AL-KHODARI AL-KHODARI INDUSTRIAL TRADING & INDUSTRIAL TRADING &

SERVICESSERVICES

Dealing with corrosionDealing with corrosion

Company headlines

Know-how in processes and installations for powders and liquids, Consulting and implementing installations with optimal R.O.I.,  Reliable process solutions with minimal complexity, Innovative and active supporting in process issues.

Services

Process engineeringEngineering• Mechanical• Electrical

ProductionProcess controlMechanical installationElectrical installationMaintenance & service

Experience & know-how

Milk of lime• Storage & dosing of (quick) lime• Mixing, storage & dosing of milk of lime

Slurry handling• Coal, sand, sulfur, magnesium oxide, etc.

Paint & compoundingStorage, dosing and handling of hard-to-handle materialsGlue preparation• Preparing, cooking & dosing of PVA or starch

based glueLiquid handling• Dosing skids

Storage & handling corrosive materials

References

Akzo NobelAkzo Salt Chemistry Carmeuse ChemetallDegussaInterbrew Nederland Koninklijke Marine – Royal Dutch NavyNestlé Nederland PPG - SigmaKalon Coatings Rockwool Lapinus B.V. Sabic MelafSHELL Ned. ChemieSmurfit Kappa PackagingFokker Nederland – Parts for JSF and Apache 9 helicopterWaterschap Zuiveringschap Limburg – waste water treatmentWaterschap Zuiveringschap Brabant – waste water treatment

Designing & engineering on material behavior

CorrosionErosionViscosityChemistryHazard

Corrosion

General CorrosionPitting CorrosionCrevice CorrosionStress Corrosion CrackingGalvanic CorrosionMicrobiologically Influenced CorrosionSulphide Stress Corrosion CrackingIntergranular Corrosion

Pitting corrosionDefect in passive layer allows metal to dissolve

Passive oxide layer

Concentrated iron chloride solutionCathodi

c

Anodic

Corrosion products

Electrochemical processElectrochemical process

Pitting corrosion

Inhibitors:Inhibitors:Chloride (catalyst)High temperaturesAcidic conditions, low pH, such as CO2, H2S

Damaged oxide layer (chemically inhibited)

Pitting corrosion

Crevice corrosion

Similar to pitting corrosion

Occurring:Occurring:Under gaskets, Sharp re-entrant corners Incomplete weld penetration Overlapping surfaces

Pipe weldings

Welding pre-

treatment

Sufficient weld

penetration

Sufficient weld

penetration

Insufficient weld

penetration

Sufficient weld

penetration

crevice

crevice

crevice

Crevice corrosion

Pitting & crevice resistance

High grades of chromium, molybdenum and nitrogenPitting Resistance Equivalent number (PRE):

PRE = %Cr + 3.3 x %Mo + 16 x %NPRE = %Cr + 3.3 x %Mo + 16 x %N

Pitting & Crevice resistance

316L

316L

Chloride content water

Chloride content water

Temperature 88-100 °F 31-38 °C

75% recoveryFlow rate

[GPM]Chloride [ppm]

Feed Flow 1667 1400

Brine Flow 417 5595

Permeate Flow 1250 0,5

68% recoveryFlow rate

[GPM]Chloride [ppm]

Feed Flow 1838 1400

Brine Flow 588 4375

Permeate Flow 1250 0,5

Chloride content water

316L

316L

FEED

68% 75%

Stress Corrosion Cracking

InhibitorsInhibitors::Stress and corrosive environmentStainless steelElevated temperature

Only applicable to austenitic Only applicable to austenitic steelsteel

(201, 301, 303, 304, 305, 316, 321, 347, 631)

Stress Corrosion Cracking

Galvanic corrosion

Contact of dissimilar metals in electrically conductive liquid Welds, containing ferrites and due to different structureContact metal with corrosion products

Contact corrosion accelerates pitting & crevice corrosion

Contact corrosionContact corrosion

Galvanic corrosion

Microbiologically Influenced Corrosion (MIC)

Microbiologically Influenced Corrosion (MIC)

InhibitorsInhibitors::Stagnant areas of flowMicro-organismsBio-films of (other) micro-organismsSurface roughnessNutrientsOxygen!

Microbiologically Influenced Corrosion (MIC)

Types of organismsTypes of organisms::Algae (Probable in saltwater with O2)

Fungi (Improbable)Bacteria (Aerobic & Anaerobic)

Microbiologically Influenced Corrosion (MIC)

Tubercles formation facilitating

pitting/crevice corrosion

Corrosion underneath biofilm

Bio-film creating isolated

environment

Microbiologically Influenced Corrosion (MIC)

Prevention / resistancePrevention / resistance::Maintaining cleanlinessMonitoring quality of waterSmooth surfacesAvoiding stagnant areas

Stainless steels with Stainless steels with molybdenum > 6% are molybdenum > 6% are

virtually resistant to MICvirtually resistant to MIC

PRE = %Cr + 3.3 x %Mo + 16 x PRE = %Cr + 3.3 x %Mo + 16 x %N%N

Sequence of corrosion

1. Crevice corrosion at gaskets, crevice / galvanic corrosion at welds.

2. Contact corrosion due to corrosion products.

3. Algae settle on corrosion induced roughness

4. Bacteria settling at algae/roughness5. Formation bio-films and degrading agents6. Acceleration of corrosion processes up to

1000 times of ‘normal’ process

Unusual and excessive degree Unusual and excessive degree of corrosion can occur of corrosion can occur

unpredictably, due to specific unpredictably, due to specific local conditions local conditions

Chloride content water

316L

316L

FEED

68% 75%

Pictures RO skid

Penetrated weld

Crevice corrosion

Contact/galvanic corrosion

Pictures RO skid

Pitting corrosion

Facilitated by stagnant water

Pictures RO skid

Contact corrosion

Corrosion by polluted welding material

Pictures RO skid

Contact corrosion by polluted welds

Pictures RO skid

Contact corrosionConsequential MIT on rough surface

Density MIT related to lines

Corrosion processes related to stagnant water

Conclusions

Basic types corrosion: pitting & crevice corrosionPrimary corrosion propagated by contact corrosion and Microbiological Influenced CorrosionStagnant areas over a longer period of time are facilitating & accelerating corrosion enormouslyStainless steel 316L in RO skid willwill corrodeWorst case circumstances were availableSerious riskSerious risk is unpredictability of corrosion reaction velocity; several cases of sudden unusual degree of corrosion are known

AL-KHODARI AL-KHODARI INDUSTRIAL TRADING & INDUSTRIAL TRADING &

SERVICESSERVICES

Specialized in process installations Specialized in process installations for handling dry and liquid materialsfor handling dry and liquid materials

Proposed actions

Survey of similar installations at Aramco:• Compare differences in materials / set-up• Examine water compositions• Compare biological analyses• Evaluate state of corrosion to age

Conclude either whether risk level incurred in common practice is acceptable or common practice is to be re-defined