Encyclopedia Of Corrosion Technology

Encyclopedia of

CORROSION TECHNOLOGY

Copyright © 2004 by Marcel Dekker, Inc.

CORROSION TECHNOLOGY Editor Philip A. Schweitzer, P.E. Consultant York, Pennsylvania 1. Corrosion Protection Handbook: Second Edition, Revised and Expanded, edited by Philip A. Schweitzer 2. Corrosion Resistant Coatings Technology, Ichiro Suzuki 3. Corrosion Resistance of Elastomers, Philip A. Schweitzer 4. Corrosion Resistance Tables: Metals, Nonmetals, Coatings, Mortars, Plastics, Elastomers and Linings, and Fabrics: Third Edition, Revised and Expanded (Parts A and B), Philip A. Schweitzer 5. Corrosion-Resistant Piping Systems, Philip A. Schweitzer 6. Corrosion Resistance of Zinc and Zinc Alloys: Fundamentals and Applications, Frank Porter 7. Corrosion of Ceramics, Ronald A. McCauley 8. Corrosion Mechanisms in Theory and Practice, edited by P. Marcus and J. Oudar 9. Corrosion Resistance of Stainless Steels, C. P. Dillon 10. Corrosion Resistance Tables: Metals, Nonmetals, Coatings, Mortars, Plastics, Elastomers and Linings, and Fabrics: Fourth Edition, Revised and Expanded (Parts A, B, and C), Philip A. Schweitzer 11. Corrosion Engineering Handbook, edited by Philip A. Schweitzer 12. Atmospheric Degradation and Corrosion Control, Philip A. Schweitzer 13. Mechanical and Corrosion-Resistant Properties of Plastics and Elastomers, Philip A. Schweitzer 14. Environmental Degradation of Metals, U. K. Chatterjee, S. K. Bose, and S. K. Roy 15. Environmental Effects on Engineered Materials, edited by Russell H. Jones 16. Corrosion-Resistant Linings and Coatings, Philip A. Schweitzer 17. Corrosion Mechanisms in Theory and Practice: Second Edition, Revised and Expanded, edited by Philippe Marcus 18. Electrochemical Techniques in Corrosion Science and Engineering, Robert G. Kelly, John R. Scully, David W. Shoesmith, and Rudolph G. Buchheit 19. Metallic Materials: Physical, Mechanical, and Corrosion Properties, Philip A. Schweitzer 20. Encyclopedia of Corrosion Technology: Second Edition, Revised and Expanded, Philip A. Schweitzer 2 1 . Corrosion Resistance Tables: Metals, Nonmetals, Coatings, Mortars, Plastics, Elastomers and Linings, and Fabrics: Fifth Edition, Revised and Expanded (Parts A, B, C, and D), Philip A. Schweitzer

ADDITIONAL VOLUMES IN PREPARATION

Copyright © 2004 by Marcel Dekker, Inc.

Encyclopedia of

CORROSION TECHNOLOGY Second Edition, Revised and Expanded

Philip A. Schweitzer, RE. Consultant York, Pennsylvania, U.S.A.

MARCEL

MARCEL DEKKER, INC. i

DEKKER

Copyright © 2004 by Marcel Dekker, Inc.

N E W YORK • BASEL

Although great care has been taken to provide accurate and current information, neither the author(s) nor the publisher, nor anyone else associated with this publication, shall be liable for any loss, damage, or liability directly or indirectly caused or alleged to be caused by this book. The material contained herein is not intended to provide specific advice or recommendations for any specific situation. Trademark notice: Product or corporate names may be trademarks or registered trademarks and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress. ISBN: 0-8247-4878-6 This book is printed on acid-free paper. Headquarters Marcel Dekker, Inc. 270 Madison Avenue, New York, NY 10016, U.S.A. tel: 212-696-9000; fax: 212-685-4540 Distribution and Customer Service Marcel Dekker, Inc. Cimarron Road, Monticello, New York 12701, U.S.A. tel: 800-228-1160; fax: 845-796-1772 Eastern Hemisphere Distribution Marcel Dekker AG Hutgasse 4, Postfach 812, CH-4001 Basel, Switzerland tel: 41-61-260-6300; fax: 41-61-260-6333 World Wide Web http://www.dekker.com The publisher offers discounts on this book when ordered in bulk quantities. For more information, write to Special Sales/Professional Marketing at the headquarters address above. Copyright © 2004 by Marcel Dekker, Inc. All Rights Reserved. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher. Current printing (last digit): 10 9 8 7 6 5 4 3 2 1 PRINTED IN THE UNITED STATES OF AMERICA

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Preface Corrosion is expensive and can be hazardous. It is costly to replace and/or repair equipment, structures, and other miscellaneous items that have been damaged as a result of corrosion. It can be hazardous when corrosion has weakened a portion of a vessel, bridge, or other structure causing it to fail, resulting in injury to persons and/or fires or explosions. Materials are capable of corroding as the result of prolonged exposure to the atmosphere as well as contact with aggressive media. It is the purpose of this encyclopedia to explain the many terms associated with corrosion, including the various types and forms of corrosion, and metallurgical and other terms as they relate to the corrosion process. All the most commonly used materials of construction have been included because the various forms and types of corrosion affect different materials in different ways. Methods whereby corrosion can be controlled or prevented are explained. Information regarding areas of application, conditions of protection, and conditions under which they are useful have been included. Ample references are supplied to permit more detailed study of many of the topics. This encyclopedia will provide insight into the causes and problems of corrosion and offer some assistance in solving these problems. Philip A. Schweitzer, P.E.

LLL

Copyright © 2004 by Marcel Dekker, Inc.

Contents Preface Abrasion Corrosion Absorption Acid Acid Brick Acid Mine Waters Acid Rain Acrylate-Butadiene Rubber (ABR) and Acrylic Ester–Acrylic Halide (ACM) Rubbers Acrylic Ester–Acrylic Halide Rubbers Acrylonitrile-Butadiene-Styrene (ABS) Adsorption Aliphatic Hydrocarbons Alkaline Alligatoring Alloy Alloy B-2 Alloy C-276 Alloy C-22 (N06022) Alloys G (N06007), G-3 (N06985), and G-30 (N06030) Alloy 600 (N06600) Alloy 625 (N06625) Alloy 686 (N06686) Aluminum and Aluminum Alloys Aluminum Bronze Ambient Temperature Anaerobic Corrosion Annealing Anode Anodic Protection Anodic Undermining Anodizing

iii 1 1 1 3 3 3 4 4 5 5 7 7 7 8 8 15 17 18 22 25 26 28 39 39 41 42 43 43 43 43

Aramid Fibers Atmospheric Corrodents Atmospheric Corrosion Austenite Austenitic Ductile Cast Irons Austenitic Gray Cast Irons Austenitic Stainless Steels References

44 44 44 51 52 52 52 73

Bacterial Corrosion Barrier Coatings Base Baumé Scale Bearing Corrosion Biological Corrosion Bisphenol Polyesters Blister Cracking Blistering Boron Carbide Borosilicate Glass Brass Butadiene-Styrene Rubber (SBR, Buna-S, GR-S) Butyl Rubber (IIR) and Chlorobutyl Rubber (CIIR) References

75 75 75 75 76 76 79 80 82 84 84 84

Cadmium Coatings Capped Steel Carbide Precipitation Carbon Carbon Fibers Carbon Fiber Reinforced Thermoplastics Carbon/Graphite Yarns

93 93 93 94 97

84 87 91

97 98 Y

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YL

Carbon and Low-Alloy Steels Carburization Cast Aluminum Cast Copper Alloys Cast Irons Cast Nickel and Nickel Base Alloys Cast Stainless Steels Cathode Cathodic Corrosion Cathodic Delamination Cathodic Protection Caustic Embrittlement Cavitation Corrosion Cell Potentials Ceramic Materials C-Glass Checking Chemical Synonyms Chlorinated Polyvinyl Chloride (CPVC) Chlorobutyl Rubber Chlorosulfonated Polyethylene Rubber (Hypalon) Chromating Chromium Coatings Clad Steels Coatings Cobalt Alloys Cold Water Pitting Columbium Composite Laminates Composites Concentration Cells Conversion Coatings Copolymer Copper and Copper Alloys Corrosion Allowance Corrosion Coupons Corrosion Fatigue Corrosion Inhibitors Corrosion Measurement Corrosion Mechanisms Corrosion Monitoring Corrosion Testing Corrosion Testing for Environmentally Assisted Cracking (EAC) Corrosion Under Insulation

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98 101 102 103 105 108 110 119 119 119 119 127 127 128 128 131 132 132 135 135 135 143 143 143 145 160 160 160 161 161 162 162 162 162 174 174 174 175 180 180 185 185 190 191

Crack-Inducing Agents Crevice Corrosion Critical Crevice Corrosion Temperature Critical Pitting Temperature Cycoloy References

193 196

Dealloying Decarburization Deposit Attack Deposit Corrosion Dew Point Corrosion Dezincification (Dealloying) Differential Aeration Cell Dissimilar Metal Corrosion Ductile (Nodular) Iron Duplex Stainless Steels Duralumin Duriron References

201 201 201 201 201 201 202 202 203 203 209 209 209

E-Glass Elastomer Cross Reference Elastomers Electrochemical Corrosion Electrolysis Electrolyte Embedded Iron Corrosion Embrittlement Enameling Engineering Plastic Epoxy Resins Erosion Corrosion Esters Ethylene-Acrylic (EA) Rubber Ethylene-Chlorotrifluoroethylene (ECTFE) Ethylene-Chlorotrifluoroethylene (ECTFE) Elastomer Ethylene-Propylene Rubbers (EPDM and EPT) Ethylene-Tetrafluoroethylene (ETFE) Ethylene-Tetrafluoroethylene (ETFE) Elastomer Exfoliation Corrosion References

211 211 212 226 228 228 228 228 229 229 229 232 233 233

196 197 197 198

234 238 240 246 249 250 250

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YLL

Ferrite Ferritic Stainless Steels Fiberglass Fiber-Reinforced Plastics (Composites) Filiform Corrosion Fluorel Fluoroelastomers (FKM) Fluorinated Ethylene Propylene (FEP) Fluorocarbon Resins Fluoropolymer Resins Fluorosilicone Rubber Forms of Corrosion Fretting Corrosion Fuel Ash Corrosion Furan Resins References

265 266 269 270 270 271 271 272 274

Galvanic Corrosion Galvanic Protection Galvanized Iron Galvanized Steel Gaseous Phase Corrosion General Corrosion Glass Coatings Glass Fiber Reinforcement Glass Linings Glassed Steel Graphite Fibers Graphitization (Graphitic Corrosion) Green Plague Green Rot Green Rust Grooving Corrosion Grout References

277 278 278 279 281 281 281 281 281 283 283 285 285 285 285 286 286 286

Halar Halogenated Polyester Resins Hastelloy Hastelloy Alloy C-2000 Heat-Affected Zone (HAZ) High-Silicon Iron High-Temperature Corrosion Hydrogen Damage Hydrogen Probes Hydrolysis

287 287 287 287 289 290 290 295 301 301

Copyright © 2004 by Marcel Dekker, Inc.

251 251 257 258 258 258 258

Hylar Hypalon References

301 301 301

Immersion Coatings Impervious Graphite Impingement Corrosion Attack Inhibitors Inorganic Coatings Intergranular Corrosion ISO Isocorrosion Diagram Isophthalic Esters Isoprene Rubber (IR) References

303 303 303 303 303 307 308 308 309 309 311

Kalrez Kevlar Killed Carbon Steel Knife-Line Attack Kynar

313 313 313 315 316

Lamellar Corrosion Layer Corrosion Lead and Lead Alloys Linings, Sheet Liquid Applied Linings Liquid Metal Embrittlement Local Corrosion Cell Localized Corrosion Low-Alloy Steels References

317 317 317 319 319 325 329 330 330 330

Magnesium Alloys Malleable Iron Marine Coatings Marine Environment Martensite Martensitic Stainless Steels Measuring Corrosion Membrane Mercury Corrosion Metal Dusting Metallic Coatings Microalloyed Steels Microbial Corrosion Mils Per Year (MPY)

333 333 334 334 334 335 347 347 348 348 348 349 350 353

YLLL

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Monel Monitoring Corrosion Monolithic Surfacings Monomer Mortars References

354 359 361 361 361 384

Natural Rubber (NR) Neoprene (CR) Neutral Solution Nexus Nickel Nickel Coatings Niobium Nitriding Nitrile Rubber (NBR, BUNA-N) Noble Metal Normalizing NOx Nylon References

387 396 402 402 403 407 410 415 415 419 419 419 420 420

Oil Ash Corrosion Oil/Gas Well Corrosion Inhibitors Oxidation Oxidizing Acids Oxidizing Agent Oxygen Concentration Cell Ozhennite Alloys Ozone References

421 421 421 421 425 425 425 425 425

Paint Parting Passivation Passive Films Passive Metal Patenting Patina Pearlite Perfluoroalkoxy (PFA) Perfluoroelastomers (FPM) Permeation pH Phenol-Formaldehyde Resin Phenolic Resins Phosphating

427 427 427 427 428 429 429 429 429 433 436 438 439 441 444

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Pitting Pitting Potential Pitting Resistance Equivalent Number Plastics Polarization Polyamides (PA) Polyamide/Acrylonitrile-ButadieneStyrene Alloy Polyamide Elastomers Polyamide-Imide (PAI) Polybutadiene Rubber (BR) Polybutylene (PB) Polybutylene Terephthalate (PBT) Polycarbonate (PC) Polycarbonate/AcrylonitrileButadiene-Styrene Alloy Polycarbonate/PolybutyleneTerephthalate Alloy Polychloroprene Polyester (PE) Elastomer Polyester Fibers Polyetheretherketone (PEEK) Polyethersulfone (PES) Polyethylene (PE) Polymers Polymer Concretes Polyphenylene Oxide (PPO) Polyphenylene Sulfide (PPS) Polypropylene (PP) Polysiloxane Rubber Polysulfide Rubbers (ST and FA) Polysulfone (PSF) Polytetrafluoroethylene (PTFE) Polyurethane (PUR) Polyvinyl Chloride (PVC) Polyvinylidene Chloride (Saran) Polyvinylidene Fluoride (PVDF) Potential–pH Diagrams (Pourbaix Diagrams) Poultice Corrosion Precipitation-Hardening Stainless Steels Pyrex Pyrolysis References

444 445 445 445 445 446 449 449 451 452 455 457 459 460 460 460 460 463 463 465 466 470 482 483 485 488 491 491 496 500 503 506 509 511 514 515 516 527 528 528

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L[

Quench Quench Annealing Quenching and Tempering (Hardening and Tempering)

529 529

Radiation Corrosion Rebar Corrosion Red Brass Reducing Acids Reducing Atmosphere Corrosion Riddick’s Corrosion Index Rimmed Steel Rust References

531 531 531 532 538 538 538 538 538

Sacrificial Anode Saran Scab Corrosion Season Cracking Selective Corrosion Selective Leaching Semikilled Steel Sensitization S-Glass Sheet Linings Sheltered Corrosion Shot Peening Silicon Carbide Silicon Carbide Fibers Silicone Silicone and Fluorosilicone Rubbers Siloxirane Soil Corrosion SOLEF Solution Quenching Spheradizing Stainless Steels Stress Corrosion Cracking (SCC) Stress Relief Superaustenitic Stainless Steels Styrene-Butadiene-Styrene (SBS) Rubber Styrene-Ethylene-Butylene-Styrene (SEBS) Rubber Sulfate-Reducing Bacteria Sulfidation

539 539 539 539 540 540 540 540 540 540 554 554 556 556 556

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529

559 564 565 568 568 568 568 569 571 572 583 584 586 586

Sulfidic Corrosion Sulfide Stress Cracking Super Pro 230 Superferritic Stainless Steels References

586 586 586 586 590

Tantalum Tantalum-Based Alloys Tarnish Technoflon Teflon Tefzel Tempering Terephthalic Polyesters Thermoplastic Alloys Thermoplastic Composites Thermoplastic Elastomers (TPE), Olefinic Type Thermoplastic Polymers Thermoplasts Thermoset Composites Thermoset Laminates Thermoset Polymers Thermoset Reinforcing Materials Tin Coatings (Tin Plate) Titanium Titanium Alloys Transgranular Corrosion Triax References

591 594 600 600 601 601 601 601 603 603 603 604 604 606 607 607 609 611 613 614 622 623 623

Ultrasonic Measurement Ultraviolet Light Degradation Ultraviolet Stabilizer Underfilm Corrosion Unified Numbering System Uniform Corrosion Urethane (AU) Rubbers References

625 625 626 626 626 628 632 633

Vapor Vapor Barrier Vapor Corrosion Vapor Phase Corrosion Inhibitors Verdigris Vinyl Ester Resins

635 635 635 635 635 635

[

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Vinylidene Fluoride Elastomers (HFP, PVDF) Viton Vitreous Enamel Vitreous Enamel Coatings Vitrified Clay Pipe References

638 640 641 641 641 642

Waterline Attack Weathering Weathering Steels Weld Rusting Wet Storage Stain White Iron White Rust Wood Worm Track Corrosion

643 643 643 644 644 645 645 645 646

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Wrought Iron References

646 646

Xenoy

647

Yellow Brass References

647 647

Zinc and Zinc Alloys Zincating Zinc Embrittlement Zircaloys Zirconium and Zirconium Alloys Zymaxx References

649 660 660 660 660 670 671

A ABRASION CORROSION See “Erosion Corrosion.” ABSORPTION See also “Sheet Linings.” Unlike metals, polymers will absorb varying quantities of the corrodents they come into contact with, especially organic liquids. This can result in swelling, cracking, and penetration to the substrate. Swelling can cause softening of the polymer. If the polymer has a high absorption rate, permeation will probably occur. An approximation of the expected permeation and/or absorption of a polymer can be based on the absorption of water. Some typical rates are shown in Table A.1. Table A.2 shows the absorption of selected liquids by FEP, and Table A.3 shows the absorption of selected liquids by PFA. ACID Any chemical compound containing hydrogen capable of being replaced by positive elements or radicals to form salts. In terms of the dissociation theory, it is a compound which on dissociation in solution yields excess hydrogen ions.

Table A.1 Polymer

Water Absorption Rates of Polymers Water absorption 24 h at 73°F (23°C) (%)

PVC CPVC PP (Homo) PP (Co) PE (EHMW) E-CTFE PVDF Saran PFA ETFE PTFE FEP

0.05 0.03 0.02 0.03
0.01
0.1
0.04 nil
0.03 0.029
0.01
0.01 

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Table A.2

Absorption of Selected Liquidsa by FEP

Chemical

Temperature (°F/°C)

Range of weight gains (%)

365/185 394/201 354/179 400/204 172/78 172/78 372/190 410/210 250/121 154/68 230/110 392/200b

0.3–0.4 0.6–0.8 0.4–0.5 0.3–0.4 0.3–0.4 2.3–2.4 0.1–0.2 0.7–0.9 2.0–2.3 1.7–2.7 0.7–0.8 1.8–2.0

Aniline Acetophenone Benzaldehyde Benzyl alcohol n-Butylamine Carbon tetrachloride Dimethyl sulfoxide Nitrobenzene Perchlorethylene Sulfuryl chloride Toluene Tributyl phosphate

a168-hour exposure at their boiling points. bNot boiling.

Table A.3

Absorption of Representative Liquids by PFA

Liquida Aniline Acetophenone Benzaldehyde Benzyl alcohol n-Butylamine Carbon tetrachloride Dimethyl sulfoxide Freon 113 Isooctane Nitrobenzene Perchlorethylene Sulfuryl chloride Toluene Tributyl phosphate Bromine, anhydrous Chlorine, anhydrous Chlorosulfonic acid Chromic acid 50% Ferric chloride Hydrochloric acid 37% Phosphoric acid, concentrated Zinc chloride

Temperature (°F/°C) 365/185 394/201 354/179 400/204 172/78 172/78 372/190 117/47 210/99 410/210 250/121 154/68 230/110 392/200b –5/–22 248/120 302/150 248/120 212/100 248/120 212/100 212/100

Range of weight gains (%) 0.3–0.4 0.6–0.8 0.4–0.5 0.3–0.4 0.3–0.4 2.3–2.4 0.1–0.2 1.2 0.7–0.8 0.7–0.9 2.0–2.3 1.7–2.7 0.7–0.8 1.8–2.0 0.5 0.5–0.6 0.7–0.8 0.00–0.01 0.00–0.01 0.00–0.03 0.00–0.01 0.00–0.03

aLiquids were exposed for 168 hours at the boiling point of the solvents. The acidic reagents were

exposed for 168 hours.

bNot boiling.

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ACID BRICK Acid brick is brick made from selected clays having a higher silica content than ordinary firebrick and containing little acid-soluble components. It is used to line vessels to impart corrosion resistance against hot acid or erosion–corrosion attack. It is fired at higher temperatures and for longer periods of time than the same clay when used to make “common” brick. Acidresistant brick is covered by ASTM Specification C-279. The two most commonly used bricks are red shale and fireclay. These are used for all applications except those where the exposure is to strong alkali or hydrofluoric acid. Of the two, the most frequently used is red shale. Red Shale Brick Red shale brick is usually described as meeting type L in ASTM C-279. These bricks provide a lower absorption rate than fireclay and are usually somewhat more brittle. They are applied in those areas where lowest absorption masonry is desired. Fireclay Fireclay brick is usually described as meeting type H in ASTM C-279. It contains a higher proportion of alumina and lower percentages of silica and iron than does shale brick. Fireclay bricks have a higher absorption rate than shale bricks, although some manufacturers provide a denser brick that will meet type L for absorption. These bricks are usually selected for outdoor exposures where rapid thermal changes occur, since they are less brittle than the shale brick. Since they also have a low iron content, they are used in process equipment where this characteristic is important in maintaining product purity. Carbon Brick Carbon brick is used in areas exposed to strong alkali (pH 12.5+) and hydrofluoric acid, or fluoride salts in an acid medium. These bricks are more shock resistant than either red shale or fireclay brick, permitting them to be used in areas where rapid pressure changes take place, a condition that can cause shale or fireclay to spall. Silica Brick All silica brick is used in very high acid concentrations, particularly in phosphoric acid. See Ref. 1. ACID MINE WATERS These are waters that are present in some underground coal mines. They are extremely corrosive because of their free acidity and the presence of high concentrations of ferric and sulfate ions. Their corrosiveness is a result of the aerial and microbial oxidation of pyrite sulfur present in the coal seams or related strata. ACID RAIN When rain has a pH less than 5.6 it is classified as acid rain. It is the result of atmospheric moisture coming into contact with sulfur dioxide gases from industrial emissions and/ or with nitrogen oxide gases from car exhausts. See “Atmospheric Corrosion.”

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