Specifications rau ASTM A387 Qib 12 Alloy Steel Phaj
ASTM A387 / A387M: Txheem Specification rau Cov Phaj Siab Vessel, Alloy Steel, Chromium-Molybdenum
Qhov kev qhia tshwj xeeb no suav nrog chromium-molybdenum alloy steel daim hlau npaj rau fusion-welded boilers thiab cov hlab ntsha siab tsim los rau qhov kub thiab txias.
Qib 12 yog ib qho ntawm cov txheej txheem raws li qhov kev qhia tshwj xeeb no. Hauv qab no yog cov ntsiab lus tseem ceeb rau ASTM A387 Qib 12 Chav Kawm 1 thiab Chav Kawm 2.
1. CHEMICAL COMPOSITION (Kev Ntsuas Kub)
| Element | Qib 12, Chav Kawm 1 (%) | Qib 12, Chav Kawm 2 (%) |
|---|---|---|
| Cov pa roj carbon (C) | 0.10 max | 0.10 - 0.20 |
| Manganese (Mn) | 0.30 - 0.80 | 0.30 - 0.80 |
| Phosphorus (P) | 0.025 max | 0.025 max |
| Sulfur (S) | 0.025 max | 0.025 max |
| Silicon (Si) | 0.15 - 0.50 | 0.15 - 0.50 |
| Chromium (Cr) | 0.80 - 1.25 | 0.80 - 1.25 |
| Molybdenum (hli) | 0.44 - 0.65 | 0.44 - 0.65 |
Lus Cim: Chav Kawm 1 yog rau qis zog, haum rau annealing; Chav Kawm 2 muaj cov pa roj carbon ntau dua rau lub zog siab dua, feem ntau yog siv rau hauv cov xwm txheej zoo li qub thiab tempered.
2. Mechanical ProPERTIES
Cov cuab yeej raug txiav txim siab los ntawm cov qauv kuaj ib txwm muaj thiab tempered (Class 2) lossis raws li -annealed (Class 1).
Qib 12, Chav Kawm 1:
Tensile zog: 380 - 550 MPa (55 - 80 ksi)
Yield zog (min): 205 MPa (30 ksi)
Elongation hauv 50 hli (2 nti) (min): 22%
Qib 12, Chav Kawm 2:
Tensile zog: 485 - 620 MPa (70 - 90 ksi)
Yield zog (min): 275 MPa (40 ksi)
Elongation hauv 50 hli (2 nti) (min): 20%
3. Kev kho cua sov
Chav Kawm 1: Cov phaj feem ntau yog muab rau hauv qhov mob annealed (tag nrho anneal lossis isothermal anneal).
Chav Kawm 2: Cov phaj feem ntau muab nkag rau hauv qhov qub thiab tempered.
Normalizing kub: ~ 900℃(1650℃F)
Tempering Kub: ~ 650℃(1200℃F) yam tsawg kawg nkaus.
Tom qab-weld heat treatment (PWHT) tau pom zoo rau kev tsim kho kom txo tau qhov kev ntxhov siab thiab rov ua kom sov- thaj chaw cuam tshuam (HAZ) cov khoom.
4. YUAV TSUM TAU TXAIS
Chav Kawm 1 (Annealed): Feem ntau, qhov siab tshaj plaws Brinell hardness ntawm 163 HBW.
Chav Kawm 2 (Normalized & Tempered): Brinell hardness feem ntau nyob rau hauv thaj tsam ntawm 140-207 HBW.
5. KEV TIV THAIV
Kev ntsuam xyuas cuam tshuam (Charpy V-notch) tsis yog qhov yuav tsum tau ua ntawm lub hauv paus specification A387 tab sis yogfeem ntau teev nyob rau hauv kev yuav khoomrau kev siv lub nkoj siab (piv txwv li, tom qab ASME BPVC Tshooj II).
Thaum tau teev tseg, qhov ntsuas kub thiab qhov tsawg kawg nkaus absorbed zog qhov tseem ceeb (xws li, 20 J avg ntawm -30 degree) yuav tsum tau pom zoo los ntawm cov neeg yuav khoom thiab cov neeg muag khoom.
6. METALLURGY & WELDABILITY
Hom: Tsawg- alloy, chromium-molybdenum (Cr-Mo) steel.
Thawj Alloying Effects:
Chromium: Txhim kho oxidation thiab corrosion kuj ntawm qhov kub thiab txias.
Molybdenum: Ua kom muaj zog ntawm qhov kub thiab txias thiab txo qhov cuam tshuam rau temper embrittlement.
Weldability: Zoo, tab sis yuav tsum tau tswj nruj heev. Preheating (150-250℃/ 300{5}}}480℃F) thiab kev tswj qhov kub thiab txias yog qhov tseem ceeb los tiv thaiv hydrogen-induced cracking (HIC). Yuav tsum tau welded nrog tsawg-alloy electrodes (piv txwv li, E8018-B2).
7. COV KEV PAB CUAM
Cov hlab ntsha siab ua haujlwm ntawm qhov kub siab (txog ~ 525℃/ 975℃F).
Reactors, tshav kub exchangers, thiab distillation kab nyob rau hauv petrochemical thiab refining industries.
Chav boilers thiab superheater seem hauv kev tsim hluav taws xob.
Hydrocracking thiab hydrodesulfurization units.
8. QHOV TSEEM CEEB
UNS: K11762
ASME:SA-387 Gr.12
EN / DIN:13CrMo4-5 (zoo ib yam, tsis meej)
JIS:SWV 420
9. KEV PAB CUAM
Thaum xaj ASTM A387 Qib 12 daim hlau, cov hauv qab no yuav tsum tau teev tseg:
ASTM Kev Tsim Kho thiab Qib (A387 Qib 12).
Chav Kawm (1 lossis 2).
Dimensions (thickness, dav, ntev).
Kev kho cua sov (yog tias tsis yog tus qauv).
Kev xeem yuav tsum tau (xws li, ntxiv flattening xeem, kuaj ultrasonic ib ASTM A578).
Txhua qhov kev xav tau ntxiv los ntawm qhov tshwj xeeb S1-S18.
Lus Cim Tseem Ceeb:Qhov no yog cov ntsiab lus rau cov ntaub ntawv xov xwm. Txhawm rau ua kom tiav, cov ntaub ntawv pov thawj, suav nrog kev ua siab ntev, kev sim, thiab qhov yuav tsum tau ua, nco ntsoov sab laj tus qauv tshiab ASTM A387 / A387M.
1. Dab tsi yog qhov kev tshaj tawm -weld heat treatment (PWHT) kub thiab tuav lub sij hawm rau A387 Gr.12 Cl.2?
Rau A387 Qib 12 Chav Kawm 2, qhov raug pom zoo Post-Weld Heat Treatment (PWHT lossis kev ntxhov siab) qhov kub thiab txias yog 1100℃F txog 1250℃F (595℃txog 675℃). Lub sij hawm tuav feem ntau yog tsawg kawg yog 1 teev ib nti (25 hli) ntawm tuab, nrog rau qhov tsawg kawg nkaus ntawm 1 teev tag nrho. Cov txheej txheem no yog ib qho tseem ceeb los txo cov kev ntxhov siab ntawm vuam, ua kom sov sov- thaj tsam cuam tshuam (HAZ), thiab rov ua kom muaj zog corrosion, ua kom muaj kev ncaj ncees ntawm cov khoom siv hluav taws xob siab.
2. Vim li cas qhov preheating yuav tsum tau ua ntej vuam A387 Gr.12 Cl.2 steel?
Preheating, feem ntau nyob rau hauv thaj tsam ntawm 300℃F mus rau 450℃F (150℃rau 230 degree), yog yuav tsum tau rau vuam A387 Qib 12 hoob 2 los tiv thaiv hydrogen -induced cracking (HIC), kuj hu ua txias cracking. Qhov no alloy lub hardenability yuav ua rau ib tug nkig microstructure nyob rau hauv lub weld cheeb tsam thaum txias ceev. Preheating slows tus nqi cua txias, tso cai rau hydrogen diffuse tawm thiab txo txoj kev pheej hmoo ntawm kev sib tsoo - martensite susceptible martensite, yog li ua kom lub suab, tsis xws luag - weld dawb.
3. Dab tsi yog qhov siab tshaj qhov kev pabcuam kub rau A387 Gr.12 Cl.2 daim hlau?
Qhov siab tshaj plaws tau pom zoo ua haujlwm kub kub rau ASTM A387 Qib 12 Chav Kawm 2 daim hlau feem ntaumus txog 1000℃F (540 degree). Ntawm qhov ntsuas kub siab no, cov ntsiab lus chromium muab kev tiv thaiv zoo rau oxidation (scaling) thiab corrosion, thaum molybdenum txhim kho lub zog thiab txo qis. Rau kev pabcuam saum toj no qhov kub thiab txias, qib nrog cov ntsiab lus chromium siab dua (zoo li Qib 11 lossis 22) feem ntau suav hais tias.
Tag nrho cov specification thiab cov ntsiab lus muaj nyob rau ntawm kev thov. Cov ntaub ntawv saum toj no yog muab rau kev taw qhia nkaus xwb. Rau kev tsim tshwj xeeb thov hu rau peb cov neeg ua haujlwm muag khoom.
