The structure and properties of mixed welded joints made of X10NiCrAlTi32-21 and X6CrNiMoTi17-12-2 steels

This paper describes the welding technology applied for mixed joints of tubes made of austenitic steels in the X10NiCrAlTi32 - 21 and X6CrNiMoTi17 -12-2 grades. One made a butt joint and a multi-run joint, with the inert gas welding method and a non-consumable electrode. The mechanical properties were tested in the following scope: static tensile test, bending test from the side of the face and from the side of the root, impact test of the joint and hardness measurements. The tests were supplemented by the assessment of the macrostructure and microstructure of the joint. The performed nondestructive and structural tests did not reveal any welding imperfections, and the mechanical test results confirmed high properties of the welded joint. On this basis, the joint was classified into the "B" quality level according to PN EN ISO 5817. The mechanical and structural test results constitute the basis for qualification of the welding technology according to PN EN ISO 15614.