Preface -- The general classification scheme of boronizing -- Components and phases in systems a boron-iron and a boron-carbon-iron -- The phase equilibrium diagram of binary system iron-pine boron -- The multicomponent phase equilibrium diagrams used at boronizing steels and alloys -- Plasticity – a durability basis boronized layers -- Formation conditions boride and boronized the layers, defining their plasticity -- Ways of decrease in fragility boronized layers and the parameters of technological process defining their plasticity -- Composite structure – a plasticity basis of boronized layer -- Interrelation of plasticity boronized layers with the mechanical and working properties boronized steels -- Modeling of process of formation diffusive boronized layers and their wear resistance -- Perspective technologies of boronizing, providing the raised plasticity of layers -- Application of processes boronizing in the industry for treatment of details and tools.