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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.