Non-thermally hardened aluminum in the Eurocode 9
Aluminum alloys Eurocode 9
The European standard EN 1999-1-1 part of a series of standards EUROCODE 9 (Eurocode 9). It defines the common rules and standards for the application of aluminum alloys in structures.
Eurocodes 9 includes recommendations for use in construction:
1) wrought heat-hardening aluminum alloys;
2) wrought thermally unhardened aluminum alloys;
3) cast aluminum alloys, as a thermally hardenable, and thermally hardened.
Below we consider the recommendations of the Eurocode 9 by Application deformable aluminum alloys, which are not hardened by heat treatment.
Wrought alloys are thermally neuprochnyaemye
The following alloys from the 5xxx series are used from deformable thermally non-strengthened aluminum alloys in construction: 5049, 5052, 5454 and 5754. In other deformable thermally neuprochnyaemymi aluminum alloys, which are used in construction to less loaded structures, are alloys 3004, 3005, 3103 and 5005.
The chemical composition of alloys series 3xxx, 5xxx and 8xxx
Table 1 presents the chemical composition of wrought aluminum alloys thermally neuprochnyaemyh, that Eurocode 9 Recommended for use in structures.
Table 1 - Chemical composition of the alloys of the series 3xxx, 5xxx and 8xxx
The strength of the 3xxx series alloys, 5xxx and 8xxx
The tables 2 and 3 the characteristic (minimum) strength properties of extruded profiles and sheet metal from aluminum alloys of the 3xxx series are presented, 5xxx and 8xxx, including, a welding heat-affected zone. For complete information about the strength properties of aluminum alloys look. the full text of the European standard EN 1999-1-1:2007.
Table 2 - Mechanical properties of profiles of the 5xxx series alloysTable 3 - Mechanical properties of sheet metal series alloy 3xxx, 5xxx and 8xxxAluminum alloys 5049, 5052, 5454 and 5754
Aluminum alloys 5049, 5052, 5454 and 5754 suitable for use in welded and non-welded construction structures, as well as in structures with mechanical connection at moderate operating voltages. These alloys are ductile in the annealed condition, but quickly lose their plasticity when cold forming, for example, bending, stamping, rolling. They are well welded by methods MIG and TIG. They have very good resistance to corrosion, particularly in the marine atmosphere.
These alloys are mainly used in the form of a rolled product, as even a moderate content of magnesium extruded profiles allows only a simple cross-section.
These alloys respond well to machining in the cold-worked condition. Alloy 5154 is the most durable alloy of the 5xxx series, which has no problems with the intergranular corrosion and stress corrosion.
Aluminium alloy 5083
Alloy 5083 alloy is the strongest of thermally alloys neuprochnyaemyh, which are used in construction. It has good properties in welded structures, and good corrosion resistance. It has high ductility and ability to forming in the annealed condition. Loses ductility as a result of cold plastic working and becomes solid and maloplastichnyh.
Intergranular corrosion of alloy 5083
Alloy 5083 in all its states (cold-worked), especially in the states of H32 and N34, may be susceptible to intergranular corrosion, which in some circumstances may develop in stress cracking during continuous load. In order to minimize this phenomenon developed special state N116. Nonetheless, the use of this alloy is not suitable under the conditions, when the material may undergo a strong plastic deformation and / or at a temperature above 65 oC. In such cases it is recommended to use instead Alloy 5754.
alloy welding 5083
Alloy 5083 suitable for MIG welding and TIG. When welding alloy 5083 in the cold-worked condition strength properties welding heat affected zone is reduced to a level, characteristic of the annealed condition.
Aluminum alloy products 5083
alloy 5083 make plates (thick sheets), sheets, profiles simple form, seamless pipes, cold drawn tubes and forgings. Due to the large content of the magnesium alloy difficult for pressing. Therefore, the assortment of alloy extrusions 5083 limited to relatively thick solid profiles and seamless single cavity hollow profiles (pipes).
Mechanical treatment alloy 5083
Alloy 5083 easily machined by cutting in all states.
Aluminum alloys 3004, 3005, 3103 and 5005
alloys 3004, 3005, 3103 and 5005 used mainly in the form of sheets. These alloys slightly stronger technical grades of aluminum, have a high plasticity, good weldability and good corrosion resistance.
Aluminum Alloy 8011A
Alloy 8011A belongs to the group of alloys AlFeSi. This alloy has long been used as a material for packaging. It is becoming more widely used in the construction industry, especially in the construction of building facades.
Source: EN 1999-1-1:2014