Properties and Structure Formation in Welded Joints when Welding Steel X65 by Different Technologies

Resumo

Use of contemporary welding technology for welding gas pipes based on specifications of standard documentation makes it possible to obtain sufficiently high quality welded joints providing good reliability, although research in the field of welded point structure formation and properties remains important. Welding technology for microalloyed steel of pipe designation is studied. Properties and structure formation in pipe welded joint metal with welding using different technologies are studied. It is shown that depending on welding technology for steel X65 there is a change in the ratio of phases, contamination with nonmetallic inclusions, and weld metal fatigue strength throughout the whole volume of a weld. It is established that less nonmetallic inclusion contamination through the weld depth and optimum mechanical properties are observed with pipe welding by STT + IPA technology.