauv paus hlau (piv txwv li, tsawg kawg yog 550 MPa). Txawm li cas los xij, nws feem ntau yog khaws cia qis dua qhov siab tshaj plaws (720 MPa) kom ntseeg tau tias muaj qhov dej txaus. Qee cov cai hais tias cov hlau vuam tuaj yeem ua "tsis zoo" hauv kev tawm dag zog tab sis yuav tsum yog "kev sib tw" lossis "overmatching" hauv lub zog tensile kom ntseeg tau tias kev sib koom ua ke tag nrho kev ncaj ncees nyob rau hauv tensile overload.
2. Lo lus nug: Dab tsi yog cov tshuaj muaj pes tsawg leeg txwv rau Manganese (Mn) hauv Q390 piv rau Q460, thiab vim li cas qhov sib txawv no tseem ceeb?
Teb: Manganese yog cov khoom tseem ceeb -cov tshuaj tiv thaiv. Q390 feem ntau muaj cov ntsiab lus manganese nyob ib puag ncig 1.00-1.60%. Q460, xav tau lub zog ntau dua, yuav muaj ntau dua manganese, feem ntau 1.20-1.70% lossis ntau dua. Qhov nce Mn cov ntsiab lus no yog qhov tseem ceeb rau kev nce lub zog ntawm ferrite theem. Txawm li cas los xij, qhov siab dua Mn hauv Q460 kuj ua rau nws cov hardenability thiab carbon sib npaug (Ceq), uas, raws li tau hais yav dhau los, ua rau nws muaj kev cuam tshuam rau vuam tawg. Qhov kev sib pauv no ntawm kev ua tiav lub zog siab dua thiab tswj xyuas qhov zoo weldability yog vim li cas Mn cov ntsiab lus tau ua tib zoo tswj.
3. Nqe Lus Nug: Hauv kev tsim cov high- zaus induction (HFI) welded kav los ntawm Q420, qhov zoo ntawm cov vuam seam feem ntau yog qhov tseeb tsis yog- puas tsuaj?
Teb: Tom qab HFI vuam txheej txheem, vuam seam ntawm Q420 yeeb nkab yog raug rau 100% tsis yog- kuaj kev puas tsuaj (NDT). Txoj kev siv ntau tshaj plaws yog kev kuaj hauv online ultrasonic (UT) siv lub rotating lossis phased-array UT system. Qhov no system scans tag nrho cov weld seam rau tsis muaj fusion, tawg, los yog lwm yam sab hauv flaws. Tsis tas li ntawd, lub weld yuav raug tshuaj xyuas siv eddy tam sim no los yog flux to. Cov chaw tsim khoom kuj tseem yuav tsum ua cov kev ntsuam xyuas kev puas tsuaj ib ntus, xws li kev ntsuam xyuas flattening thiab transverse tensile tests, ntawm cov qauv txiav los ntawm cov yeeb nkab kawg kom lees paub qhov kev ncaj ncees ntawm weld.
4. Nqe Lus Nug: Vim li cas nws feem ntau pom zoo kom siv cov vuam qis qis rau Q420 thiab Q460 piv rau qis dua - lub zog steel?
Teb: Txawm hais tias nws yuav zoo li counterintuitive, siv cov hluav taws xob qis dua rau cov qib siab -lub zog steels pab txo cov qoob loo loj hlob hauv tshav kub- thaj chaw cuam tshuam (HAZ). Ib qho hluav taws xob loj hauv hluav taws xob tso tawm ntau lub zog, ua rau HAZ nyob ntawm qhov kub thiab txias rau lub sijhawm ntev, uas tso cai rau cov nplej austenite loj hlob ntau dhau. Thaum txias, cov nplej loj no hloov mus ua ntxhib, brittle microstructures. Qhov qis dua, tswj cov cua sov, ua ke nrog preheating los tiv thaiv kev tawg, kom ntseeg tau tias HAZ muaj lub sijhawm luv dua ntawm qhov kub siab tshaj plaws, ua rau cov nplej loj dua thiab tawv dua, tawg ntau dua - tiv thaiv kev sib koom ua ke.
5. Nqe Lus Nug: Cov kev ntsuam xyuas tshwj xeeb twg yog qhov yuav tsum tau ua los ntawm GB / T 13793 tus qauv kom tsim nyog rau ntau lawm Q460 welded kav?
Teb: Yuav kom tsim nyog ntau Q460 welded kav raws li GB / T 13793, ib lub chaw tsim khoom yuav tsum ua ntau yam kev ntsuam xyuas ntawm cov qauv coj los ntawm cov yeeb nkab. Cov no suav nrog kev sim transverse tensile ntawm tus qauv uas muaj cov vuam kom ntseeg tau tias qhov sib koom ua ke lub zog ua tau raws li qhov tsawg kawg nkaus; ib qho kev ntsuas khoov (lub ntsej muag thiab hauv paus) txhawm rau ntsuas qhov vuam ductility; thiab ib qho kev ntsuam xyuas flattening, qhov twg ib feem ntawm tag nrho cov yeeb nkab yog crushed tiaj tus los xyuas qhov kev ncaj ncees thiab ductility. Tsis tas li ntawd, rau qee qib thiab cov ntawv thov, cov kev ntsuam xyuas cuam tshuam (xws li Charpy V-notch ntawm qhov ntsuas kub) yog xav tau ntawm lub hauv paus hlau thiab tej zaum yuav muaj cov hlau weld thiab HAZ.
