Mechanical properties at high temperatures, the structure and metal phase composition of the welded joints for cast heat-resistant alloy 50Х32N43V5С2B2, received by using argon-arc welding

Abstract

ABSTRACT Research of the welded joints for the 50Х32N43V5С2B2 alloy received by using argonarc welding with the application of filler material with basic composition 45Х35N45С2B (Thermanit 35/45 Nb rods) is carried out. Short-term mechanical properties of welded joints in the temperature range of 20 … 1100 °C, showing their compliance with the technical documentation requirements for radiant tubes of the hydrocarbons pyrolysis furnaces, are determined. As a result of long-term strength tests at 1000 °C during the 10,000 hours it was found that the welded joint metal has a higher time indices to failure than welded joints, including both the base metal and the welding joint. Researches of the tested samples make it possible to judge about the structural stability of the welded joint metal. Researches have shown the possibility of using the developed welding technology at the manufacture of radiant tubes for pyrolysis furnace coils.