5251 is a medium strength metal known for its ductility and formability. This grade of Aluminium alloy is best known as a metal that can harden rapidly and is weldable easily.
The 5251 alloy is also popular because of its high resistance to corrosion, and is commonly used in marine, coastal environments.
You can temper 5251 into many forms, the most popular forms of 5251 are:
H22 – Work hardened and partially annealed to a quarter hard state
H24 – Work hardened and partially annealed to a half hard state
H26 – Work hardened and partially annealed to a three quarter hard state
O – Wrought and fully annealed
Circuit Board,Construction , Decoration, Boat
Description Aluminium 5251 is an aluminium magnesium manganese alloy which can be hardened by cold work: it is not heat treatable to higher strength. It is about mid way through the series of aluminium magnesium alloys for alloying content and strength, which is very similar to alloy 5052.
Corrosion Resistance 5251 has the same high resistance to general corrosion as other non heat treatable aluminium alloys. It also has the higher resistance to slightly alkaline conditions common to the 5000 series alloys. The resistance of 5251 to corrosion in marine atmospheres is excellent, exceeding that of 5005, hence the frequent use of 5251 in marine applications such as small boats and dinghies.
The corrosion resistance of aluminium alloys relies on a protective surface oxide film, which when damaged is readily repaired by the rapid reaction between aluminium and oxygen. However, the high reactivity of the base metal can give rapid corrosion if the film cannot be repaired, so aluminium alloys are not suitable for use with reducing media. 5251 can be anodised to improve the corrosion resistance by thickening the protective surface film.