Microalloyed Engineering Steels with Improved Performance – an Overview*

Microalloying elements are added to a wide range of steels for improving microstructure, properties, processing or general performance. A survey is given on the various reasons for microalloying of engineering steels. In case hardening steels microalloying improves toughness and fatigue properties mainly due to a smaller and more homogeneous prior austenite grain size. In forging steels, microalloying controls the phase transformation during cooling after forging enabling shorter process routes. Furthermore, microallying contributes to the microstructural refinement improving the balance of fatigue, cyclic behavior and strength. Recently, microalloying supports the interface engineering in air hardening medium Mn steels and prevents embrittlement.