The technique allows to predict crack formation during heat treatment of welded joints. It has studied how chemical activism of flux influences and their mixtures on the properties of the weld metal at electroslag welding. It has been shown that increasing the chemical activity of the flux by increasing the silica content therein to 40% (mixture of fluxes ОФ-6 and AН-8) in the weld metal increases the proportion of readily deformable nonmetal oxide inclusions. This leads to an increase in the plastic properties and deformation capacity of the weld metal during welding stresses relaxation and eliminates the risk of a weld is executed electroslag welding reheat cracking.

Keywords: Welded joints, electroslag welding, chemical activism of flux, structure and mechanical properties, relaxation process of welding stresses, reheat cracking.

  Prospects are discussed of interorbital transportation vehicles based on reusable space tugs with nuclear electric rocket propulsion for spacecraft delivering to the high orbits. The potential advantages of this kind of tugs are demonstrated comparing with the traditional spacecraft launch technologies. The issues of the nuclear interorbital tugs development are examined with the special attention towards the baseline information uncertainty, as well as of the nuclear space tugs ground processing considering requirements of the nuclear and radiation safety.

Keywords: Geostationary orbit, spacecraft, interorbital space tug, parametric optimization, radiation safety, upper stage, interorbital transportation means, nuclear electric rocket propulsion, power and propulsion system.

Information about authors of issue №4 (2011)

Keywords: authors