ASTM B338 Qib 2 UNS R50400 Titanium Tube rau Condensers thiab Kub Exchangers
Sep 09, 2025
Qib 2 Titanium thiab nws qib sib npaug
Qib 2 titanium yog cov neeg ua haujlwm ntawm kev lag luam -purity titanium. Nws yog unalloyed, nrog ib tug me ntsis oxygen cov ntsiab lus uas muab ib tug pab tau ua ke ntawm lub zog thiab ductility, thiab nws yog lub neej ntawd kev xaiv rau condensers, phaj kub exchangers thiab tshuaj txheej txheem tubing ua hauj lwm nyob rau hauv seawater, chlorides thiab me ntsis txo cov xov xwm. Nws cov cim qhia thoob plaws cov txheej txheem yog:
| Qhov system | Lub npe | Txuj |
|---|---|---|
| ASTM | Qib 2 | ASTM B338, B265, B348 |
| UNS | R50400 | Unified numbering system |
| DIN / EN | W. Nr . 3.7035 | Titanium khoom naj npawb |
| Tuam Tshoj | TA 2 | GB/T 3620.1 |
| ASME | SB338 Qib 2 | Kev pabcuam siab version |
Tus lej German cov khoom siv rau Qib 2 yog 3.7035. Tus nqi 3.7034 uas tshwm nyob rau hauv qee lub npe catalog thiab cov nplooj ntawv cov ntaub ntawv yog qhov yuam kev typographical thiab yuav tsum tsis txhob muab tso rau ntawm daim ntawv xaj khoom, vim nws yuav tsis daws rau Qib 2 hauv cov ntaub ntawv database.
Chemistry thiab Mechanical Property Limits
Qib 2 yog titanium uas txhob txwm tshaj tawm cov pa oxygen rau lub zog thiab nruj tswj cov interstitials. Titanium cov ntsiab lus nominally 99.2% thiab siab dua nrog cov nyiaj seem seem hauv qab no.
| Element | Limit (wt%) |
|---|---|
| Ti | Tshuav |
| O | 0.25 max |
| Fe | 0.30 max |
| C | 0.08 max |
| N | 0.03 max |
| H | 0.015 max |
| Lwm tus | 0.10 txhua, 0.40 tag nrho max |
| Property (ntxiv) | Yam tsawg kawg nkaus | Hom |
|---|---|---|
| Tensile zog | 345 MPa (50 ksi) | 450 txog 520 MPa |
| Yield zog, 0.2% offset | 275 MPa (40 ksi) | 310 txog 380 MPa |
| Elongation nyob rau hauv 50 mm | 20% | 25% thiab siab dua |
| Hardness | Tsis tau teev tseg | Hais txog HV 150 txog 200 |
| Elastic modulus | Tsis tau teev tseg | 100-110 GPa |
| Qhov ntom | Tsis tau teev tseg | 4.51 g / cm3 |
Ob qhov kev thov feem ntau pom nyob rau hauv thib peb -cov ntsiab lus ntawm tog neeg yuav tsum raug kho. Ua ntej, Qib 2 tensile lub zog tsis tshaj 800 MPa nyob rau hauv lub annealed mob; tensile yam tsawg kawg nkaus yog 345 MPa thiab cov nqi raug nyob ze 480 MPa. Cov nqi siab tshaj 800 MPa yog rau cov qib ntxiv dag zog lossis rau cov khoom ua haujlwm txias heev. Qhov thib ob, qhov tsawg kawg nkaus tawm lub zog yog 275 MPa, tsis yog 345 MPa. Hloov daim duab tsis raug rau hauv kev ntsuas siab yog qhov teeb meem kev nyab xeeb, tsis yog qhov sib txawv. Oxygen rau Qib 2 yog 0.25% siab tshaj plaws; daim duab 0.18% siv rau Qib 1.
Condenser thiab Heat Exchanger Applications
Qib 2 raj dominates lub lag luam condenser rau ib qho yooj yim vim li cas: titanium muaj kev tiv thaiv zoo heev rau cov dej hiav txwv thiab cov tshuaj chloride, thiab nws cov zaj duab xis nyias nyias yog tus kheej - kho nyob rau hauv lub xub ntiag ntawm oxygen. Cov kev pabcuam ib txwm muaj xws li:
Chav dej condensers nyob rau hauv lub zog tsim thiab desalination, siv seawater los yog brackish dej txias.
Plhaub thiab tube exchangers nyob rau hauv refineries thiab tshuaj nroj tsuag uas muaj chlorides thiab me ntsis txo cov txheej txheem kua.
Phaj kub exchangers rau seawater txias ntawm kaw loops.
Cov cua txias, cov kav dej hiav txwv thiab cov dej tua hluav taws uas tsis muaj qhov hnyav thiab tiv thaiv cov tshuaj chloride pitting teeb meem.
Kev kho mob thiab cog cov khoom siv thaum ua rau ASTM F67 es tsis yog rau kev lag luam specification.
Feem ntau condenser raj qhov ntau thiab tsawg khiav los ntawm 19.05 mm mus rau 25.4 mm sab nraud txoj kab uas hla nrog cov phab ntsa ntawm roughly 0.7 mm thiab 1.25 mm, muab raws li ntev ntev los yog U-bent assemblies. Cov phab ntsa nyias nyias tuaj yeem ua tau vim tias titanium tiv thaiv kev yaig los ntawm cov dej hiav txwv huv huv ntawm cov dej ntws ib txwm muaj, tab sis cov phab ntsa tuab yuav tsum tseem ua rau lub raj txaus siab -rau-tubesheet sib koom ua ke thiab cov nyiaj yaig siv los ntawm tus tsim qauv.
Seawater thiab Dej Txias Service Limits
Oxygen yog qhov tseem ceeb. Titanium corrodes sai heev nyob rau hauv anoxic, acidic chloride ib puag ncig uas cov zaj duab xis repassivate, yog li nyob twj ywm, deaerated thiab sulphide -cov dej bearing xav tau kev soj ntsuam tshwj xeeb.
Kev txwv nrawm yog dav dav hauv cov dej hiav txwv huv, tab sis cov xuab zeb, grit thiab cov khib nyiab nkag mus ua rau yaig thiab yuav tsum tau muab tshem tawm sab saud.
Fluoride yog cov tshuaj lom neeg tseem ceeb. Txawm tias cov kab tawg ua rau cov yeeb yaj kiab tsis zoo, thiab cov kev pabcuam hydrofluoric acid tsis suav nrog.
Anhydrous methanol tuaj yeem ua rau muaj kev ntxhov siab corrosion tawg; qhuav chlorine saum toj no txog 75 C yog txhoj puab heev.
Hydrogen absorption nyob rau hauv cathodically tiv thaiv los yog galvanically sib txuas tshuab tuaj yeem ua rau hydriding thiab embrittlement yog tias lub peev xwm raug tsav tsis zoo.
ASME siab tsim tso cai rau unalloyed titanium, nrog rau Qib 2, txog li 315 C.
Fabrication thiab Vuam xyaum
Weld nrog roj tungsten arc nyob rau hauv tag nrho inert shielding. Ib lub ci nyiaj weld qhia tau hais tias muaj peev xwm siv tau roj; tej xim uas tsis yog lub teeb straw qhia tias muaj kab mob.
Muab cov ntaub thaiv rov qab thiab cov ntaub thaiv npog kom cov sib koom ua ke tiv thaiv kom txog thaum nws txias hauv qab li 400 C.
Tsis txhob siv cov tshuaj chloride-cov roj nplua nyeem, txiav cov kua lossis pleev xim. Chloride residues ntawm titanium nto ua qhov chaw pitting hauv zos.
Khaws cov pa roj carbon steel txhuam, clamps thiab nqa iav kom deb ntawm qhov chaw ua haujlwm; embedded hlau hais yog ib tug classic pib qhov chaw rau qhov corrosion.
Kev nthuav dav txias rau hauv tubesheets yog tus qauv rau condensers, tab sis kev nthuav dav yuav tsum tau tswj kom tsis txhob dhau - dov, uas ua rau muaj kev ntxhov siab hauv zos thiab tuaj yeem tawg cov phab ntsa nyias.
U- dabtsi yog khoov yuav tsum muaj ib tug dav khoov vojvoog thiab, rau nruj khoov, ib tug interstage los yog ncej- khoov anneal los kho ductility.
Feem ntau yuam kev hauv Qib 2 Cov Ntaub Ntawv
Muab cov pa oxygen ntawm 0.18% lossis qis dua raws li Qib 2 txwv, uas yog Qib 1 tus nqi.
Tshaj tawm tensile zog siab tshaj 800 MPa rau annealed Qib 2 raj.
Siv 345 MPa raws li qhov tsawg kawg nkaus tawm lub zog, tsis meej pem nrog lub zog tensile yam tsawg kawg nkaus.
Siv tus lej European cov ntaub ntawv uas tsis muaj nyob, lossis tsis meej pem Qib 2 nrog palladium- coj tus lej Qib 7.
Hais txog kev tiv thaiv corrosion hauv dej hiav txwv ntawm 100 C lossis siab dua yam tsis tau sau tseg tias cov ntaub ntawv anoxic lossis acidic txawv ntawm hom, tsis yog tus nqi xwb.
FAQ
Q: Qhov txawv ntawm Qib 2 thiab Qib 7 titanium yog dab tsi?
Qib 7 yog Qib 2 nrog 0.12% mus rau 0.25% palladium ntxiv rau kev tiv thaiv kom tsis txhob muaj cov kua qaub thiab crevice nres. Mechanical zog yeej tseem zoo tib yam.
Q: Dab tsi yog qhov tsawg kawg nkaus yield zog ntawm Qib 2?
275 MPa (40 ksi) ntawm 0.2% offset nyob rau hauv lub annealed mob. Lub zog tensile tsawg kawg yog 345 MPa (50 ksi).
Q: Qib 2 puas haum rau seawater condensers?
Yog, nyob rau hauv aerated seawater los yog dej brackish nrog ib txwm ntws velocities. Cov kev txwv yog cov dej anoxic acidic, cov ntsiab lus fluoride siab thiab tiv thaiv cathodic ntau dhau.
Q: Tus txheej txheem twg siv rau Qib 2 lub tshav kub exchanger raj?
ASTM B338 lossis ASME SB338 rau raj, nrog ASTM B265 npog daim ntawv thiab phaj thiab ASTM B348 npog bar thiab billet.
Q: Qib 2 lub raj puas tuaj yeem welded hauv thaj teb?
Yog, nrog rau cov roj inert shielding thiab tswj kev huv. Weld xim yog qhov kev lees paub zoo, thiab cov kab mob sib kis yuav tsum raug tshem tawm es tsis kho.
Q: Qib 2 puas ua raws li cov qauv cog?
Qib 2 muaj nyob rau hauv ASTM F67 rau unalloyed titanium rau kev phais implants, tab sis implant cov ntaub ntawv yuav tsum tau rau siab certification thiab traceability tshaj lub industrial raj specification.
