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.

Thermodynamic Prediction and Experimental Verification of Transformation‐Induced Plasticity/Twinning‐Induced Plasticity Effects in Advanced Low‐C High‐Mn Steel at Different Deformation Temperatures

“…[1,2] The application of highstrength steels for automotive body parts will allow to lower the total mass of the vehicle and therefore they will contribute to reducing fuel consumption and the negative impact on the environment. [3] Beneficial mechanical properties of high-Mn steels are attributed to specific deformation mechanisms, which occur beside dislocation slip-transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP). The ε hexagonal or α 0 body-centered martensite plates and mechanical twins act as strong barrier for dislocation motion.…”

Power Density Analysis of Wind Turbine Main Bearing Units by Holistic Optimization of Material, Manufacturing and Design of the Main Shaft

“…However, their applicability for large wall thicknesses is questionable, as they were designed for automotive applications. For small components, significant reductions in the product's carbon footprint were achieved [6], increasing their sustainability [7].…”

Influence of Transformation Temperature on the High‐Cycle Fatigue Performance of Carbide‐Bearing and Carbide‐Free Bainite

“…The development of new steels with good mechanical properties and high‐fatigue resistance is critical for various industries because it improves the longevity and reliability of structures and components, which consecutively increases the circularity of the steel industry. [ 1 ] Bainitic steels with cost‐effective alloying concepts have attracted significant research attention to fulfil the requirements of many industrial applications. The performance of bainitic steels is highly related to the microstructural constituents and their morphology, which can be tailored by the chemical composition and processing parameters.…”