corrosion - eurosteel
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w w w . e u r o s t e e l . c o . z a
Stainless Steel • Alluminium • Special Alloys
Sheet Plate Coil Tread Plate Bar Sections Extrusions Pipe Fittings FlangesPage 13
Corrosion
Media
Utility Ferritics Cr - Ni Austenitics Cr - Ni - Mo Austenitics Duplex
20ºC 60ºC 100ºC 20ºC 60ºC 100ºC 20ºC 60ºC 100ºC 20ºC 60ºC 100ºC
AldyhydesAcetic Acid (10%)Acetic Acid (glacial & anhydrous)Acetic AnhydrideAcetyleAlcoholsAlphatic EstersAlkyl ChloridesAlumAmmoniaAmyl AcetateAnilineAntimony TrichlorideAromatic SolventsAtmospheric: IndustrialAtmospheric: MarineAtmospheric: RuralAscorbic AcidBenzoic AcidBoric AcidBrines, SaturatedBromide (gaseous)Bromide (aqueous)Butyl AcetateCalcium ChlorideCarbon DisulphideCarbonic AcidCarbon TetrachlorideCaustic Soda & PotashCellulose PaintChlorates of Na, K, BaChlorine, dryChlorine, wetChlorides of Na, K, Mg, Ca, Ni, NH4, Al, Sn, ZnChlorosulphonic AcidChromic Acid (80%)Citric AcidCresylic Acids (50%)Detergents, syntheticEmulsifiers (all concentrations)Esters & EthersFatty Acids (> C6)Ferric ChlorideFluorinated Refrigerants, Aerosols, eg. FreonFluoride, dryFormic AcidFruit JuicesGelatineGlycolHydrobromic Acid (50%)Hydrochloric Acid (10%)Hydrocloric Acid (concentrated)Hydrocyanic AcidHydrofluoric AcidHydrogen Peroxide (30%)Hydrogen SulphideHydrochlorite (Na 12 - 14%)KetonesLactic Acid (100%)Lead AcetateLead PerchlorateLime (CaO)Manganate, Potassium (K)Meat JuicesMercuric ChlorideMilk & Milk ProductsMolassesMonoethanalamine
R1
RNDR2
NRRRR5
NDRRRNRRR7
R7
R7
R1
RRNRNRNRRNRRRRNDRNDNDNRR5
NDNRNRRRNDRRNRR5
NDNRR12
R1
RNRNRNRRNRRR5
R14
RNRRNRRR6
R7
NRRRR
R1
RNDNRNRRNDNDNDRRRNRRNDNDNDNDRRNRNRNRRNRRR9
RR6
RNDNDNRNRNDNRNRRRNDRRNRRNDNRNRR1
RNRNRNRNDNRRR5
NDNDNRRNRRNDNRNRNRRR
R1
NDNDNDNRRNDNDNDRRRNRRNDNDNDNDRRNRNRNRRNRRNRRR6
RNDNDNRNRNDNRNRRRNDRRNRNRNDNRNRNDRNRNRNRNDNRNDR5
NDNDNRR6
NRRNDNRNRNRRR
R1
RRR2
R3
RRR5
RRRRR5
RR7
R7
RR1
RRR8
R9
NRRNRRRRRRR1
RNRR10
NRNRR6
RRRRRNRR5
RRR12
R1
RNRNRNRRNRRR5
R14
RRRR1
RRRNRRRR
R1
RRNRR3
RRR5R6
RRRNRRNDNDNDR1
RRNRNRNRRNRRRRRRR1
RNRNRNRNRR6
RRRRRNRRNDNRRRRNRNRNRRNRRR5
NRRNRRR1
RRRNRRRR
R1
RNDNRR3
RRR5
NRRRRNRRNDNDNDR1
RRNRNRNRRNRNDRRR6
RR1
RNRNRNRNRR6
RRRRRNRRNDNRRRRNDNRNRNDNRRR5
NRRNRRR1
RRNDNRRRR
R1
RRRR3
RRR5
RRRRR5
RRRRRRRR8
R9
NRRR8
RRRRRR1
RNRR9
R10
NRRRRRRRNRR5
RRRR1
RNRNRNRRNRRR5
R14
RRRRRRRNRRRR
R1
RRRR3
RRR5
R1
RRRR5
RNDNDNDRRRNRR9
NRRNRRRRRRR1
RNRR11
NRNRRRRRRRNRRNDRRRRNRNRNRRNRRR5
NRRRRR1
RRRNRRRR
R1
RRNRR3
RRR5
NRRRRNRRNDNDNDRRRNRR9
NRRNRNDRRR6
RR1
RNRR11
NRNRR6
RRRRRNRRNDNDRRRNDNRNRNDNRRR5
NDRNRRNDRRNDNRRRR
R1
RRRR4
RRRRRRRRRRRRRRRRRNRRR10
RRRR6
RRRNRRNDNRRRRRRRNRRRRRRRNRNRNRRNRRR5
R14
RRRNDRRRRRRR
R1
RRRNRRRRRRRRRRNDNDNDRRRRNDNRRR10
RRRR6
RRRNRRNDNRRRRRRRNRRRRRRRNRNRNRRNRRR5
NDRRRNDRNDRRRRR
R1
RNDRNRRRRNRRRRNRRNDNDNDRRRRNDNRRR10
RRRNDRRNDNDNDNDNRRRRRRRNRRNDRNDRRRNDNDNDNDNRRR5
NDRNDRNDRNDRRRRR
* Please refer to foot notes on page 14.
w w w . e u r o s t e e l . c o . z a
Stainless Steel • Alluminium • Special Alloys
Sheet Plate Coil Tread Plate Bar Sections Extrusions Pipe Fittings FlangesPage 14
Media
Utility Ferritics
Corrosion(cont.)
Cr - Ni Austenitics Cr - Ni - Mo Austenitics Duplex
20ºC 60ºC 100ºC 20ºC 60ºC 100ºC 20ºC 60ºC 100ºC 20ºC 60ºC 100ºC
NaphthaleneNitrates of Na, K, NH3, AgNitric Acid (‹ 25%)Nitric Acid ( 50%)Nitric Acid ( 90%)Nitric Acid, fumingOil, Diesel, Petroleum SpiritsOils, essentialOils, lube with aromatic addsOils, vegetable & animalOxalic AcidPerchloric AcidPhenolPhosphoric Acid ( 20%)Phosphoric Acid ( 50%)Phosphoric Acid ( 95%)Phosphorous PentoxidePyridineSea WaterSilicic AcidSodium PeroxideSodium SilicateSodium SulphateStarchSugar, Syrup & JamSulphamic AcidSulphates (Na, K, Mg, Ca, Al, Fe)SulphatesSulphur Dioxide, drySulphur Dioxide, wetSulphur Dioxide, ag, soln (96%)Sulphur TrioxideSulphuric Acid (‹ 50%)Sulphuric Acid ( 70%)Sulphuric Acid ( 95%)Sulphuric Acid, fumingTannic Acid (10%)Tartaric AcidTrichloroethyleneUrea (30%)Water, pureYeast
RRRRRNDRRRRNRNRRNRNRNRNDRNRRNRRR6
RR12
NRRNRRNRNRNRNRNRR15
R2
RNRR5
RRR
RRR15
R15
NRNDRRRRNRNRRNRNRNRNDRNRRNRRR6
RR12
NRRNRRNRNRNRNRNR NR R2
RNRR5
RRR
RRNRNRNRNDRRRRNRNRRNRNRNRNDRNRRNRRNRRR12
NRRNRRNRNRNRNRNRNRNRNRNRR5
RRR
RRRRRRRRRRR6
NRRRRRRRR17
RR16
RRRR12
R18
RRRRRNRNRNRRRRRR5
RRR
RRRRNRR2
RRRRNR NRRRRRRRNRRNRRRRRNRRRRNRNRNRNRNRNRR2
RRR5
RRR
1 = Not if chlorides are present2 = Limited data3 = Depends on the acid4 = Dry acid fumes, attack may occur if moisture builds up5 = Anhydrous6 = Depends on concentration7 = May discolour with time8 = In strong solutions only when inhibited9 = Pitting possible in stagnant conditions10 = Possibility of pitting11 = May cause stress corrosion cracking12 = When free of SO2
13 = May cause contamination of product14 = Dilute hypochlorites can be used to sterilise some stainless steels15 = General corrosion may become excessive16 = 10%17 = In the absence of impurities18 = Dilute19 = Some attack at high temperatures
PITTING & CREVICE CORROSION RESISTANCE:
• NR = The material is not recommended • ND = No data is available • R = Indicates that the material is resistant to the named chemical up to the temperature shown, subject to limitations indicated by the footnotes.
Exposure in chloride containing media can result in localised corrosion.In order of increasing resistance to localised corrosion: 3CR12 < 430 < 304L < 316L < 2205
CONDITIONS FOR AVOIDING PITTING & CREVICE CORROSION:
• Design vessels for complete drainage - avoid sharp corners and stagnant areas.• Close crevices and lap joints by continuous welding.• Remove solids in suspension. Prevent sedimentation. Ensure continuous agitation and adequate flow rates.• Use compressive non-absorbent gaskets or inert sealing compounds.• Ensure non-impairment of passive surface. Repair / restore any affected areas
RRRRNRNRRRRRNRNRRRNRNRR5
RNRRNRRNRRRNRRRRNRNRNRNRNRNRNRRRR5
RRR
RRRRRRRRRRR6
NRRRRRRRR9
RR6
RRRRRRRRRRR5
R16
NRRRRRR5
RRR
RRRRNRNRRRRRN16
NRRRRRRRNRRR16
RRRRRRRRRRR5
NRNRNRNRRRR5
RRR
RRRRNRNRRRRRN16
NRRRRNRR5
RNRRR16
RNRRRR19
RRRNRRR5
NRNRNRNRRRR5
RRR
RRRRRRRRRRNRNRRRRR17
RRRRRRRRRRRRRRRR5
RNRRRRRR5
RRR
RRRRNRNRRRRRRNRRRRR17
RRRRRRRRRRRRRRRR5
RNRNRRRRR5
RRR
RRRRNDNDNDRRRRNRRRRR17
RRRRRRNRRRNRRRRNRRR5
NRNRNRNRRRR5
RRR
* Corrosion information courtesy of Columbus Stainless Steel (PTY) LTD. Values are typical guidelines and should not be used for design purposes.