This workshop is the fourth meeting convened by some of the scientific organizers and devoted to the "Ab initio description of Iron and Steel". The previous three workshops were carried out in 2006, 2008 and 2010 also at Ringberg castle, with a focus on thermodynamics, magnetism and mechanical properties respectively. These events gave rise to a lot of stimulating discussions on recent results and scientific concepts. At the same time they served as an excellent opportunity for young researchers to obtain a high-quality introduction into the field. The present seminar addresses once more the major topic "Ab initio description of Iron and Steel", but with a focus on "Thermodynamics and Kinetics".