Structure and crystallization of metals and their alloys are considered. Elements of the general theory of metal alloys are described. Modern methods for studying the structure and properties of metals and alloys are described. The influence of technological processes and operating conditions on the structure and properties of metals and alloys is shown. Heat treatment bases are given. Basic information on special steels and non-ferrous metals and their alloys is given. Much attention is paid to the issues of long-term strength and operational reliability of materials of power equipment and welded joints.