Air Cooling Martensites—The Future of Carbon Neutral Steel Forgings?

Abstract

The air‐hardening ductile forging steels belong to the third generation of advanced high‐strength steels and achieve their final, martensitic microstructure simply by air cooling from the forging heat. The present conference paper reviews the 15 years of development, different alloying strategies, and metallurgical throwbacks like manganese embrittlement. Furthermore, the most recent results concerning microstructure, mechanical properties, and cyclic material behavior obtained from an industrial trial melt are discussed together with the implications of these results on the carbon footprint (CF) and their impact on the resource efficiency of forged steel components. It is demonstrated that the CF of a steel product needs to be discussed on different levels, as the material‐, process‐, and product‐level contributions need to be considered. Furthermore, a case is made for new high‐strength steels in the context of circular economy, as increase fatigue resistance enables lightweighting potentials.