ASTM A350, npe hu uaTxheem Specification rau Carbon thiab Low-Alloy Steel Forgings, Yuav Tsum Tau Qhov Ntsuas Toughness Test rau Piping Cheebtsam, yog tus qauv tseem ceeb tsim thiab tswj hwm los ntawm ASTM International, dav siv hauv kev lag luam xws li roj thiab roj, petrochemicals, thiab hluav taws xob tsim hluav taws xob rau cov kev pabcuam kub kub ASTM International. Hauv qab no yog cov ncauj lus kom ntxaws:
1. Scope thiab Core Purpose
Cov qauv no qhia txog cov kev xav tau raucarbon thiab low-alloy steel forgings(xws li forged / nplhaib-dov flanges, forged fittings, thiab li qub) feem ntau yog siv rau hauv qhov kev pab cuam uas tsis tshua muaj kub, nrog rau kev ua kom pom tseeb ntawm qhov tsis sib haum xeeb kom ntseeg tau tias cov khoom tiv thaiv cov pob txha tawg nyob rau hauv qhov kub thiab txias thiab kev nyuaj siab concentrationsASTM International. Nws tsis npog raw cov ntaub qhwv los yog seamless tubular cov ntaub ntawv, tsuas yog cov kav dej tiav ua tiav cov qauv tsim xws li ASME B16.5 lossis API specs. Tus qauv muaj nyob rau hauv ob qho tib si nti-phaus (A350) thiab SI (A350M) units.
2. Cov khoom tseem ceeb qib thiab cov chav kawm
ASTM A350 suav nrog ntau qib raws li qhov sib txawv ntawm qhov kub thiab txias thiab kev xav tau ntawm txhua yam, nrog rau cov qib sib txawv raws li hauv qab no:
| Qib | Hom | Daim ntawv thov | Class Distinction |
|---|---|---|---|
| LF1 | Cov pa roj carbon steel | General low-temp piping Cheebtsam | Chav Kawm 1 (Kev tshuaj xyuas nruj UT), Chav Kawm 2 |
| LF 2 | Tsawg-carbon manganese hlau | Siv dav hauv LNG, offshore low-temp systems (piv txwv li, koj ASTM A350 GR LF2 CL1) | Chav Kawm 1 (UT xav tau), Chav Kawm 2 |
| LF3 | Nickel-alloyed hlau | Qhov ntsuas kub qis (-60℃/-76℃F) kev pabcuam | Chav Kawm 1, Chav Kawm 2 |
| LF5 | Carbon-molybdenum hlau | High-temp / low-temp ua ke kev pabcuam | Chav Kawm 1, Chav Kawm 2 |
| LF 6 | Nickel-chromium-molybdenum hlau | Ultra-low-kub (-101℃/-150℃F) daim ntawv thov | Chav Kawm 1, Chav Kawm 2 |
3. Kev tsim khoom thiab kev kho cua sov yuav tsum tau ua
Txheej txheem melting: Hlau yuav tsum tau melted ntawm open-hearth, yooj yim oxygen, hluav taws xob rauv, los yog nqus-induction melting, nrog txaus muab pov tseg kom tsis txhob muaj qhov tsis xws luag xws li segregationASTM International.
Forging: Yuav tsum tau forging txheej txheem los xyuas kom meej grain qauv thiab txhua yam khoom.
Kev kho cua sov: Cov txheej txheem yuav tsum muaj xws li normalizing, tempering, quenching, lossis nag lossis daus hardening, nyob ntawm qib, txhawm rau txhim kho toughness thiab lub zogASTM International.
4. Cov kev xav tau tseem ceeb
4.1 Tshuaj muaj pes tsawg leeg
Kev txwv nruj rau cov ntsiab lus xws li C, Mn, P, S, Si, Ni, Cr, thiab Mo raug tswj los ntawm kev ntsuas kub thiab kev tshuaj xyuas cov khoom kom lav cov khoom ua tau zoo thiab weldabilityASTM International. Piv txwv li, qib LF2 muaj qhov siab tshaj plaws C cov ntsiab lus ntawm 0.30%.
4.2 Mechanical Properties
Kev Ntsuas TensileRaws li ASTM A370; LF2 Chav Kawm 1 muaj lub zog tensile yam tsawg kawg nkaus ntawm 485 MPa (70 ksi) thiab tawm lub zog ntawm 275 MPa (40 ksi).
Notch Toughness (Charpy V-Notch): Ib qho kev xav tau tseem ceeb. Rau LF2 Chav Kawm 1, qhov kev ntsuam xyuas tau ua nyob rau ntawm -46℃(-51℃F), nrog rau 3-specimen nruab nrab qhov cuam tshuam lub zog Ntau dua lossis sib npaug rau 20 J (15 ft-lbf) thiab ib qho piv txwv tsawg tshaj lossis sib npaug rau 16 J (12 ft-lbf).
Kev kuaj Hardness: Ntsuas raws li ASTM A370 kom tsis txhob muaj qhov tawv tawv heev uas yuav txo tau qhov hnyav.
4.3 Kev Tshawb Fawb thiab Kev Ntsuas
Cov kev xeem uas yuav tsum tau muaj xws li tshuaj ntsuam xyuas, tensile xeem, cuam tshuam, kuaj hardness, kuaj ultrasonic (UT) rau Class 1 forgings, thiab hydrostatic kuaj rau siab-muaj Cheebtsam ASTM International. Cov kev xav tau ntxiv (xws li, NDT ntxiv) tuaj yeem teev los ntawm tus neeg yuav khoom.
5. Qhov tseem ceeb thiab daim ntawv thov scenarios
ASTM A350 yog tus qauv ntsuas rau qhov ntsuas kub tsis zoo, ua kom muaj kev ntseeg siab ntawm cov khoom tseem ceeb hauv cov cheeb tsam hnyav xws li offshore roj platforms, LNG nroj tsuag, thiab cov kav dej hauv cheeb tsam txias. Rau koj qhov project Oman's ASTM A350 GR LF2 CL1 tivthaiv, tus qauv no tau lees paub ua raws li qhov xav tau ntawm qhov kub thiab txias, thaum daim ntawv "OF SPEC" qhia tias xav tau kev rov ua haujlwm lossis hloov pauv kom tau raws li qhov project muaj kev nyab xeeb thiab cov qauv zoo.
