Reference number 2016-02837
Funding from Vinnova SEK 3 999 000
Project duration September 2016 - August 2019
Status Ongoing
Venture The strategic innovation programme for Metallic material
Call Strategic innovation program Metallic materials - spring 2016

Purpose and goal

In highly loaded industrial applications, it will be verified that also in steels the ternary system Fe-Si-C (3 times more Si atoms than C atoms), austempered into ausferritic microstructures, offers significantly better combinations of strength & toughness and higher abrasion resistance than conventionally hardened martensitic steels. This is done in a creative environment between companies (most mid-size) producing and using materials, as well as researchers at LTU. Previous approaches within ´superbainite´ have insufficient Si-content to provide decisive advantages.

Expected results and effects

Ovako & Smålands Steel Foundry will, as rolled bar/forgings and castings to both participating OEM and other industries, be able to offer steels with extreme mechanical & tribological performance at equal production cost vs. today´s hardened steels. The project develops material data on improved mechanics incl. fracture toughness & fatigue and tribological properties in sliding bearings & abrasive wear offered by elevated Si% of solution strengthened ausferritic steels ´SiSSASteel ´ and ductile irons ´SiSSADI ´, as well as an initially Swedish standard for ausferritic steels.

Planned approach and implementation

Initially a few small rolling ingots are cast by Småland´s Steel Foundry, forged/rolled by Ovako & austempered by Atlas Copco, followed by microscopy and mechanical & tribological characterization at LTU. Thereafter a full-sized (100 ton) rolling ingot is cast and forged/rolled to round & flat bar by Ovako, in parallel with ultra-high strength steel castings by Småland´s Steel Foundry. Throughout the project ausferritic ductile irons & steels are evaluated in prototypes by four OEM: Atlas Copco, Indexator, Olofsfors & Rototilt. Finally ausferritic steel is standardized in Sweden.

The project description has been provided by the project members themselves and the text has not been looked at by our editors.