The Spartan plate mill is a quarto universal reversing mill, with automatic gauge
control, capable of producing up to 200,000 tonnes per year.
Before the finished steel plate is shipped to the customer, it goes through the following
Raw Material, Steel Slab.
Quarto plate is rolled from slab supplied by fully integrated steel mills. Spartan
holds approximately 2-3 months of slab in stock, covering all the grades and sizes
in the product range.
The majority of the slab is supplied by Metinvest along with some from West European
producers. It is shipped in to the Port of Tyne by bulk carrier and stored in the
docks, 12km from the mill.
Each individual slab is moved from the port to the plant when it is required to meet
a customer’s order. The slab is flame cut on site to the exact dimensions required
for the plate to be produced.
The cut slab is reheated in one of three natural gas fired furnaces. According to
slab size one of two batch furnaces, installed in the last 4 years, or a high capacity
multizone pusher furnace is utilised.
Once heated to the required temperature, the slabs are descaled top and bottom, using
high pressure water jets to remove scale from the surface, which is a natural byproduct
of the heating process.
Quarto Reversing Rolling Mill
The slabs can range in thickness from 300mm to 190mm. To reduce the thickness and
to match the customer’s dimensional requirements, the slabs are rolled through the
quarto reversing mill. The number of passes through the mill depends on the initial
thickness of the slabs and on the dimension of the plate required. This process is
controlled precisely by an adapted automation system. Accurate thickness tolerances
are guaranteed through a sophisticated on line laser gauging machine.
The Quarto Mill is driven by Converteam, a pair of 2.5MW induction motors installed
in 2008. These state of the art motors and control systems have facilitated much
improved productivity, output, quality and reliability for the mill.
Head & tails of the plate up to 30mm thick are cut by the hot shear. Thickness is
excess of 30mm are cut at a later stage by the on line oxy-acetylene cutter.
Hot Levellers. Hugh Smith and Sack The plate then passes through the leveling machine
while still hot, to ensure the plate meets the flatness standard required.
The plates are then held on the cooling bed to cool and are inspected for surface
quality and dimensional accuracy.
Cold Levellers. Gotha, M & N, Bronx
Additional leveling can be undertaken once the plate has cooled using the cold levelers.
Punching & Marking.
The plates are punch marked with numbers to give full traceability of the plate.
Bar code and grade/dimensions labels are fixed to the plate.
Plates from Spartan are predominantly supplied with mill edges as rolled. On request
the edges can be cut off line by an oxy-acetylene cutter to give a flat edge.
Plates up to 8m long can be heat treated using the one of two normalizing batch furnaces.
Approved contractors can heat treat plates longer than 8m as well as shot blast and
prime plates when required by customers.