316L vs 904L Austenitic Stainless Steels: Standard Marine-Qib vs Strong Acid Resistance

 

Dab tsi yog lawv cov ntsiab lus tseem ceeb thiab qhov sib txawv ntawm kev ua haujlwm tseem ceeb?

316L muaj 16–18% Cr, 10–14% Ni, 2–3% Mo, thiab tsawg dua lossis sib npaug li 0.03% C. Nws muaj Pitting Resistance Equivalent Number (PREN) ntawm ~ 31, muab kev tiv thaiv zoo rau dej hiav txwv thiab me me chlorides.904L nta 19–23% Cr, 4–23%, 4–23% Cr, 1–2% Cu, thiab tsawg dua los yog sib npaug rau 0.02% C. Nws cov ntsiab lus siab nickel thiab tooj liab stabilize cov zaj duab xis passive hauv kev txo cov acids xws li sulfuric acid, thaum nws PREN ntawm ~ 40 muab superior pitting resistance.Ob qib tsis yog -magnetic nyob rau hauv lub annealed lub xeev thiab muaj zoo weldability.

Lawv cov kev tiv thaiv corrosion ua li cas hauv qhov tiag - ntiaj teb ib puag ncig?

316L ua tau zoo nyob rau hauv cov huab cua hauv hiav txwv, cov dej tsis qab ntsev, thiab cov tshuaj chloride nruab nrab: zoo tagnrho rau cov nkoj fittings, tshav kub exchangers, thiab cov khoom ua zaub mov. Nws yuav corrode nyob rau hauv kub concentrated acids.904L dominates tshuaj ua ib puag ncig: sulfuric acid nroj tsuag, phosphoric acid ntau lawm, thiab pulp bleaching. Nws tiv taus kev ntxhov siab corrosion (SCC) zoo dua 316L hauv chloride-muaj cov kua qaub.

Nyob rau hauv daim ntawv thov twg yog ib qib irreplaceable dua lwm?

Xaiv 316L rau cov txheej txheem marine, ntug hiav txwv dej, thiab qis -acid industrial applications qhov twg tus nqi yog qhov tseem ceeb.Kev xaiv rau 904L rau cov cuab yeej tuav sulfuric acid, acetic acid, lossis cov tshuaj lom neeg sib xyaw uas 316L yuav ua tsis tau sai.

Tus nqi thiab kev tsim khoom lag luam yog dab tsi- tawm ntawm ob qib?

904L raug nqi ntau dua (feem ntau 2-3 zaug) ntau dua 316L vim nws cov ntsiab lus nickel thiab molybdenum siab.316L yog yooj yim thiab yooj yim rau fabricate nrog cov qauv txheem.904L yuav tsum tau qis-kub input welding (GTAW) thiab sib piv siab -nickel muab tub lim hlau nws muaj zog corrosion (xws li Mo-4EN); Nws kuj yog nquag ua hauj lwm hardening thaum lub sij hawm machining.

Cov kev txwv tseem ceeb thiab cov txheej txheem xaiv yog dab tsi?

316L tsis haum rau cov kua qaub uas muaj zog lossis siab -cov tshuaj chloride kub.904L dhau lawm- tau teev tseg rau kev siv marine txheem; tus nqi ntxiv tsis muab cov txiaj ntsig tseem ceeb hauv dej hiav txwv ib leeg.