
1. Billet Conditioning: This process is intended for
checking the surface quality of billet and removing any defects. Shot
blast is used to remove any scale from the surface. Magnet particle
testing and visual inspection are also used to identify any defects
which must be removed using a grinder. Ultrasonic testing and dimension
and geometry checking are also applied as part of the internal quality
assurance process.
2. Reheating: The temperature within the furnace and
the duration of reheating depend on where the product will be used. To
avoid decarburization, which can affect the surface quality of the
product, a billet is pre-heated sufficiently at a low temperature before
being rolled within the reheating furnace. For this purpose, the fuel
and air ratio are strictly controlled.
3. Rolling: The temperature, draft and speed of
deformation with which the product is rolled are controlled to meet
customer requirements for material features. Further measures to ensure
the surface quality include the adjustment of roll roughness and gap,
detection of any cracks and dimension correction.
4. Cooling: Coiling temperature at the laying head, the
air flow and movement speed of the blower on the cooling bed and the
cooling speed of the insulation cover are controlled to ensure that the
product has the features required for each application. High carbon
steel Wire rods are subject to fast cooling to achieve the
microstructure required for successful drawing while low carbon steel is
subject to slow cooling to ensure that the product provides the
softness required for the customer to eliminate an annealing process.
5. Inspection: Samples are taken from the front and
rear edges of the product after rolling and cooling for testing to
identify any defects in the dimension or surface or material integrity.
Packaging and tagging are also inspected according to customer
requirements prior to shipping.