1. Qhov tseem ceeb ua rau muaj kev cuam tshuam tsawg-kub
A. Tshuaj lom neeg muaj pes tsawg leeg
A423's Tsawg-alloy tsim(CU, CR, P) Ua ntej ua kom sov ua ntej tshaj tawm txog huab cryogenic nyuaj. Piv rau cov hlau txias-resistant steels (piv txwv li, Astm A333 qib 6):
Siab dua phosphorus (p): Tuaj yeem nce brittleness ntawm tsawg kub.
Tsawg Nickel (NI): Lacks the nickel content (~3–9%) that enhances cryogenic toughness in steels like ASTM A352 LC3.
B. Microstructure
Ferrite-Pearlite Matrix: Txheem rau huab cua cov hlau; tsawg dua du ntau duaAUSTENITIClossisNickel-alloyed steelsntawm subzero kub.
2. Kev ua tau los ntawm qhov kub thiab txias
| Qho so | Kev coj tawv | Pom zoo ua |
|---|---|---|
| 0 Qib rau -30 degree(32℃f rau -22℃f) | Tsim lees txaisRau cov ntawv thov cov txheej txheem feem ntau; Charpy V-Notch tseem ceeb tshaj qhov ua tau raws li ASTM A423 cov nqi tsawg kawg nkaus. | Tsis muaj qhov tshwj xeeb. |
| -30℃rau -40 degree(-22 Qib F rau -40 Degree F) | Yuav luag tsis tau; Kev cuam tshuam hluav taws xob yuav poob qis. Brittle Bacture kev pheej hmoo nce zuj zus. | Xyuas cov kev ntsuas charpy ntawm kev pabcuam kub. |
| Hauv qab -40 degree (<−40°F) | Kev pheej hmoo siab ntawm brittle brecure; Tsis pom zoo rau cov khoom lag luam tseem ceeb-cov kabmob. | Kev sivTsawg-Kub Cov Hlau(piv txwv li, Astm A333 gr . 6). |
3. Kuaj cov qauv rau kev ua pov thawj
Charpy V-Nti Kuaj (Astm A370): Kev ntsuas cuam tshuam lub zog (Joules / FT-LB) ntawm cov ntsuas kub teev.
Raug A423 Xav Tau: Ntau dua los yog sib npaug rau 20 j (15 ft-lb) ntawmChav Chav Kub(sib txawv los ntawm cov chaw tsim khoom).
Rau Tsawg-temp Siv: Xav tauKev Kuaj Ntxiv(piv txwv li, -30 degree) kom paub meej tias haum.
4. Kev sib piv rau lwm cov hlau
| Qib hlau | Siv cov ntaub ntawv | Tsawg-temp Txwv | Qhov Tseem Ceeb |
|---|---|---|---|
| A423 Weathering | Cov Qauv Sab Nraud Sab Nraud | -30 Qib (-22 Qib F) | Kev tiv thaiv tus kheej xeb txheej. |
| ASTM A333 gr . 6 | Cryogenic piping | -45℃(-50℃f) | Npib tsib xee-txuam rau Arctic mob. |
| ASTM A516 Gr . 70 | Siab | -40 Qib (-40℃f) | Normalized rau kev txhim kho todness. |
5. Kev pab cov tswv yim rau cov huab cua txias
Cov Khoom Siv Khoom Hloov:
Rau qhov kub<−30°C, switch to ASTM A333 Qib 6(Ni-alloyed) lossisA537 chav kawm 2(cua sov-kho).
Kev tsim kho kho kom haum:
Zam kev hloov pauv tsis zoo / cov kev hloov tuab los txo cov kev ntxhov siab.
Tom qab weld kev kho cua sov (pwht):
Txo cov lus qhia txog kev ntxhov siab uas ua rau muaj kev sib cav.
Tag
A423 Huab Cua Hlau yogtsis tau zoo rau kev mob khaub thuas heevTab sis ua yeeb yam zoo nyob rau hauvCov huab cua tsav tsheb me me(Ntau dua los yog sib npaug ntawm -30 degree). Rau ib puag ncig txias:
Txheeb xyuas cov ntaub ntawv tawvVia Charpy kuaj cov dej num tshwj xeeb.
Txiav txim siab xaivYog tias brittle bacture yog qhov kev pheej hmoo tseem ceeb.
