Controlled hot forming of heat treatment steel grades in the intercritical (γ–α) region

Thermomechanical treatment with its specific methods has contributed substantially to the improvement of product quality and the rationalisation of production. The economic advantages of thermomechanical treatment are obvious; however, an analysis of the current state of knowledge shows that the potential of this method has not yet been exhausted. In this context, controlled hot forming in the two-phase region is a very promising trend. The first part of this work was dedicated to the microstructural formation, deformation behaviour and deformability in the two-phase region. The investigations aimed at clarifying the differences between hot forming in the austenite region and the two-phase region, as well as explaining and illustrating special phenomena occurring during hot forming in a region with two major phases. The second focus of this article is the limit values of rolling technologies. The microstructural features and property combinations obtained were assessed by extensive metallographic and material tests. Thermomechanical treatment in the two-phase region enables the production of advantageous property combinations.