Q345D belongs rau qhov qis- alloy siab- lub zog steel tsev neeg txhais los ntawm GB/T 1591, thiab tsab ntawv D yog qhov tseem ceeb ntawm kev xaiv: nws qhia txog kev cuam tshuam lub zog ntawm -20℃. Qhov kev xav tau ib leeg cais nws los ntawm cov qib kub -rolled structural qib thiab ua rau nws cov lus teb ib txwm rau cov txuas hniav, yees, cov qauv siab thiab txias- cheeb tsam fabrication qhov twg tus tsim tsis tuaj yeem lees txais chav tsev - qhov kub thiab txias-tsuas yog toughness guarantee.
Q345D Steel Yeeb Nkab yog dab tsi thiab qhov twg nws haum
Cov qib sib xyaw ua ke cov qib qis carbon nrog cov ntsiab lus manganese ntau dua thiab micro-alloying ntxiv ntawm niobium, vanadium lossis titanium. Ua ke cov no muab qhov tsawg kawg nkaus tawm lub zog ntawm 345 MPa nrog cov qoob loo loj, zoo weldability thiab ruaj khov toughness ntawm sub- xoom kub. Nws yog muab raws li welded raj thiab seamless raj nyob rau hauv round, square thiab rectangular seem.
Cov ntawv thov uas tsis tshua muaj- qhov kub ntawm cov qauv thav duab, cov kav xa hluav taws xob, cov qauv sab nrauv thiab cov chaw nres nkoj, cov khoom siv cia tank, crane booms, hnyav tsheb chassis thiab engineering dav dav hauv huab cua txias.
Chemical Composition thiab Micro-Alloying
| Khoom (%) | Kev xav tau |
|---|---|
| Carbon, max | 0.18 |
| Silicon, max | 0.50 |
| Manganese | 1.00-1.60 |
| Phosphorus, max | 0.030 |
| Sulfur, max | 0.030 |
| Nb / V / Ti | micro- ntxiv rau cov nplej ua kom zoo |
Cov pa roj carbon muaj nyob hauv qab 0.18% yog li ntawd cov cua sov- thaj tsam cuam tshuam yuav nyuaj tom qab vuam, thaum manganese nyob rau hauv 1.00-1.60% band muab lub zog thiab hardenability. Phosphorus thiab sulfur raug txwv rau 0.030% txhua qhov txhawm rau txhawm rau txhawm rau txias brittleness thiab kub luv luv. Grain-refining ntxiv yog dab tsi tso cai rau qib kom txaus siab rau -20℃cuam tshuam qhov xav tau yam tsis muaj tus nqi loj alloy.
Mechanical Properties thiab Low-Tsuas Muaj Teeb Meem
| Khoom | Tus nqi |
|---|---|
| Yield zog, min | 345 MPa rau |
| Tensile zog | 470-630 MPa |
| Elongation, min | 22 % |
| Kev cuam tshuam lub zog ntawm -20 degree, min | 34 J |
| Yield-rau-tensile ratio, max | 0.83 |
| Tsim qhov kub thiab txias | -20℃rau +350 degree |
Cov txiaj ntsig -rau-tensile ratio cap ntawm 0.83 ua kom cov khoom tseem muaj peev xwm deformation yas nyob rau hauv cia thaum overloaded, uas yog vim li cas qib tau txais rau seismic thiab dynamic qauv. Qhov twg ib txoj haujlwm hu rau qhov kev pabcuam qis dua, qhov -30℃cuam tshuam lub zog ntawm yam tsawg 27 J yog qee zaum teev raws li qhov yuav tsum tau ua ntxiv.
Q345D Versus Q345B
Toughness: Q345D yuav tsum muaj kev ntsuam xyuas ntawm -20 degree, thaum Q345B yog kuaj ntawm chav tsev kub xwb.
Kev huv huv: P thiab S qab nthab rau Q345D, 0.030% txhua, nruj dua li Q345B, uas txwv qis - kub embrittlement.
Tus me nyuam mob: Q345D yuav tsum tau muab nyob rau hauv lub normalized (N) mob; Q345B tuaj yeem muab cov khoom kub dov.
Structure: normalizing ua ib tug ntau yam ferrite-pearlite qauv nrog qis residual kev nyuaj siab thiab zoo cuam tshuam toughness.
Micro-alloying: Q345D feem ntau yog txhob txwm tshaj tawm niobium thiab vanadium ntxiv uas Q345B tsis xav tau.
Normalized xa, kho cua sov thiab vuam
Q345D yeeb nkab yuav tsum tawm hauv lub zeb nyob rau hauv lub normalized mob. Normalizing feem ntau txhais tau tias austenitising ntawm 880-920℃tom qab cua txias, nrog rau lub sij hawm soaking xam los ntawm phab ntsa thickness ntawm li 1.5 feeb ib millimeter. Phab ntsa tuab dua 40 hli xav tau ntev dua kom cov tub ntxhais ncav cuag qhov kub thiab txias thiab cov qauv tsis sib txawv los ntawm ntu. Piv nrog rau qhov kub-kuav los tiag, normalizing markedly txhim kho tej yam toughness thiab relieves dov kev nyuaj siab, thiab cov ntaub ntawv kho cua sov ua ke nrog cov cuab yeej cuab tam cov ntaub ntawv ntsuam xyuas yog muab nrog cov khoom.
Qib yog nkag welded. Tsawg-hydrogen consumables yog siv rau shielded hlau arc vuam, thiab roj hlau arc, flux-cored arc thiab submerged arc txheej txheem yog txhua yam tsim nyog rau kev ua hauj lwm ntau lawm. Preheat feem ntau tsis tsim nyog hauv qab 25 hli phab ntsa thickness ntawm nruab nrab ambient kub tab sis yuav tsum tau rau cov tuab seem, siab ceev los yog tsis tshua muaj ambient kub, thiab ib tug me me interpass txwv tiv thaiv tshav kub- cuam tshuam cheeb tsam toughness. Butt welds nyob rau hauv cov kev pab cuam feem ntau yog kuaj los ntawm ultrasonic los yog radiographic kuaj.
FAQ
Q: Dab tsi yog cov yam ntxwv ntawm cov tshuaj muaj pes tsawg leeg ntawm Q345D steel yeeb nkab?
Q345D yog qhov qis- alloy siab- lub zog steel qauv nrog cov pa roj carbon tswj hauv qab 0.18% los tiv thaiv vuam kev ua tau zoo thiab tawv. Manganese yog qhov sib piv siab ntawm 1.00-1.60%, uas txhawb nqa lub zog thiab hardenability. Phosphorus thiab sulfur yog txhua qhov txwv rau 0.030% txhawm rau txo qhov txias brittleness thiab kub shortness, thiab kab ntxiv ntawm vanadium, niobium los yog titanium refine cov nplej thiab txhim kho qhov kub thiab txias cuam tshuam toughness.
Q: Dab tsi yog cov khoom siv ntawm Q345D steel yeeb nkab?
Qhov tsawg kawg nkaus yield zog yog 345 MPa, tensile zog yog 470-630 MPa thiab elongation yog tsawg kawg yog 22%. Qhov txawv qhov yuav tsum tau muaj yog tsawg-kub qhov cuam tshuam toughness tsawg kawg yog 34 J ntawm -20℃. Cov txiaj ntsig-rau-tensile piv yog capped ntawm 0.83, uas khaws cia ntawm cov yas deformation muaj peev xwm, thiab qib yog li ntawd nyiam dua Q345B hauv cov cheeb tsam txias thiab hauv cov qauv dynamically loaded.
Q: Dab tsi yog qhov txawv ntawm Q345D thiab Q345B?
Q345D muaj qis phosphorus thiab sulfur txwv, yuav tsum tau muab xa mus rau hauv cov xwm txheej zoo li qub es tsis txhob kub dov, thiab nqa ib qho yuav tsum tau ua -20℃cuam tshuam qhov yuav tsum tau muaj tsawg kawg yog 34 J. Nws kuj feem ntau muaj micro-alloying ntxiv ntawm niobium thiab vanadium. Cov kev sib txawv no ua rau Q345D xaiv qhov raug rau qis- kev pabcuam kub thiab kev ntxhov siab, ntawm tus nqi qis tshaj Q345B.
Q: Dab tsi kub ntau yog Q345D steel yeeb nkab haum rau?
Qhov ntsuas kub tsim yog -20℃rau +350℃. Hauv qab no -20℃qhov cuam tshuam lub zog yuav tsum raug txheeb xyuas raws li qhov yuav tsum tau ua, feem ntau yog -30℃tus nqi ntawm yam tsawg 27 J. Saum toj no 350℃nyob rau hauv lub sij hawm ntev load lub zog maj mam poob thiab ib tug kub-resistant qib xws li 15CrMoG ua qhov kev xaiv zoo dua. Nyob rau hauv qhov chaw txias heev, qhov tsim nyog ntawm qib yuav tsum raug ntsuas rau txhua daim ntawv thov.
Q: Dab tsi yog qhov yuav tsum tau rau kev xa khoom ntawm Q345D steel yeeb nkab?
Q345D yeeb nkab xa tuaj rau hauv cov xwm txheej zoo li qub (N) kom cov qauv tsis sib xws thiab qis - kub toughness yog txhim khu kev qha. Normalizing muaj cua sov mus rau 880-920 degree, tuav li 1.5 feeb ib millimeter ntawm phab ntsa thickness thiab cua txias, nrog ib tug ntev tuav rau phab ntsa saum 40 hli. Cov ntaub ntawv kho cua sov thiab cov ntawv ceeb toom kev sim tshuab yuav tsum muaj nrog cov ntaub ntawv xa khoom.
