Titanium Welded Hlawv

Titanium lub ntom yog li 60% uas ntawm stainless hlau thiab nickel alloys, qhov hnyav no txuag ua rau nws xaiv qhov chaw zoo uas yog qhov tseem ceeb xws li aerospace.

ASTM A240 Hom 2205 Phaj yog lub Duplex phaj yog siv ntau yam kev lag luam xws li kev ua yeeb yam, roj thiab roj kev tshawb nrhiav, thiab marine engineering. Sa 240 gr 2205 daim ntawv yog tsim los ntawm qib 220) stainless hlau, uas yog kev sib xyaw ntawm ferritic thiab ustenitic steel.

Inconel 718 yog npib tsib xee-chromium-based alloy uas feem ntau siv nyob rau hauv cov ntawv thov kub siab xws li aerospace thiab roj turbines. Ib qho ntawm cov tseem ceeb tshaj plaws hauv kev tsim cov astm b670 inconel 718 daim ntawv yog lub phaj dov. Muaj ob hom tseem ceeb ntawm inconel 718 daim hlau muaj nyob rau ntawm kev ua lag luam: kub dov thiab cov phiaj txias. Cov paib.

316L 1.4401 tus yeeb nkab stainless hlau yog ib qho kev xaiv yeeb nkab zoo heev thiab cov yeeb nkab ruaj khov siv hauv ntau cov ntawv siv. Qhov no ss s31603 yeeb nkab yog tsim los ntawm cov hlau zoo 316L stainless ua rau corrosion, oxidation thiab staining rau cov chaw hnyav lossis kev siv ntxhov siab.

Inconel 625 coil yog cov yam ntxwv zoo los ntawm nws cov kev tiv thaiv zoo rau oxidation, qhov siab-kub corrosion thiab qaug zog. ASTM B443 tsis yog N06625 Inconel P phaj tau siv dav hauv Aerospace, kev ua lag luam thiab roj thiab muaj zog zoo dua qub txawm tias muaj ib puag ncig zoo.

Alloy 800 yog npib npib tsib xee-chromium alloy nrog siab zog thiab kev tiv thaiv zoo rau oxidation thiab corrosion ntawm qhov kub. ASTM B407 UNICS NC08800 INCOLOY 800 W. NR. 1.4876 Welded yeeb nkab yog dav siv rau kev tsim kho cov khoom siv uas yuav tsum tau ua rau corrosion tsis kam, lub zog, thiab ruaj khov rau kev pabcuam txog 1500 ° F (816 ° C).

Lub 316 cov yeeb nkab stainless hlau tau dhau los ua cov khoom siv tsis tau rau cov kev lag luam lag luam. Qhov no alloy ntawm hlau thiab chrome tau lees paub rau nws lub siab tiv taus corrosion, nrog rau nws cov kav ntev. 316 Stainless hlau Tubing tuaj yeem tsim nyob rau hauv ob leeg seamless thiab welded leeg kom tau raws li cov neeg siv khoom xav tau.

Hastelloy C2000 tub tshij yog siv nyob rau hauv ntau hom petrochemical suav nrog cov khoom siv tshuaj lom neeg, roj kev tsim khoom siv, roj ntxiv thiab cov nroj tsuag hluav taws xob.

Hastelloy C2000 muaj nyob rau ntau qhov ntau thiab tsawg, hom no-lickel-molybdenum alloy muaj zog thiab corrosion tsis kam.

Al6XN yog superaustenitic steel hlau nrog kev ua tau zoo rau chloride pitting, crevice corrosion thiab kev nyuaj siab corrosion tawg. Al6XN yog 6 Moly alloy uas tau tsim rau thiab siv hauv kev sib cav sib ceg siab. Nws muaj cov npib tsib xee (24%), Molybdenum (6.3%), nitriumen thiab chromium cov ntsiab lus tawg, thiab tshwj xeeb corrosion tiv thaiv. Al6XN yog feem ntau siv rau nws cov kev txhim kho pitting thiab crevice corrosion tsis kam hauv chlorides. Nws yog ib qho tsim nyog thiab weldable stainless hlau.

Tsis suav txog N08367 tseem hu ua Alloy Al6XN yog cov carbon ntau, siab purity, nitrogen-batoy nrog zoo heev rau chloride pitting thiab compevice corrosion.

SMO 254 Cov kav dej tuaj yeem tiv taus cov kev ntxhov siab ntawm cov neeg muaj kev ntxhov siab thiab alloy 254 smo yeeb nkab siab ua haujlwm nyob rau hauv cov kub thiab xeb ib puag ncig.

Qhov no muab kev txhim kho zoo heev rau cov sulfuric acid. Nws kuj tseem muaj cov ntsiab lus chromium siab, kom ua kom zoo dua rau oxidizing tshuaj lom neeg cov tshuaj lom kabmob uas muaj kuab lom thiab yaj oxygen.

Nws muaj peev xwm tiv thaiv ntau yam ntawm oxidizing thiab tsis-oxidizing tshuaj, thiab cov khoom ua kom pom tseeb zoo rau pitting thiab crevice nres nyob rau hauv muaj cov chlorides thiab lwm yam.

Nws ua rau pom zoo tsis kam mus rau nruab nrab thiab txo qhov chaw. Cov alloy no tsim ib zaj yeeb yaj kiab oxide, kev tiv thaiv zaj duab xis uas tsis tawm mus, tab sis nws khaws cov oxidation superi-sauv tsis kub.

Nws yog dav siv nyob rau hauv cov roj pov thiab roj kev tshawb nrhiav \ / ntau lawm thiab hauv kev hloov cua sov hauv petrochemical \ / tshuaj lom neeg.

Inconel 600 Seamless Tubes ntawm cov qauv tsis ua N06600 thiab ASTM B167 yog cov uas tsim kom muaj kev tiv thaiv ntau dhau kev tiv thaiv dhau los.

SCH40 monel 400 yeeb nkab raug xaiv raws li Werkstoff tus lej 2.4360 thiab tsis yog N04400. Alloy 400 cov kav hlau tseem hu ua monel aleloy 400 Yeeb Nkab, Monel 400 Yeeb & Nickel Alloy 400 Yeeb Nkab.

Cov kav dej ntawm seamless configurations tau muaj peev xwm ntau dua cov muaj peev xwm thiab lub zog tshaj lwm qib.

Siab chromium, molybdenum thiab nitrogen cov ntsiab lus cuam tshuam nrog pitting tsis zoo rau cov medtenatent thiab corrosive corrosive conduction, thiab tseem ceeb pitting txias rau tag nrho cov xov xwm, thiab tseem ceeb pitting txias rau saum 50¡Ãc.

Hastelloy alloys phau ntawv qhia
Lub corrosion resistant Hastelloy alloys tau siv dav los ntawm kev lag luam ua lag luam. Qhov kev xav tau rau kev ua tau zoo ua rau lawv txoj kev lees paub thiab kev loj hlob hauv thaj chaw ntawm lub zog, kev noj qab haus huv thiab ib puag ncig, roj thiab cov roj thiab cov roj cuv khw desulfurization.

Incoloy 800H Flange Peb muaj lub koob npe nrov hauv kev lag luam rau kev tsim cov hom kev ua haujlwm zoo ntawm cov hom uas yuav tsum tau ua rau peb cov neeg siv khoom. Peb tsim khoom tsim prololoy 800 flanges uas muaj kev ntseeg siab thiab siab dua. Peb siv cov peev txheej hwm thiab qib siab tshaj tawm rau kev tsim ASTM B564 UNFANCES 800 flanges.

Alloy 800 Weld Neck Flanges Peb muaj lub koob npe nrov hauv kev lag luam rau kev tsim cov hom kev ua haujlwm zoo uas yuav haum rau peb cov neeg siv khoom. Peb tsim khoom tsim prololoy 800 flanges uas muaj kev ntseeg siab thiab siab dua. Peb siv cov peev txheej hwm thiab qib siab tshaj tawm rau kev tsim ASTM B564 UNFANCES 800 flanges.

Nickel 200 flanges lub npib tsib xee 200 flanges yog ruaj, tshuav ruaj khov, thiab muaj kev ua tiav zoo. Ntxiv mus, cov ASTM B564 tsis pom N02200 dig muag flanges tiv taus ib puag ncig hauv nruab nrab thiab oxidizing ib puag ncig, ua rau lawv zoo meej rau kev siv hauv cov khoom siv khoom noj khoom haus.

Lwm qhov tseem ceeb ntawm N08800 Incoloy alloy 800 lub phaj txias rolled ntsig txog corrosion, zoo li cov hlau, zoo li nws cov coungon counterparts yog kev tiv thaiv kab mob rau.
Hom Phaj, Ntawv, Sawb Chev
Ntev 0 ~ 12m lossis raws li koj xav tau
Dav 0 ~ 2500 hli lossis raws li koj xav tau
Thickness 0.3 ~ 1200mm lossis raws li koj xav tau

Inconel 600 yog npib tsib xee-chromium-hlau alloy nrog zoo heev corrosion, oxidation tsis kam thiab siab lub zog ntawm kev nce siab kub. Vim nws cov ntsiab lus nickel siab, inconel 600 yog tsis tshua muaj resistant rau chloride ion muaj kev ntxhov siab corrosion. Hnub nyoog tawv yog tsis tas yuav ua tsis tau li 600 yog qhov tawv thiab muaj zog los ntawm kev ua haujlwm txias nkaus xwb. Qhov Inconel 600 tuaj yeem ua haujlwm hauv qhov kub thiab txias li 700¡Ãf (370¡Ã).
Txheem sus, AISI, DIN
Inch 5 ~ 500 hli
Ntev ¨Q12m lossis raws li cov neeg xav tau

Cov kab ke sib txuas yog txias txias thiab anealed, muaj nyob rau hauv Tshuag ntev lossis txiav kom loj. Alloy puag ncig cov kab muab lub zog thiab corrosion tsis kam nyob rau ntau thaj chaw, tshuab sib tsim khoom, kev lag luam kho khoom noj thiab kev lag luam kho mob.
Txheem sus, AISI, DIN
Inch 5 ~ 500 hli
Ntev ¨Q12m lossis raws li cov neeg xav tau

Ntau cov lag luam nyiam qhov tseeb uas Inconel 600 yog ib qho ntau yam. Yog li ntawd cov alloy yog siv nyob rau hauv ob peb cov ntaub ntawv tseem ceeb hauv ntau hom ntawv suav nrog qhov nrov tsis sib xws 600 cov yeeb nkab. Kev tsim kho ntawm cov kav dej no tuaj yeem welded lossis lawv tuaj yeem yog seamless. Muaj cov txiaj ntsig siv ob qho tib si. Rau e.g. Qhov kev nyiam ntawm ib qho kev hloov kho 600 Welded yeeb nkab, yog nyob rau hauv cov ntawv thov uas nws lag luam ua haujlwm tseem ceeb heev. Txawm hais tias pheej yig dua li cov noob tsis muaj zog tsim ib qho, cov kav dej no muaj cov kab sib tw ntev, uas tuaj yeem ua rau muaj kev cuam tshuam nrog kev txhim kho corrosion - yog tias lawv tsis raug. Hauv ib qho xwm txheej, uas tus neeg yuav khoom yuav tsum tau muaj qhov siab tshaj plaws ntawm corrosion tsis kam thiab muaj peev xwm tiv taus qhov siab dua, tsis haum 600 seamless yeeb nkab yog qhov kev xaiv zoo tshaj plaws.
Ntaus Seamless Yeeb Nkab
Lub raj seamless
Welded Yeeb Nkab
Welded Tube
Pom lsaw erw EFW
Beveled kawg, ntshiab kawg "
Loj od: 1 \ / 2 "" ~ 48 ""
Thickness: Sch5 ~ Schxxs
Ntev: Raws li qhov koj xav tau. "
Tsim cov txheej txheem kub dov rolling \ / kub ua hauj lwm, dov
Tsim cov qauv ASME B36.10 ASME B36.20

Rau cov hom phiaj muaj, hauv cov raj hluav taws xob, peb feem ntau yuav tsum tau hloov cov kev coj ntawm kev xa khoom; tswj cov dej ntws (roj thiab roj, dej, av); Qhib lossis kaw cov raj xa dej, thiab lwm yam, kom ua tiav cov haujlwm no, cov yeeb nkab txheem yeeb nkab, cov yeeb nkab steel fittings yuav raug siv.

Npib tsib xee raws 800 incoloy hexagonal yeeb nkab yog paub kom muaj qhov zoo tiv taus corrosion. Tshwj xeeb hais txog kev hais lus, tus incoloy 800 yeeb nkab muaj txaus tiv taus ob carburization zoo li oxidation corrosion.

Carbon Steel Flange yog hom Rim tsim thaum kawg ntawm cov yeeb nkab thaum nws tsau rau ntawm cov yeeb nkab. Nws yog siv los txiav qhov xaus ntawm cov kav dej, li qub lossis lwm yam sib txuas. Nws muaj lub zog siab tensile thiab muaj nrog convex nto thiab txhawb kom yooj yim installation. Nws yog cov hlau-carbon alloy muaj txog li 2.1 wt.% Carbon. Cov pa roj carbon hlau tsis muaj cov theem tsawg kawg ntawm lwm cov khoom siv, tab sis nws feem ntau muaj cov manganese.

Cov khoom siv S32205 DuPlex Asme asme sa182 pob tw Weld Flanges yog tsim nyog rau dej hiav txwv thiab cov khoom siv hluav taws xob tuaj yeem tiv thaiv kom sov txog 600,000Ãf, thaum tseem muaj cov yam ntxwv zoo.

Hastelloy C-276 yog ni mo Cr Superalloy ntxiv nrog tungsten, uas muaj kev tiv thaiv corrosion tsis kam nyob rau hauv ib puag ncig hnyav. Cov ntsiab lus siab ntawm ni thiab mo ua rau ni steel alloy tshwj xeeb tiv taus pitting thiab crevice corrosion hauv kev txo qhov kev ua tau zoo ntawm kev tiv thaiv oxidation.

Txawm hais tias Molybdenum yog lub caij zoo, kev siv ntau dhau ntawm nws yuav txo cov txheej txheem creep ntawm gr11 phaj flanges. Gracitizitization thiab decomposition ntawm hlau carbide yuav tshwm sim thaum qhov kub tshaj 500 degrees Celsius. Chromium tau ntxiv rau SA A182 F11 Alloy Alloy Steel Cl.2 Flanges tiv thaiv kom tiv thaiv kev nkag mus thiab teeb meem creep. Tsis tas li ntawd, cov chromium ntxiv tseem muab oxidation tiv taus.

DupleX Steel Flanges tau siv dav hauv kev siv tshuab siv, kev lag luam tshuab thiab tsheb lag luam hauv tsheb. Duplex steel s31803 lap flanges yog qhov zoo tagnrho rau cov ntawv thov ua kom zoo dua li hom 316 thiab lub zog kub zoo. Peb muaj lub duplex steel s31803 \ / s32205 flanges hauv Tshuag. Duplex steel flanges yog ib txwm siv hauv tshuaj, petrochemical, thiab kev lag luam fais fab.

Nickel 200 yog cov khoom siv hluav taws xob txuag hluav taws xob. Nickel 200 Bar Tshuag muaj 99.6% Wrought Nickel los ntawm qhov hnyav thiab yog suav hais tias muaj kev lag luam npib tsib xee. DIN 2.4066 bar muaj cov khoom siv zoo thiab lub cev. Piv txwv li, ASTM B160 n02200 tau ua tau zoo heev rau ntau cov corrosive tebchaw nrog rau kev xeb ib puag ncig. Lub caij no, Nickel 200 yog cov khoom siv hluav taws xob muaj zog wrought wrouging alloy uas tuaj yeem tsim los ua cov kab tuav thiab pas nrig. Cov ob feem xyuam no tau siv sib hloov pauv thiab tuaj yeem txawv ntawm qee lub luag haujlwm tseem ceeb.

Nickel-Tooj-based alloy 400 monel 2.4360 txias kos cov kab mob kev ntxhov siab thaum raug rau corrosive cracking thaum raug rau cov media corrosive nyob rau hauv ib puag ncig ib puag ncig. Monel 400 yog tooj liab thiab nickel raws li alloy uas nrov niaj hnub no vim nws qhov kev ua tau zoo. Lub alloy muaj kua qaub zoo heev thiab alkali tsis kam. Tsis tas li ntawd, nws muaj cov zog tensile muaj zog, ductility, zoo heev thermal condactivity, thiab tuaj yeem yog tawv los ntawm kev ua haujlwm txias. Ib qho ntxiv, nws tuaj yeem siv rau hauv cov ntawv thov nrog qhov kub thiab txias txij li rho tawm txog 538 degrees Celsius.

Nickel alloy 400 thiab Monel 400, tseem hu ua UN tsis zoo li N04400, yog ib qho laj thawj ntawm cov menyuam yaus uas muaj feem ntau ntawm ob feem peb ntawm ob feem ntawm ob-tus tooj liab. Nickel Alloy 400 yog paub txog nws txoj kev tiv thaiv rau ntau yam ntawm cov kab mob ntawm cov xeb, suav nrog cov alkalis (lossis cov kua qaub), dej hli, thiab sulfuric acid. Txij li thaum Monel 400 lossis Alloy 400 yog cov hlau txias ua haujlwm, cov alloy muaj siab tawv, txhav thiab muaj zog. Los ntawm kev ua haujlwm txias ASTM B14400 Bar Tshuag, cov alloy yog raug rau cov kev ntxhov siab ntau dua, uas nyob rau hauv Alloy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Microy Micro ..

Inconel 600 puag ncig bar yog npib tsib xee-raws li benign carburization thiab zoo heev corrosion thiab kub heev. Inconel 600 cov khoom sib txuas ua haujlwm tiv thaiv kom qhuav cl2 thiab ntau lwm cov roj sib txawv ntawm cov mob me thiab kub. Alloy 600 Bar yog npib tsib xee-chromium alloy nrog zoo oxoidation decomposition decomposition decomposition thiab acid oxidation ntawm ntug dej kub.

Nilo \ / alloy k w.nr.: 1.3981
UNRENT: K94610 ASTM F15
Tsau-nthuav dav iav-encapsulated girapsulated alloys, muaj ib qho kev nthuav dav thermal, muaj ib lub khob hluav taws xob nthuav dav zoo ib yam li qhov ntsuas kub
Rau mating sealing nrog cov iav nyuaj

Nilo Alloy 36, W.NR 1.3912, Tiv Thaiv 36% Nickel-Npib thiab muaj tus nqi ntawm kev nthuav dav ntawm cov hlau.
Caw 36 Cov Lus Qhia Tshwj Xeeb: tsis yog K93600, W.NR 1.3912

Cov npe lag luam sib xws: Nickel Alloy 36®, Nilo 6®, Pernifer 6®
Caw 36 ® yog npib npib npib tsib xee, tsis muaj nyiaj npib ob leeg uas muaj 36%, commar 36 muaj qhov kub tsawg los ntawm kev nthuav dav ntawm + 500 ° F (260 ° C).
Invar 36 Tube OD: 0.2-6mm, wt: 0.02-2mm

Flange yog cov seem uas txuas ob qho yeeb nkab xaus, flange kev sib txuas tau txhais los ntawm cov flange, gasket thiab bolt peb sib txuas ntawm cov kev sib txuas ntawm lub kaw. Lub gasket yog ntxiv ntawm ob lub pluaj ib qho thiab tom qab ntawd nrawm los ntawm bolts. Cov tawv nqaij txawv flange, tuab yog qhov sib txawv, thiab cov khoom sib txuas tau sib txuas, xws li kev sib txuas ntawm Flange thiab cov twj tso kua mis, nws tsis yog inapposite rau Hu rau dej twj tso kua dej raws li Flange hom, tab sis txheeb ze lub valve me me, nws tuaj yeem hu ua Flange hom.

Nyob ntawm daim ntawv thov no tshwj xeeb tuaj yeem ua titanium thiab titanium alloys ib qho kev xaiv tsim nyog dua li cov hlau tsis muaj txiaj ntsig thiab cov nickel alloys.

Nws lub zog tensile siab kuj txhais tau tias txo cov txheej txheej phab ntsa tuaj yeem siv tau hauv cov ntawv thov, thiab cov khoom txuag no txhais tau tias txo qis dua lossis txo qhov hnyav ntxiv.

Titanium yog cov corrosion heev uas ua rau nws xaiv zoo nyob qhov twg muaj zog thiab corrosion tsis kam yog qhov tseem ceeb.

Titanium yog tsis muaj kev sib nqus, muaj ntau dua marting taw tes ntau dua li cov khoom siv cua sov thiab cov khoom cua kub txhais tau tias nws yog siv hauv kev sib pauv cov txheej txheem kub.

Txawm hais tias nws lub zog, titanium yog yooj yim ua haujlwm. Qhov no cov cwj pwm ua ke nrog nws lub zog, nruj, kev nruj thiab zoo melting taw tes ua nws cov hlau tsim nyog heev rau kev ua haujlwm zoo tubing.

Titanium yeeb nkab yog ib nrab ntawm qhov hnyav ntawm cov hlau, tias nws muaj qhov qis dua, nws tuaj yeem yog qhov muaj zog (li hlau) ntawm ib nrab qhov hnyav.

Tsawg lub cev nyhav sib txuas nrog lub zog siab heev tso cai rau kev siv txawm tias cov khoom siv rho tawm, ua kom lub cev tso tawm ntawm cov khoom siv hluav taws xob zoo heev thiab tiv taus tib lub sijhawm.

Seamless titanium yeeb nkab yog tus cwj pwm los ntawm nws lub zog siab rau qhov hnyav piv. Nws yog qhov tseem ceeb heev nyob rau hauv ib qho oxygen dawb ib puag ncig thiab muaj qhov ntom ntom tsawg.?

Cov khoom siv tau zoo heev yoog thiab tuaj yeem welded zoo heev.

Titanium Micro Raj? Yog lub teeb ci ntsa iab thiab muaj zog ua rau lawv zoo tagnrho rau aerospace, tsheb, tub rog thiab kev siv tub rog thiab kev lag luam.

Cov ntawv thov raug yog corrosion resistant hauv kev lag luam tshuaj, tubrog nkoj, kev tsim kho kho tsheb thiab kev tsim kho thiab lub siab tau txais txiaj ntsig thiab muaj txiaj ntsig.

Titanium Welded Yeeb Nkab? Muaj qhov taw tes zoo heev uas yog ntau dua 1650 degrees centigrade lossis 3000 degrees Fahrenheit.

Titanium muaj koob meej rau nws lub zog, tsis tshua muaj zog hauv kev sib piv nrog cov hlau thiab nws corrosion tsis kam. Cov kev ua tau zoo ua rau nws xaiv nrov nyob hauv ntau yam kev lag luam.

Titanium ERW cov yeeb nkab muaj nqi piv rau txhuas.

Ntshiab seamless titanium yeeb tau ob npaug lub zog ntawm txhuas &? Titanium ASTM B338 yeeb nkab?

ASTM B338 titanium boiler raj yog suav hais tias yog ib qho ntawm cov hlau uas muaj zog tshaj plaws.

ASME SB338 Titanium Hloov Yeeb Yeeb Nkab yog lub zog thiab lub teeb ci ua rau lawv zoo tagnrho rau aerospace, tsheb, tub rog thiab kev siv tub rog thiab kev lag luam.

Ntshiab titanium sb338 steel yeeb nkab muaj zog thiab corrosive resistant.

Titanium NCF Tube yog cov xim muaj xim zoo nkauj nrog lub zog siab thiab ntom ntom.

Titanium Scch 40 yeeb nkab muaj cov cim tshuaj lom TI & tseem hu ua Ti Clad kav. Titanium txhuam cov yeeb nkab yog paramagnetic alloy.

Titanium Square Yeeb Nkab yog cov xim pleev xim nrog cov hlau siab thiab lub zog qis.

Ntshiab titanium condenser raj yog xeb resistant thiab muaj zog.

Peb yog tus kws tshaj lij nyob rau hauv? Titanium chev tubing? & Peb kuj tswj cov raj me me titanium boile?

Qhov no zoo tagnrho rau kev siv hauv kev tso pa, tab sis kuj yog li roj, dej txias lossis roj roj.

Ua tsaug rau nws cov khoom tshwj xeeb, titanium yog cov khoom siv zoo tshaj plaws rau kev tsim kom muaj pa ntawm kev ua kis las hauv lub cev muaj zog.