BV D420 thiab BV D500 yog siab - lub zog shipbuilding thiab offshore structural steel daim hlau ntawv pov thawj los ntawm Bureau Veritas (BV). Cov qib no yog tsim los rau kev xav tau kev siv dej hiav txwv, suav nrog kev tsim lub nkoj, cov chaw tawm sab nrauv, thiab lwm yam tseem ceeb uas lub zog zoo, tawv, thiab weldability yog qhov tseem ceeb los xyuas kom muaj kev ncaj ncees thiab kev nyab xeeb hauv qhov chaw hnyav.
Qhov txawv tseem ceeb:
Qhov tseem ceeb sib txawv yog lawv qhov tsawg kawg nkaus yield zog. BV D420 muaj lub zog tawm los ntawm 420 MPa, thaum BV D500 muab lub zog siab dua ntawm 500 MPa. Qhov no tso cai rau D500 los txhawb nqa ntau dua lossis ua kom hnyav dua -txuag tsim los ntawm kev txo phaj thickness piv rau D420.
Txhawm rau kom tau txais nws lub zog txhim kho, D500 feem ntau yog tsim los nrog cov txheej txheem tsim thiab kev tsim khoom nruj dua. Nws yog feem ntau muab nkag rau hauv ib qho quenched thiab tempered (Q&T), uas muab nws zoo -grained microstructure rau ob qho tib si siab zog thiab zoo toughness. Hauv qhov sib piv, D420 feem ntau yog muab rau hauv qhov qub lossis thermo-mechanically tswj ua tiav (TMCP) xeev. Yog li ntawd, fabrication xav tau txawv heev. Vuam BV D500 yuav tsum muaj cov txheej txheem nruj dua, suav nrog kev tswj xyuas qhov ntsuas kub ua ntej, cov khoom siv hluav taws xob, thiab cov khoom muaj peev xwm tshaj tawm -weld heat treatment kom tsis txhob muaj hydrogen-induced cracking thiab khaws nws cov khoom. D420 feem ntau yog kev zam txim ntau dua thiab yooj yim rau kev tsim. Qhov kev xaiv ntawm lawv suav nrog kev ntsuas qhov xav tau ntawm lub zog siab dua (D500) tiv thaiv cov yam xws li kev tsim khoom nyuaj, qhov project specifications, thiab tag nrho cov nqi.
Tshuaj muaj pes tsawg leeg
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BV D420 ntxiv Cov Khoom Siv Hluav Taws Xob Muaj Zog Tempering thiab Quenching |
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Qib |
Cov ntsiab lus Max (%) |
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|
C |
Si |
Mn |
P |
S |
Al (min) |
N |
|
|
BV D420 |
0.20 |
0.55 |
1.70 |
0.030 |
0.030 |
0.015 |
0.020 |
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BV D500 ntxiv High Strength Chemical Composition Tempering thiab Quenching |
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Qib |
Cov ntsiab lus Max (%) |
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|
C |
Si |
Mn |
P |
S |
Al (min) |
N |
|
|
BV D500 |
0.20 |
0.55 |
1.70 |
0.030 |
0.030 |
0.015 |
0.020 |
Mechanical Property
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BV D420 ntxiv Cov khoom muaj zog siab hauv Tempering thiab quenching |
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Qib |
Mechanical Property |
Charpy V Impact Test |
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|
Yield |
Tensile |
Elongation |
Qib |
Zog 1 |
Zog 2 |
|
|
BV D420 |
Min Mpa |
Mpa |
Tsawg% |
-20 |
J |
J |
|
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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BV D500 ntxiv Cov khoom muaj zog siab hauv Tempering thiab quenching |
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Qib |
Mechanical Property |
Charpy V Impact Test |
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Yield |
Tensile |
Elongation |
Qib |
Zog 1 |
Zog 2 |
|
|
BV D500 |
Min Mpa |
Mpa |
Tsawg% |
-20 |
J |
J |
|
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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