Kev ceeb toom dav dav: Tsis yog txhua tus tooj dag muaj kev nyab xeeb
Cov qauv kev lag luam tooj dag fittings feem ntau tsis muaj kev nyab xeeb rau kev siv ntev hauv cov dej hiav txwv lossis dej ntsev. Qhov laj thawj tseem ceeb yog ib hom kev xeb hu ua dezincification, uas yog aggressively accelerated los ntawm chlorides pom nyob rau hauv seawater.
Cov txheej txheem dezincification hauv dej ntsev
Dezincification yog ib qho tshuaj tiv thaiv uas cov zinc tivthaiv ntawm cov hlau leaches tawm. Nyob rau hauv dej ntsev, nrog nws cov chloride ion concentration siab, tus nqi ntawm zinc dissolution nce, tshwj xeeb tshaj yog nyob rau hauv sov tej yam kev mob. Qhov seem yog qhov tsis muaj zog, ntxeem tau, thiab spongy tooj liab qauv.
Kev poob loj heev hauv dej ntsev
Qhov kev pheej hmoo ntawm kev ua tsis tiav yog qhov tseem ceeb hauv cov dej hiav txwv sov. Cov kev tshawb fawb tshuaj tau sau tseg tias hauv 16% sodium chloride (NaCl) tov ntawm qhov kub ntawm 60℃txog 80 degree, dezincification yog qhov hnyav. Cov ntsiab lus tooj liab ntawm cov hlau nplaum saum npoo tau nce mus rau 98%, txhais tau tias cov txheej txheem zinc tau ploj mus, tawm hauv qhov haum tsis tshua muaj nkig.
Txoj Kev Pom Zoo: DZR Brass
Rau kev nyab xeeb marine siv, koj yuav tsum sivDZR Brass(Dezincification Resistant Brass), tseem hu ua CR (Corrosion Resistant) tooj dag. Cov neeg tsim khoom tshwj xeeb tsim cov khoom siv tawv nqaij thiab lwm yam khoom siv los ntawm DZR tooj dag, qhia meej meej tias lawv tsim nyog rau kev raug dej hiav txwv. Cov hlau no muaj cov khoom ntxiv xws li tin lossis arsenic los tiv thaiv zinc leaching.
Bronze vs. Brass hauv Galvanic Corrosion
Kev nyab xeeb nyob ntawm kev ua kom tag nrho "wetted" sib dhos zoo ib yam. Ib qho kev pheej hmoo paub yog galvanic corrosion ntawm tooj dag thiab tooj liab alloys. Qhov sib txawv ntawm kev ua nom ua tswv ntawm ob lub hlau hauv cov khoom siv hluav taws xob (cov dej ntsev) tsim cov roj teeb, ua rau kom tsis muaj zog ntawm cov khoom siv tsis zoo ( tooj dag).
Kev Qhia Txog Kev Ua Tubrog Nkoj
Qhov no tsis yog me ntsis technicality. Cov khw muag khoom hauv hiav txwv loj yuav tsis muag cov khoom siv tooj dag rau cov khoom siv los ntawm - cov ntawv thov hull. Lawv ceeb toom meej meej tias vim muaj kev pheej hmoo ntawm galvanic corrosion, lawv "hais kom koj tsis txhob siv cov alloys ua ke nyob rau hauv dej ntsev ib puag ncig" thiab es tsis txhob hais cam khwb cia tooj liab los yog tshwj xeeb yas xws li Marelon® .
Saum toj no - Dej vs. Hauv qab -Kev Siv Dej
Qhov chaw txiav txim siab qhov hnyav ntawm qhov kev pheej hmoo. Cov khoom siv tooj dag yog qee zaum siv tau rau saum toj no - siv cov kav dej, xws li ntawm lub lawj rails lossis qhov cua, qhov uas lawv tsis tas mus rau hauv dej. Txawm li cas los xij, rau ib qho dej hauv qab los yog dhau los ntawm - lub nkoj haum, tus qauv tooj dag tsis muaj kev nyab xeeb thiab yuav ua tsis tiav.
Tshawb nrhiav ntawm Atmospheric Exposure
Txawm nyob sab nraum dej, marine cua yog corrosive. Kev tshawb fawb ntawm tooj liab alloys raug rau marine atmospheres qhia tau hais tias tus nqi corrosion nyob rau hauv marine huab cua (0.6 mus rau 1.1 µm ib xyoo) yog siab tshaj nyob rau hauv cov huab cua nyob deb nroog (0.2 mus rau 0.6 µm ib xyoo). Nyob rau lub sijhawm ntev, txawm tias "dezincification ntawm tooj dag yog qhov tseem ceeb" hauv cov huab cua hauv hiav txwv.
Plating thiab coatings tsis yog ib qho kev daws teeb meem
Txawm hais tias qee qhov tooj dag fittings npaj rau "sab nraum zoov" vaj lossis dej tshiab siv chrome lossis npib tsib xee plating los tiv thaiv tarnish, qhov no tsis yog kev daws rau dej ntsev. Ib txheej tsuas yog ib ntus thaiv; ib zaug khawb, lub hauv paus tooj dag yuav dezincify sai heev nyob rau hauv ib puag ncig marine.
Tin Brass thiab Lub luag haujlwm tshwj xeeb ntawm Tin
Qee cov tooj liab alloys muaj tin. Cov kev tshawb fawb tau tshuaj xyuas Cu-30Zn-1Sn (tin tooj dag) rau corrosion kuj. Interestingly, lub tin-nplua nuj theem nyob rau hauv lub alloy lub grain ciam teb twb tsis tawm tsam vim yog tsim ntawm tin dioxide (SnO₂). Txawm li cas los xij, lub hauv paus alpha ( ) theem matrix ntawm qhov haum tseem muaj kev nyiam corrosion thiab tooj liab redeposition .
Mechanical Strength and Wear Factors
Thaum bronze tseem ceeb heev thiab tiv taus hnav dua li tooj dag, qhov kev pheej hmoo tseem ceeb hauv kev siv dej hiav txwv tsis yog kev sib txhuam ntawm lub cev tab sis electrochemical tsis ua hauj lwm. Lub zog siab dua ntawm tooj liab ua rau nws haum rau siab - qhov kev ntxhov siab xws li cov kiv cua , tab sis rau cov khoom siv zoo li qub, qhov tseem ceeb tseem ceeb ntawm kev tiv thaiv corrosion.
ASTM Standards thiab Material Specifications
Rau kev nyab xeeb, manufacturers thiab engineers cia siab rau cov qauv alloy tshwj xeeb. Marine- qib bronze feem ntau ua tau raws li ASTM B-61 lossis B-62 cov kev cai tshwj xeeb rau kev xav tau siab ntawm dej hiav txwv. Yog hais tias lub tooj dag haum tsis muaj qhov tshwj xeeb "Marine" lossis "DZR", nws yuav tsum tau hloov nrog cov tooj liab zoo lossis cov khoom sib xyaw pom zoo siv rau hauv cov dej ntsev.
Cov ntsiab lus
Brass yeeb nkab fittingsfeem ntau tsis muaj kev nyab xeeb rau thaj chaw marine tshwj tsis yog lawv tau sau npe tshwj xeeb DZR (Dezincification Resistant). Tus qauv tooj dag fittings yuav raug kev txom nyem sai sai thiab galvanic corrosion thaum raug dej ntsev.
Rau ib qho hauv qab no - daim ntawv thov dej hiav txwv, lossis qhov chaw muaj kev nyab xeeb yog qhov tseem ceeb, siv cov cam khwb cia tooj liab fittings (uas yog keeb kwm pov thawj rau dej hiav txwv) los yog pom zoo tsis yog - metallic composites . Nco ntsoov xyuas DZR lossis CR (Corrosion Resistant) cov cim thiab tsis txhob muab cov tooj liab thiab tooj liab sib xyaw rau hauv tib qhov dej ntsev.
