Copper has good resistance to corrosion in marine environments and in seawater with moderate flow velocities. These properties are enhanced by alloying copper with nickel, iron, manganese, zinc (brass), lead, beryllium and other metals.
Copper alloys used in marine applications can be categorized into four groups:
- Copper-Nickels
- Bronzes
- Brasses
- Copper-Beryllium
Some alloys, such as leaded brasses, have excellent machinability, while others are made to enhance strength, wear resistance, anti-galling and cold formability. In general, however, copper containing alloys are relatively easier to machine than other metals and alloys.
Applications:
Typical applications for copper-containing alloys in marine environments include:
- heat exchangers and condensors
- seawater piping
- hydraulic tubing
- pump and valve components
- bearings
- fasteners
- marine fittings
- propellers
- shafts
- offshore sheathing
- aquaculture cages
Copper Alloys for Marine Environments (Content Wt. %)
| Alloy | EN No. or Trade Name | UNS No. | Cu | Ni | Fe | Mn | Zn | Al | Sn | Other |
| Cu-Ni | CW352H | C70600 | Bal. | 10 | 1.5 | 1 | - | - | - | - |
| Cu-Ni | CW353H | C71640 | Bal. | 30 | 2 | 2 | - | - | - | - |
| Cu-Ni | CW354H | C71500 | Bal. | 30 | 0.7 | 0.7 | - | - | - | - |
| Cu-Ni-Cr | Def Stan 02-824 | - | Bal. | 30 | 0.8 | 0.8 | - | - | - | Cr: 1.8 |
| Cu-Ni-Cr | - | C72200 | Bal. | 16 | 0.7 | 0.7 | - | - | - | Cr: 0.5 |
| Cu-Ni-Al | Nibron Special™ | - | Bal. | 14.5 | 1.5 | 0.3 | - | 3 | - | - |
| Cu-Ni-Al | Def Stan 02-835 | C72420 | Bal. | 15 | 1 | 5 | - | 1.5 | - | Cr: 0.4 |
| Cu-Ni-Sn | - | C72900 | Bal. | 15 | - | - | - | - | 8 | - |
| Phosphor Bronze | CW453K | C52100 | Bal. | - | - | - | - | - | 8 | P: 0.3 |
| Phosphor Bronze | CW451K | C51000 | Bal. | - | - | - | - | - | 5 | P: 0.2 |
| Silicon Bronze | CW116C | C65500 | Bal. | - | - | 1 | - | - | - | Si: 3 |
| Aluminum Silicon Bronze |
CW302G | C64200 | Bal. | - | - | - | - | 7.5 | - | Si: 2 |
| Cast Nickel Aluminum Bronze |
CC333G | C95800 | Bal. | 4 | 4.5 | - | - | 9 | - | - |
| Gunmetal | CC491K | C83600 | Bal. | - | - | - | 5 | - | 5 | Pb: 5 |
| Aluminum Brass | CW702R | C68700 | 78 | - | - | - | Bal. | 2 | - | As: 0.04 |
| Naval Brass | CW712R | C46400 | 61 | - | - | - | Bal. | - | 1 | Pb |
| Aluminum-Nickel- Silicon Brass |
CW700R/ Tungum®* |
C69100 | 83 | 1.2 | - | - | Bal. | 1 | - | Si: 1 |
| Dezincification Resistant Brass |
CW602N | C35330 | 62 | - | - | - | Bal. | - | - | Pb: 2 As: 0.06 |
| Manganese Bronze (High Tensile Bronze> |
CW721R | C67500 | 58 | - | 0.8 | 1.5 | Bal. | 1 | 0.7 | Pb: 1 |
| Proprietary Alloy | UR 30™ | - | 64 | - | - | - | Bal. | 0.6 | 0.6 | Various |
| Copper-Beryllium | CW101C | C17200 | Bal. | - | - | - | - | - | - | Be: 1.9 Other: 0.5 |
*Tube only
Source: Copper Development Association. Copper Alloys for Marine Environments. Publication No. 206 May 2011.
URL: http://www.copperinfo.co.uk/marine/downloads/pub-206-copper-alloys-for-marine-environments.pdf
