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Ch06-H8070.fm Page 53 Wednesday, October 18, 2006 8:03 AM
Aluminium Alloy 53
TABLE 6.1
Alloying elements

Element 5083 5086 6061 6082

Copper 0.10 max 0.10 max 0.15–0.40 0.10 max
Magnesium 4.0–4.9 3.5–4.5 0.8–1.2 0.6–1.2
--- ใช้เพื่อการศึกษาเท่านั้น---
Silicon 0.40 max 0.40 max 0.4–0.8 0.7–1.3
Iron 0.40 max 0.50 max 0.70 max 0.50 max
Manganese 0.4–1.0 0.2–0.7 0.15 max 0.4–1.0
งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
Zinc 0.25 max 0.25 max 0.25 max 0.20 max
Chromium 0.05–0.25 0.05–0.25 0.04–0.35 0.25 max
Titanium 0.15 max 0.15 max 0.15 max 0.10 max

Other elements
each 0.05 max 0.05 max 0.05 max 0.05 max
total 0.15 max 0.15 max 0.15 max 0.15 max

strength than that of the non-heat treated alloys. Since the material is heat
treated to achieve this increased strength subsequent heating, for example
ึ
welding or hot forming, may destroy the improved properties locally.
Aluminium alloys are generally identified by their Aluminium Associa-
tion numeric designation. The 5000 alloys being non-heat treated and the
6000 alloys being heat treated. The nature of any treatment is indicated by
additional lettering and numbering. Lloyds Register prescribe the following
commonly used alloys in shipbuilding:

5083-0 annealed
5083-F as fabricated
5083-H321 strain hardened and stabilized
5086-0 annealed
5086-F as fabricated
5086-H321 strain hardened and stabilized
6061-T6 solution heat treated and artificially aged
6082-T6 solution heat treated and artificially aged

RIVETING Riveting may be used to attach stiffening members to light
aluminium alloy plated structures where appearance is important and dis-
tortion from the heat input of welding is to be avoided.
The commonest stock for forging rivets for shipbuilding purposes is a
non-heat treatable alloy NR5 (R for rivet material) which contains 3–4
per cent magnesium. Non-heat treated alloy rivets may be driven cold or
hot. In driving the rivets cold relatively few heavy blows are applied and the
rivet is quickly closed to avoid too much cold work, i.e. becoming work