Purpose. The technology makes it possible to increase the resistance of welded joints against the formation of cold cracks, significantly reduce the temperature of preliminary and concomitant heating and offer an energy-saving post-weld heat treatment mode, ensuring high mechanical properties of welded joints of cavitation-resistant martensitic steels.
Specifications. The technical characteristics of welded joints of modified cavitation-resistant martensitic steels of type 03Х13Н4, made using the developed technology, fully meet the requirements of the instructions “GTI – 407 – 2005. Technical requirements for welded-cast impellers of radial-axial hydraulic turbines.” and ASTM INTERNATIONAL. “ASTM A743/A743M – 2013a: Standard Specification for Security, for General Use.”
Application area. Power engineering, thermal and nuclear energy, chemical construction.
Advantages. The developed new technology makes it possible to increase the resistance of welded joints against the formation of cold cracks, significantly reduce the temperature of preliminary and concomitant heating and offer an energy-saving post-weld heat treatment mode, ensuring high mechanical properties of cavitation-resistant martensitic welded joints.
Technical and economic effect. Scientifically based provisions and technological measures have been developed to increase the stability of welded joints by 50% against the formation of cold cracks, to significantly reduce the temperature of preliminary and accompanying heating – an oxyfluoride coating of electrodes has been created, which ensures that the carbon content in the deposited metal is limited to 0.02%. and diffuse hydrogen content up to 3 cm3/100 g of metal.
Description. The technology of welding and cavitation-resistant steels makes it possible to increase the resistance of welded joints against the formation of cold cracks, significantly reduce the temperature of preliminary and concomitant heating and offer economic parameters for post-weld tempering of welded joints of cavitation-resistant martensitic steels. Based on the results obtained, a standard technology for manual and mechanized welding of thick-walled pipe joints of steel 03Х13Н4Д has been developed.