This specification defines the requirements of aluminum coatings on flat products of steel. Two types of aluminum coatings are specified:

Hot-dip Aluminum Coating Continuous dipping into molten aluminum gives an aluminum coating on both sides of the flat product after a corresponding pre-treatment to increase the heat- and corrosion resistance.

Roll Cladding Continuous roll cladding of an aluminum layer gives an aluminum coating on both sides of the flat product after corresponding pre-treatment to increase the heat- and corrosion resistance.

It is possible to obtain different coating thicknesses on each side.

Welded pipes manufactured from aluminum coated flat products are also covered by this specification.

Material Description.

Hot-dip Aluminum Coating The aluminum coating comprises of 3 layers. Initially on the base metal a thin layer in which aluminum exists in solid solution, is formed. On this an iron-aluminum alloy layer (diffusion zone) is joined which because of its brittleness shall be limited in thickness:

Restrictions:

Sheets of (0.5...1.0) mm thickness: Diffusion zone 35 % max. of total thickness.

Sheets > (1.0...2.0) mm thickness: Diffusion zone 45 % max. of total thickness.

This diffusion zone then is covered by the outer layer corresponding to the composition of the aluminum bath.

Roll Cladding The rolled-on pure aluminum respectively aluminum-silicon-alloy layer is mechanically clamped with the base metal. A diffusion zone does not originate.

Material Identification. See coding system paragraph 7.

Cross-Reference of Replaced Specifications. Subparagraphs were not applicable.

Symbols. Not applicable.

Typical Application. Not applicable.

Remarks. Not applicable.