Resource efficiency gains by elimination of centre defects in long products

Purpose and goal

The project consortium analysed internal quality and productivity issues related to the production of specialty steel long products, focussing on the interaction between the cast microstructure and hot workability in bar and rod rolling. On the basis of this analysis, several countermeasures related the use of homogenizing heat treatments prior to rolling, billet/ingot internal oxidation control, and safe rolling practices were proposed and tested firstly at laboratory and pilot plant scale, and then in a large series of successful industrial trials at five works in Sweden.

Expected results and effects

From the performance analysis of the full scale trials performed in the project, three countermeasures were judged as successful, and a prototype for a new production route developed and demonstrated at full scale. Product was delivered to an end customer and tested successfully. Members of the project consortium have indicated that they will further develop this production route as a routine full scale production option for a higher productivity, and lower cost production of these types of specialty steels.

Planned approach and implementation

The project developed and tested a simplified production route for specialty long products which includes several newly developed countermeasures. This was judged successful, and although further development is required before this would be used routinely, the production route has indicatively increased productivity for this class of product by over 20% while reducing costs and increasing yield compared with the standard production route. Other countermeasures developed have more general application to a much wider range of Swedish production.