Welding deformations, stresses and translations:
- There are developed methods and algorithms for calculation of the residual local and total longitudinal, transverse and corner welding deformations, stresses and distortions.
- There are developed methods for non-destructive measurement of the residual welding stresses based on variation of the magnetic properties of the welded metal.
Resistance of the welded joints against welding cold cracks formation:
- By means of the new criteria, the resistance against cold crack formation is analyzed and assessed for a wide range of constructional steels. A program is developed for calculation of minimal temperature, needed for preliminary heating to prevent the cold cracks formation.
- A device (technological sample) is designed and manufactured for testing and quantity evaluation steel resistance against welding cold crack formation.
Residual welding stress relaxation and improvement of the safety of welded joints and constructions by local explosion effect:
- Possibilities are defined for essential improvement of some strength characteristics of the welded joints such as fatigue strength, impact strength at low temperatures, brittle fracture resistance, etc. as a result of changes in the microstructure and dislocation field in the metal during passing of welded joint detonation front. In some ferrite grains where plastic deformation is localized, twins are formed whose direction is connected with the angle at which the shock wave enters in the welded joint metal and with the direction of the reflected wave.
- Technologies are developed and implemented for reduction and redistribution of residual welding stresses by local explosion treatment of different constructions in NPP, wagon-tanks of 87m2 volume, propane-butane bottles of 40 – 120 dm volume, tanks of 10 – 25 m3 volume, pipes and pipe-lines.
Diffusion welding in vacuum of homogeneous and heterogeneous materials:
- Unit is designed for diffusion welding in vacuum of homogeneous and heterogeneous metals.
- Technologies are developed for diffusion welding in vacuum of different combinations of materials.
- There are determined the parameters of the conditions in which maximum strength is achieved for a joint of alumina ceramics and austenitic stainless steel by diffusion welding in vacuum.
- Program is developed for selection of the basic parameters of the conditions for diffusion welding in vacuum of joints of steel with aluminum ceramics.
- The effect of the main technological parameters on the quality of diffusion welded in vacuum joints of metal ceramics and mild steel is determined.
Welding of hollow components by magnet controlled arc:
- A series of machines and technologies are designed for butt welding of hollow components by magnet controlled arc
Electroslag welding in narrow interstice:
- A series of machines and technologies are designed for butt electroslag welding by strip electrode