Muaj ntau yam super austenitic stainless hlau nyob rau hauv kev ua lag luam, nws tseem hu ua rau-molybdenum alloy hlau. Lawv cov tshuaj muaj pes tsawg leeg yog tib yam, lawv txhua tus muaj kwv yees li 20% chromium, 6.0% molybdenum thiab 0.20% nitrogen. Cov qib steel ntawm hom super austenitic stainless hlau yog: 254SMO / S31254, Cronifer 1925hMo (1.4529, N08926) thiab AL-6XN (N08367), thiab lwm yam. Niaj hnub no, "100 Thib Ob Tshwj Xeeb Steel" Qhia qhov zoo sib xws thiab kev sib txawv ntawm cov hlau tsis zoo, peb hom kev txhim kho steel hlau txawv teb chaws nkag siab los ua ib qho kev piav qhia.
1, super stainless hlau txoj kev loj hlob
Nyob rau hauv tam sim no tus qauv American (ASTM) nyob rau hauv , Peb super austenitic stainless hlau tuaj yeem pom, Saib Table 1 . ntawm , Tsuas yog 254SMO yog tsom, Txhawm rau txhim kho pitting corrosion kuj thiab crevice corrosion kuj ntawm cov ntaub ntawv, tib lub sijhawm, los xyuas kom meej lub weldability ntawm cov phaj tuab, Tsim .1978 SMO STAT xyoo kawg, factories invented thiab pib ua lag luam loj ntau lawm, Nws yog siv nyob rau hauv txawv industries qhov twg corrosive ib puag ncig yog hnyav.
AL-6XN (N08367) Nws yog tsim los ntawm nws thawj qib steel. Nws cov qauv muaj kwv yees li 20% chromium thiab 6.0% molybdenum hauv, tab sis tsis muaj nitrogen. Vim tias tsis muaj nitrogen, tsuas yog nyias steel sawb thiab nyias-walled heat exchanger tube tuaj yeem tsim tau, txwv tsis pub yuav muaj σ theem nag lossis daus, ua rau txo qhov tawv thiab corrosion kuj. muaj 0.20% Txhim kho nitrogen tau qhia rau kev lag luam thaum ntxov xyoo 1980s.
1.4529 (N08926) yog ib qho ntxiv nitrogen, rau qub 904L steel cov qauv txhim kho. Cov qauv qub kuj tsis tshua muaj nitrogen. Txog thaum nruab nrab xyoo 1980, cov ntsiab lus nitrogen yog 0.20%. Tus qauv tam sim no nyuam qhuav pib paub tab.
2, Cov qauv kev tswj hwm
Txawm hais tias tag nrho peb qib ntawm cov hlau muaj nyob rau hauv cov qauv tshiab ntawm American Standard (ASTM A240) nyob rau hauv , Tab sis tsuas yog 254SMO thiab N08926 Muaj nyob rau hauv lub tshiab executed , Pom zoo European Standards (EN) nyob rau hauv , thiab N08367 Tab sis tsis muaj , Saib Table 1 . Studies muaj ib tug moj tej yam kev mob ntawm nitrogen. txhim kho corrosion kuj ntawm stainless hlau. Table 1 qhia cov ntsiab lus ntawm cov ntsiab lus hauv peb lub superaustenitic stainless hlau. Thiab nws txoj haujlwm tuaj yeem tshwm sim hauv cov qauv hauv qab no. nruab nrab ntawm PRE Qhov loj dua tus nqi. , Qhov siab dua qhov corrosion kuj.
Formula (1):P RE=% chromium +3,3% molybdenum +16% nitrogen
3, corrosion kuj
Txhua qib steel yog tsim los rau qhov chaw corrosion thiab crevice corrosion teeb meem nyob rau hauv chloride ib puag ncig. Thiab cov qauv tsim alloy yog tib yam, uas yog: Lawv txhua tus txais yuav "20 chromium +6 molybdenum +0.2 nitrogen" txoj cai. Qhov tshwm sim yog koj PRE Cov txiaj ntsig yog tag nrho hauv 41 ~ 43 Hauv qhov ntau ntawm . Tab sis qhov sib txawv ntawm peb qib ntawm steel yog tsawg heev.
Koj tuaj yeem pom, Cov ntsiab lus ntawm txhua yam tseem ceeb tshuaj lom neeg yog ze heev. Cov nqi PRE yog nyob rau tib theem. Nws yog tsim nyog hais tias, Lub precision ntawm niaj hnub steel manufacturing yog siab heev. Nyob rau hauv lwm yam lus, nws yog ib qho yooj yim los tswj cov ntsiab lus ntawm cov nqi siab tshaj plaws ntawm tus nqi qis ntawm tus qauv (kom txo cov nqi).
Qhov sib txawv loj tshaj plaws hauv cov tshuaj muaj pes tsawg leeg ntawm peb lub super austenitic stainless hlau yog cov ntsiab lus npib tsib xee. N08926 thiab N08367 Cov ntsiab lus nickel yog 25%, thiab 254SMO tsuas yog 18%. Tab sis npib tsib xee tsis tshua muaj kev cuam tshuam rau corrosion kuj ntawm cov khoom, Saib cov mis (1).
los ntawm ASTM Raws li cov lus muaj pes tsawg leeg, Peb lub ntsiab lus no yog qhov sib txuam hauv peb lub super stainless hlau. Hauv lwm lo lus, Qhov kev tiv thaiv corrosion qhov tseem ceeb ntawm peb qhov tseem ceeb yog tib yam. "Tshwj xeeb steel 100 vib nas this" Xav, Vim qhov zoo ntawm txhua pawg ntawm CR, MO, N cov ntaub ntawv muaj qhov sib txawv ntawm cov ntsiab lus, yog li qhov tseeb corrosion kuj yuav txawv me ntsis. Tab sis feem ntau tag nrho peb yog tib theem ntawm kev tiv thaiv corrosion, lawv tuaj yeem hloov ib leeg hauv ntau qhov kev ua haujlwm.
4, Kev xaiv cov khoom siv
Kev xaiv ntawm stainless hlau yuav tsum yog nyob ntawm qhov chaw corrosive (xws li cov ntsiab lus chloride ion, pH thiab kub, thiab lwm yam) thiab cov qauv tsim ntawm lub cuab yeej. Corrosion kuj yog ib qho ntawm cov khoom tseem ceeb.
Hauv cov ntsiab lus, Tag nrho peb lub super austenitic stainless hlau muaj tib theem ntawm kev tiv thaiv chloride corrosion. Tsis tas li ntawd, muaj cov khoom siv, cov khoom specifications ntawm cov ntaub ntawv yog ib qho tseem ceeb heev. 254SMO tuaj yeem ua rau hauv daim ntawv coil. Qhov no yog rau kev tsim, txuag cov ntaub ntawv muab kev nplij siab zoo. Lub caij no, vim nws cov ntsiab lus tsis tshua muaj npib tsib xee, yog li nws tus nqi tsis tshua cuam tshuam los ntawm tus nqi ntawm npib tsib xee. Hauv kev ua lag luam hauv tsev, 254SMO tseem yuav tsum muaj kev lag luam loj tshaj plaws.
