DNV D420 yog lub siab - lub zog steel phaj ntawv pov thawj los ntawm DNV (Det Norske Veritas) rau kev siv dej hiav txwv thiab sab nrauv. Qhov kev xaiv "D" qhia tau hais tias cov khoom muaj kev cuam tshuam toughness yog kuaj thiab lav ntawm qhov kub nruab nrab ntawm -20℃. Tus naj npawb "420" qhia qhov tsawg kawg nkaus lub zog ntawm 420 MPa. Nws muaj lub zog tensile xws li 530 txog 680 MPa thiab qhov tsawg kawg nkaus elongation ntawm 18% rau thicknesses txog 150mm. Kev cuam tshuam lub zog xav tau yog feem ntau 28J (transverse) lossis 42J (ntev) ntawm -20 degree. Cov tshuaj muaj pes tsawg leeg muaj cov pa roj carbon tsawg dua lossis sib npaug li 0.20% thiab manganese Tsawg dua lossis sib npaug li 1.70%. Qib no muaj qhov zoo tshaj plaws weldability thiab formability, ua rau nws yog ib tug nqi-zoo xaiv rau dav shipbuilding thiab marine lug.
DNV D500 yog ib qho ntxiv -siab- lub zog steel phaj kuj tau lees paub los ntawm DNV nrog rau kev cuam tshuam toughness kuaj ntawm -20℃. Lub "500" qhia txog qhov tsawg kawg nkaus tawm lub zog ntawm 500 MPa . Nws muaj lub zog tensile xws li 610 txog 770 MPa thiab qhov tsawg kawg nkaus elongation ntawm 16% rau thicknesses txog 150mm. Kev cuam tshuam lub zog xav tau siab dua, ntawm 33J (transverse) lossis 50J (ntev) ntawm -20 degree. Cov tshuaj muaj pes tsawg leeg yog tswj nruj me ntsis nrog cov pa roj carbon tsawg dua lossis sib npaug li 0.20% thiab manganese Tsawg dua lossis sib npaug li 1.70%. Qib no yuav tsum tau ua tiav zoo li quenching thiab tempering (QT) lossis TMCP kom ua tiav nws cov khoom siv kho tshuab. Nws yog qhov tsim nyog rau kev thov cov khoom siv hauv nkoj tsim thiab mobile offshore drilling units qhov twg yuav tsum muaj lub zog zoo dua.
Ob leeg DNV D420 thiab DNV D500 yog DNV- ntawv pov thawj siab - lub zog marine steels nrog kev cuam tshuam toughness kuaj ntawm -20 degree, kom ntseeg tau tias kev ua tau zoo nyob rau hauv qhov chaw txias marine. Lawv qhov sib txawv tseem ceeb nyob rau hauv lub zog theem: D420 muaj qhov tsawg kawg nkaus tawm lub zog ntawm 420 MPa nrog tensile zog ntawm 530-680 MPa, haum rau dav dav -lub zog hull kev tsim kho uas zoo heev fabricability yog qhov tseem ceeb, thaum D500 muab ib tug ntau dua yield zog ntawm 50}70 MPa mus txog 10 610 MPa { MPa, tsim los rau kev thov ntau dua load-bearing daim ntaub ntawv uas yuav tsum tau superior zog-rau-hnyav piv. Ob qib tshwj xeeb tswj cov tshuaj muaj pes tsawg leeg nrog cov pa roj carbon tsawg dua lossis sib npaug li 0.20% thiab manganese Tsawg dua lossis sib npaug li 1.70%, thiab D500 yuav tsum tau ua tiav ntau dua li QT lossis TMCP kom ua tiav nws cov khoom siv kho kom zoo dua qub thaum tuav cov weldability zoo rau kev pabcuam marine tseem ceeb.
Tshuaj muaj pes tsawg leeg
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DNV D420 ntxiv muaj zog Chemical Composition |
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Qib |
Cov ntsiab lus Max (%) |
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C |
Si |
Mn |
P |
S |
Al |
N |
|
|
NWS D420 |
0.20 |
0.10-0.55 |
1.7 |
0.030 |
0.030 |
0.015-0.08 |
0.020 |
|
Nb |
V |
Ti |
Cu |
B |
Ni |
Mo |
|
|
0.02-0.05 |
0.04-0.10 |
0.02 |
|
0.005 |
|
|
|
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DNV D500 ntxiv muaj zog Chemical Composition |
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|
Qib |
Cov ntsiab lus Max (%) |
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|
C |
Si |
Mn |
P |
S |
Al |
N |
|
|
DNV D500 |
0.20 |
0.10-0.55 |
1.7 |
0.030 |
0.030 |
0.015-0.08 |
0.020 |
|
Nb |
V |
Ti |
Cu |
B |
Ni |
Mo |
|
|
0.02-0.05 |
0.04-0.10 |
0.02 |
|
0.005 |
|
|
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Mechanical Property
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DNV D420 ntxiv cov khoom muaj zog dav dav |
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|
Qib |
|
Mechanical Property |
Charpy V Impact Test |
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Thickness |
Yield |
Tensile |
Elongation |
Qib |
Zog 1 |
Zog 2 |
|
|
NWS D420 |
mm |
Min Mpa |
Mpa |
Tsawg% |
-20 |
J |
J |
|
t Tsawg dua lossis sib npaug li 50 |
420 |
530-680 |
18% |
28 |
42 |
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50＜t Tsawg dua lossis sib npaug rau 70 |
420 |
530-680 |
18% |
28 |
42 |
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70＜t Tsawg dua lossis sib npaug rau 150 |
420 |
530-680 |
18% |
28 |
42 |
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Lus Cim: Lub Zog 1 yog qhov kev ntsuas cuam tshuam, Lub Zog 2 yog qhov ntev |
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DNV D500 ntxiv cov khoom muaj zog dav dav |
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|
Qib |
|
Mechanical Property |
Charpy V Impact Test |
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|
Thickness |
Yield |
Tensile |
Elongation |
Qib |
Zog 1 |
Zog 2 |
|
|
DNV D500 |
mm |
Min Mpa |
Mpa |
Tsawg% |
-20 |
J |
J |
|
t Tsawg dua lossis sib npaug li 50 |
500 |
610-770 |
16% |
33 |
50 |
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50＜t Tsawg dua lossis sib npaug rau 70 |
500 |
610-770 |
16% |
33 |
50 |
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70＜t Tsawg dua lossis sib npaug rau 150 |
500 |
610-770 |
16% |
33 |
50 |
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Lus Cim: Lub Zog 1 yog qhov kev ntsuas cuam tshuam, Lub Zog 2 yog qhov ntev |
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