Aluminum Coated Steel

3. Aluminum coated steel, like the other coated steels, provides a corrosive protection to the steel sheet. There are some additional benefits that we will see below also. The aluminum protective coating is applied in several different ways including hot dipping, electroplating thermal spraying and power coating with subsequent heating to fusion. In addition, a subsequent temperature diffusion treatment can be applied to the coating as well. We will consider only the hot dipped coating and the subsequent diffusion coating as these are the most prevalent.Aluminum coated steel, like the other coated steels, provides a corrosive protection to the steel sheet. There are some additional benefits that we will see below also. The aluminum protective coating is applied in several different ways including hot dipping, electroplating thermal spraying and power coating with subsequent heating to fusion. In addition, a subsequent temperature diffusion treatment can be applied to the coating as well. We will consider only the hot dipped coating and the subsequent diffusion coating as these are the most prevalent.

4. [Aluminum Coated] Aluminum coated steel is produced by hot-dip coating cold rolled sheet steel on continuous lines. It provides a material with the superior strength of steel and the surface properties of aluminum. There are two types as illustrated here. Type 1 contains up to 8% Si in the coating and finds particular use for elevated temperature oxidation; and type 2 is essentially commercially pure aluminum coating. [Aluminum Coated] Aluminum coated steel is produced by hot-dip coating cold rolled sheet steel on continuous lines. It provides a material with the superior strength of steel and the surface properties of aluminum. There are two types as illustrated here. Type 1 contains up to 8% Si in the coating and finds particular use for elevated temperature oxidation; and type 2 is essentially commercially pure aluminum coating.

5. This is a cross section of a type 2 (pure aluminum) hot dipped aluminum coating. Note that the pure aluminum is on the top. Some darker spots of aluminum-iron inter-metallic can be seen in this aluminum. The middle region is an iron-Aluminide inter-diffusion phase. And the iron is at the bottom.This is a cross section of a type 2 (pure aluminum) hot dipped aluminum coating. Note that the pure aluminum is on the top. Some darker spots of aluminum-iron inter-metallic can be seen in this aluminum. The middle region is an iron-Aluminide inter-diffusion phase. And the iron is at the bottom.

6. Typical Applications of Coated Steels Aluminum Coated Automotive exhaust systems The aluminum coated steels find a lot of use in the manufacture of automotive exhaust systems.The aluminum coated steels find a lot of use in the manufacture of automotive exhaust systems.

7. The diffusion coating is produced by post-coating anneal to promote interdiffusion of the aluminum into the steel. No free aluminum remains on the surface, but a complex diffusion zone of iron-aluminum inter-metallic compounds is formed.The diffusion coating is produced by post-coating anneal to promote interdiffusion of the aluminum into the steel. No free aluminum remains on the surface, but a complex diffusion zone of iron-aluminum inter-metallic compounds is formed.

8. The diffusion aluminized coating can be applied to a range of materials as seen in this table. Note the uses of the diffusion aluminized carbon steels.The diffusion aluminized coating can be applied to a range of materials as seen in this table. Note the uses of the diffusion aluminized carbon steels.

10. The table here list some observations about the spot welding of the hot dipped aluminum coated steels. Because of the aluminum, the currents are higher than uncoated steel, the silicon free coatings with the somewhat lower electrical resistance are the highest current; electrode forces are grater and weld time longer. Somewhat more electrode wear is observed than with the zinc coated galvanized steels.The table here list some observations about the spot welding of the hot dipped aluminum coated steels. Because of the aluminum, the currents are higher than uncoated steel, the silicon free coatings with the somewhat lower electrical resistance are the highest current; electrode forces are grater and weld time longer. Somewhat more electrode wear is observed than with the zinc coated galvanized steels.

11. This table lists some nominal parameters for welding the hot dipped aluminized steels.This table lists some nominal parameters for welding the hot dipped aluminized steels.

12. These are some observations regarding projection welding of the hot dipped aluminized steels.These are some observations regarding projection welding of the hot dipped aluminized steels.

13. These are observations for seam welding of the hot dipped aluminized steels.These are observations for seam welding of the hot dipped aluminized steels.

14. These are some observations for the ERW and High Frequency welding of hot dipped aluminized steel.These are some observations for the ERW and High Frequency welding of hot dipped aluminized steel.

16. The resistance of the diffusion treated aluminized steels is considerably higher than the non-diffusion transformed alloy layer present in the diffusion aluminized steels. Because of this, the welding parameters are close to those of the uncoated steel. There is one exception, aluminum in the solidified weld metal can cause embrittlement.The resistance of the diffusion treated aluminized steels is considerably higher than the non-diffusion transformed alloy layer present in the diffusion aluminized steels. Because of this, the welding parameters are close to those of the uncoated steel. There is one exception, aluminum in the solidified weld metal can cause embrittlement.