alcan aerospace, transportation and industry

ALUMINIUMAND THE SEA

� ALCAN MARINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1. Alcan Marine: an entity dedicated to the maritime market . . . . . . . . . . . . . . . . . . 5

2. Presentation of the brochure "Aluminium and the Sea" . . . . . . . . . . . . . . . . . . . . . 5

� 1. ALUMINIUM, THE MARINE METAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1. Historical review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2. The development of aluminium-magnesium alloys of the 5000 family . . . . . . . . . . 14

3. Marine applications of aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4. Innovation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

� 2. ALUMINIUM’S ADVANTAGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1. A lightweight material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2. Diversity of semi-finished products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

3. Ease of processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4. Resistance to corrosion in marine environments . . . . . . . . . . . . . . . . . . . . . . . . 30

5. Impact on the environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

6. Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

7. Innovation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

� 3. ALUMINIUM ALLOYS IN MARINE APPLICATIONS . . . . . . . . . . . . . . . . . . . . . 33

1. The series of wrought alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

2. Designation of wrought aluminium alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3. Strain hardening alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4. Age hardening alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5. The principal alloys for marine applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

6. A new alloy, "Sealium®" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

7. The series of casting alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

8. Properties of casting alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

� 4. DESIGN, CALCULATION OF STRUCTURES AND FATIGUE BEHAVIOUR . . 53

1. Properties of aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

2. Determining the maximum static stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

3. Transposing from steel to aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .574. Fatigue behaviour of aluminium alloy structures . . . . . . . . . . . . . . . . . . . . . . . . 59

5. Service conditions of high speed ships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

6. General comments on the fatigue of metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

7. Specifics of the fatigue behaviour of aluminium . . . . . . . . . . . . . . . . . . . . . . . . 61

8. Classification of aluminium alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

9. Fatigue life of weldments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

10. Influence of design and fabrication arrangements . . . . . . . . . . . . . . . . . . . . . . . 68

11. Reference standards and regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

� 5. FORMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

1. Receiving and storage of semis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

2. Cutting to shape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

3. Forming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

� 6. WELDING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

1. Historical review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

2. Specifics of welding aluminium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

3. Implications for the design and execution of welds . . . . . . . . . . . . . . . . . . . . . . 89

4. Arc welding processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

5. Storage of semi-finished products and filler wire . . . . . . . . . . . . . . . . . . . . . . . . 97

6. Surface preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

7. Joint preparation and setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982

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8. Filler metal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

9. Finishing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

10. Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

11. Weld imperfections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

12. Repairs and fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

13. Laser welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

14. Friction Stir Welding (FSW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

15. Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

� 7. ALUMINIUM BONDING AND SPECIAL ASSEMBLIES . . . . . . . . . . . . . . . . . 115

1. Screw and bolt fastenings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

2. Machine rivets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

3. Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

4. Transition joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

� 8. ELECTRICAL SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

1. General rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

2. Direct current installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

3. Alternating current installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

� 9. FIRE RESISTANCE OF ALUMINIUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

1. The Falklands conflict . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

2. Reaction to fire of aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

3. Classification of aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

4. Passive protection of aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

5. Thermal properties of aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

6. Change in the physical properties of aluminium as a function

of temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

� 10. CORROSION BEHAVIOUR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

1. Characteristics of marine environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

2. Corrosion behaviour of aluminium under control of the natural film of oxide . 148

3. Influence of the pH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

4. Influence of alloying elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

5. Forms of aluminium corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

6. Bimetallic corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

7. Aluminium tarnishing and blackening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

8. Role and prevention of marine fouling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

9. Effects of welding and design arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . 159

10. Sensitivity to corrosion of aluminium alloys

in marine applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

11. Corrosion tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

� 11. PROTECTION OF ALUMINIUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

1. Anodising . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

2. Painting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

3. Cathodic protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

� 12. APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

1. Standards of mechanical properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

2. Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

3. English/ French/German/Spanish glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

4. Key and photo credits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

5. Useful addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

A L C A N

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THE GROWTH IN THE USE of alu-minium in shipbuilding, espe-

cially in the construction of high-speed ships, prompted the PechineyGroup in 2001 to create PECHINEYMARINE, an entity endowed withsignificant resources and capableof handling all aspects of the "mar-itime markets" in aluminium.

Pechiney’s first brochure entitled"Aluminium and the Sea" was pub-lished in 1992 and received anexcellent world-wide response in

maritime circles, including navalarchitects, shipyards and shipown-ers. The brochure answered theneeds of users wishing to use alu-minium in marine applications andwanting to know more about it.

Given the scale of the growth inaluminium usage in larger vessels -100 metres and more in length -this second brochure explores cer-tain major aspects of shipbuildingin aluminium such as arc weldingand fatigue strength in more depth.

Experience acquired in shipbuild-ing over many decades, especiallywith high-speed ships, illustratesthe benefits which aluminium canoffer to naval architects, yards andshipowners and more generally tousers of aluminium for marineapplications.

After the Pechiney integration intothe Alcan Group in 2004, ALCANMARINE succeds PECHINEYMARINE.

THE PRINCESS

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1.ALCAN MARINE: ANENTITY DEDICATEDTO THE MARITIMEMARKET

The evolution that we have seen inthe maritime uses of aluminium inhigh-speed ships, in shipbuilding(yachts, service vessels, super-structures) and in offshore applica-tions calls for a fuller considerationand investigation of the technicalaspects of the use of aluminium inmarkets that have a high engineer-ing content.

In order to better respond to theneeds and concerns of users ofaluminium semi-finished products,Alcan Marine brings together engi-neering skills that are foundthroughout the Alcan Group:

� in production, with our produc-tion plants making aluminiumsheets, plates and shapes, � in research and development,with specialists in the calculationof structures and fatigue and met-allurgists developing new alloys aswell as optimising the propertiesof existing alloys,� in the global commercial net-work of the Alcan Group.

Alcan Marine has three mainobjectives:� to develop the marine applica-tions of aluminium,� to promote innovation in alu-minium shipbuilding,� to offer its clients the benefit ofAlcan Group’s many years of expe-rience and expertise in the marineapplications of aluminium.

2.PRESENTATION OF THE BROCHUREALUMINIUM ANDTHE SEA

This brochure is published as partof our desire to provide alu-minium users with a sound infor-mation base on the applicationsof aluminium.

It addresses all the players in theindustry - naval architects, design-ers and research consultancies,shipyards, ship owners and opera-tors - who use aluminium inmarine applications: ships, off-shore equipment and coastalinstallations.

THE LYNX

A number of important aspectshave been developed, amongthem arc welding, now the mostwidespread method of fabricationin shipbuilding, and fatiguestrength. The increase in the sizeof aluminium vessels is a recentphenomenon and brings with it itsown particular problems.

It goes without saying that thesole aim of this brochure is toinform the reader about the pro-perties of aluminium alloysintended for marine uses andabout methods of application.

It cannot be a substitute for spe-cialist literature that deals with thetechnologies used in aluminiumshipbuilding. Nor can it take prece-dence over the regulations of clas-sification societies, standards andcodes of engineering practice withwhich designers are bound tocomply, including the selection ofaluminium alloys.

This brochure is the work ofChristian VARGEL, a former ChiefEngineer in the Pechiney Groupand author of the book Corrosionde l'Aluminium, 528 pages, pub-lished by DUNOD in February1999 and published in English byELSEVIER in October 2004 underthe title Corrosion of Aluminium,

with the assistance of:

Myriam Bouet GriffonNathalie FerrerEvelyne HankChristine HénonJacques ChanteclairAlexandre DuranJean-Christophe ErhströmHenri GérardChristian HantraisJean-François HardouinBenoît LancrenonJérôme LucaesFranck Planquaisof the Alcan group (ATI,Engineered Product BusinessGroup),

Henri MignotPhilippe Ricouof Bureau Veritas,

Marc Puechof Avdel Textron,

Antoine Nobiliof DMC Nobelclad,

Jean-Marie Garnierof Unifrax France,

Jean-Claude Szwarcof Air Liquide Welding.

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Notes:

For the sake of simplicity,the term "ALUMINIUM" asused in this brochure meansaluminium alloys and notthe unalloyed metal.

All the figures given in thisbrochure are in the units ofthe International System (IS).

This publication is not a contract document and shall in no way incur the liability of Alcan on account of theinformation contained herein.

This information is given purely as a guide and it is for the reader to verify its accuracy and to consult the AlcanGroup and other experts before use.

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THE GLOBAL CHALLENGE

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THE VESUVIO JET