Semenov V. Increasing of efficiency production of heavy machine-building large details by electroslag welding

The object is processes of the structural states and service properties forming of machine-building large constructions welded joints, made with the ESW use. The subject is the welded joint tensely-deformed state forming mechanism in the ESW conditions. The purpose is machine-building large products with the set properties fabrication technology development on the basis of scientific and methodological ESW fundamentals development. Methods are calculation and experimental researches of process ESW, mathematical and physical modeling, electronic fractography and roentgenstructural analysis. Results - hot cracks formation reasons in a nearweld area and weld are stated; a vacuum casting of billets of CrNiMo steels increasing nearweld area impact strength on 30 % due to includings decrease and gases and preventing hot cracks formation in it is proved; the rise of Cr maintenance to 2 % (mass) in the weld metal of these steels promoting its resistibility criterion to hot cracks formation is firstly stated; the express method of steels resistibility estimation to cold cracks formation is developed; the optimum thickness plating layer and thermoplastic treatment are stated; the complex of technological recommendations of heavy engineering machine-building large constructions ESW is developed and introduced. Purview - machine-building.