Specifications of TFS (ECCS)
Specifications of TFS (ECCS)
The TFS are specified as per the steel base, extent of tempering, the coating weight, annealing method and the surface finish.
The base steel is continuously cast and aluminium killed. The base steel can be single reduced or double reduced. The base steels are of the following three types.
- Type MR – These base steels are low in residual elements and have good corrosion resistance properties. These steels are widely used in general applications
- Type L – In this type the base steel has extremely low residual elements (Cu, Ni, Co and Mo). These steels have very good corrosion resistance to certain types of food products
- Type D – In D type aluminium killed base steel is used. These types are used in applications involving deep drawing or other types of severe forming that tend to give rise to Lueder’s lines
TFS is produced with the minimum and maximum average coating weights for metallic chromium layers of 50 mg/Sq m and 150 mg/Sqm respectively and the minimum and maximum average coating weights for chromium oxide layers of 5 mg/Sq m and 35 mg/Sqm respectively. TFS is normally produced in coil form in thickness ranges of 0.15 mm to 0.60 mm and width range of 700 mm to 970 mm. TFS is also being supplied in sheet from 508 mm to 1050 mm.
TFS is produced in the following surface finishes.
- Bright – in this type of finish the surface roughness is aimed at o.25 Ra. Bright finishes are normally for general use.
- Stone – In this type of finish the surface roughness aimed is 0.40 Ra. This type of finish makes printing and can making scratches less conspicuous.
- Matte – In this type of finish the surface roughness aimed is 1.00 Ra. This is dull type of finish and mainly used for making crowns.
- Silver – This type of finish is also called satin finish. This is rough dull finish mainly used for making artistic cans
The temper grades of TFS are as follow. Hardness values are given in HR 30 T. When the tinplates are produced from continuous annealed material then the symbol of CA is added to the temper grade such as T-5 CA
Single reduced
- T-1 temper grade – It has hardness value of 49 +/- 3. It is used in applications involving deep drawing that require large flexibility.
- T-2 temper grade – It has hardness value of 53 +/- 3. It is used in application that need moderate drawability and some stiffness
- T-2.5 temper grade – It has a hardness value of 55 +/-3. It is used in application that requires the drawability of T-2 temper grade in combination with the stiffness of t-3 temper grade
- T-3 temper grade – It has a hardness value of 57 +/-3. It is used in application that requires stiffness to prevent buckling
- T-4 temper grade – It has a hardness value of 61 +/-3. It is used in application that requires large stiffness such as can ends and crowns etc
- T-5 temper grade – It has a hardness value of 65 +/-3. It is used in application that requires very good buckling resistance
Double reduced
These are thin steel materials with high strength and produced by cold reducing the steel material after the process of cold reducing and annealing.
- DR -8 temper grade – It has a hardness value of 73 +/-3. It is used in application that requires stiffness and strength.
- DR-9 temper grade – It has a hardness value of 76 +/-3. It is also used in application that requires stiffness and strength.
- DR -9 M temper grade – It has a hardness value of 77 +/-3. It has similar application as DR 9.
- DR – 10 temper grade – It has a hardness value of 80 +/-3. It is used in special application that requires strength.