1. ASTM A671 CJA115 Class 70 Steel Pipe yog dab tsi?
Teb:
ASTM A671 CJA115 Chav Kawm 70 yog ib qhohluav taws xob -fusion-welded (EFW) steel yeeb nkabtsim rauqis- kub thiab siab - kev pabcuam siab(rated rau-50 ° F / -45 ° C). Cov yam ntxwv tseem ceeb:
Khoom Qib:CJA115 (carbon steel nrog tswj chemistry).
Chav Kawm 70:Qhia aYam tsawg kawg nkaus tawm lub zog ntawm 70 ksi (483 MPa).
Txuj kev ua raws cai:Raws li ASTM A671 rau fabricated kav siv nyob rau hauv cryogenic / siab daim ntaub ntawv.
2. Cov cuab yeej siv tshuab thiab tshuaj lom neeg yog dab tsi?
Teb:
Mechanical Properties:
Yield Strength: Ntau dua lossis sib npaug rau 70 ksi (483 MPa).
Tensile zog: 80-100 ksi (552-690 MPa).
Impact Test: Charpy V-notch xav tau ntawm-50℃Fkom ntseeg tau tias qis -kub toughness.
Chemical Composition (zoo ib yam):
Carbon (C): Tsawg dua lossis sib npaug li 0.30%, Manganese (Mn): 0.90–1.35%, Phosphorus / Sulfur (P / S): Tsawg dua lossis sib npaug li 0.035%.
3. Cov kev siv zoo li cas ntawm Chav Kawm 70 Pipes?
Teb:
Kev Siv Tseem Ceeb:
LNG (liquefied natural gas) pipelines.
Cryogenic cia tso tsheb hlau luam (-45℃ib puag ncig).
Siab - siab kis tau tus mob nyob rau hauv cov cheeb tsam arctic.
Kev lag luam:Roj & roj, petrochemical, fais fab nroj tsuag.
4. Chav Kawm 70 Piv rau Lwm Cov Chav Kawm ASTM A671 li cas?
Teb:
| Chav kawm | Yield zog (ksi) | Qhov txawv tseem ceeb |
|---|---|---|
| Chav Kawm 55 | 55 | Lub zog qis dua, dav dav qis -temp siv |
| Chav Kawm 63 | 63 | Siab siab |
| Chav Kawm 70 | 70 | Siab siab / cryogenic |
| Chav kawm 70 yog qhov nyiam rauxav tau ntau lub siabtshaj chav kawm 63. |
5. Fabrication thiab Vuam Cov Txheej Txheem?
Teb:
Vuam:Preheat (200–350℃F) thiab PWHT (Post-Weld Heat Treatment) feem ntau yuav tsum tau ua kom tsis txhob muaj qhov txias txias.
Kev sim:Yuav tsum tau kuaj hydrostatic + kuaj tsis muaj kev puas tsuaj (piv txwv li, radiography lossis ultrasonic).
Kev tsim: Cold bending needs stress relief for wall thickness >1 nti (25.4 hli).
