Iron, coke and input materials are needed to produce steel.  Iron ore is delivered to the steel plants in Luleå and Oxelösund in the form of ore pellets from LKAB's ore field in Norrbotten.

Coke is produced in SSAB's own coking plants from coal which is imported from around the world.
 

In the coking plant, the coal is heated up for 17 hours and approximately one quarter becomes gas and the remainder becomes coke.  Most of the gases are used as energy in SSAB's own processes, with the remainder being used in municipal district heating networks.

Ore pellets, coke and input materials, including lime, are continually added and mixed in the upper part of the blast furnace.  In the furnace, hot metal and slag are formed.  The slag binds contaminants and is removed from the iron during tapping.

The hot metal is transported to the steel mill, where it is purified of sulphur and coal. Approximately 20% scrap metal is added in order to cool the steel and as additional steel.  SSAB is Sweden's largest consumer of recycled scrap (797 ktonnes 2007). 

Various alloys are then added in order to endow the steel with the correct qualities.

The liquid steel is then cast into steel slabs in the continuous casting.  The steel is tapped in a casting housing and subsequently in the cast iron mould.  The steel string is cooled and hardened as it is drawn down in the casting arch, and subsequently cut into determined lengths and marked.

The slabs are heated up in slab furnaces to approx. 1,200 degrees in order to allow for processing in the rolling mill.

When the slabs are heated, the red hot slabs are rolled in the four-high rolling mill into plate with thicknesses of between 3 and 155 mm.

After quenching, the plate must undergo heat treatment in which the plate is heated up again and quenched in order to be endowed with the desired strength and toughness.

Finally, the plate undergoes surface treatment in which the plate is blasted and painted as corrosion protection and a basis for final painting.

 

Slabs are transported to the rolling mill in Borlänge from the steel mills in Luleå and Oxelösund.

All slabs that reach the Strip Products Division in Borlänge pass through the hot rolling mill.  There, the slabs are heated to approximately 1,200 degrees in slab furnaces.  The slabs are then rolled from a thickness of 220 mm to between 1.8 and 16 mm.  The rolling takes place in various stages in which each stage is of the utmost importance for the final quality of the material.  A part of the hot-rolled sheet is sold directly to the customer and a part undergoes further processing. 

The next stage in the process is pickling.  In the pickling, the steel strip is washed with hydrochloric acid in order to remove the oxide scale that is formed during the hot rolling.  Part of the pickled material is sold as high-strength hot-rolled sheet, while the remainder undergoes cold rolling.

In the tandem rolling mill, the strip is cold rolled to the final thickness.  The reduction is achieved through high pressure between the rollers and through draw between the various pairs of rollers.  The maximum strip width is approx. 1,550 mm and the minimum strip width is 0.33 mm.

In order to achieve a formable product after cold rolling in the tandem rolling mill, the sheet must be annealed, heat processed.  This is done either in the continuousannealing line in which the continuous heating process lasts 15 minutes.  Another method of heat treatment of sheets is in a bell furnace, in which sheet rolls are annealed individually.  The strip rolls are stacked up in an annealing hood in which shield gas is circulated and a furnace hood is placed in top.  The bell furnaces are used for heat treatment of thicker materials and materials that must not be hardened in the heating process.  The process takes between three and six days.

A part of the cold-rolled sheet is metal coated in order to achieve a corrosion-resistant product.  Sheet that is to be organic-coated must also first coated with metal in order to achieve a surface that withstands the demands of the organic coating lines.

The metal-coated sheet is painted in the organic coating line.  It is painted partly for aesthetic reasons and partly to achieve a longer lifespan.