The slabs are heated in a pusher furnace. After a throughput time of around three hours the slabs reach a temperature of 1100 to 1200 degrees Celsius. A process model is used to ensure uniform heating of the slabs.

The proper final temperature is important for minimising grain growth in the slabs. An additional goal of the furnace model is to control heating capacity and to minimise energy consumption.

Soaking pits are used for slabs with odd dimensions or when long heating times are required. Slabs are heated in about 6 hours and removed with a tong crane. The heating process is also aided by a computer model.