Structure and mechanical properties of T91 welded joint with low-alloy root pass

Abstract

The paper presents the results of metal science research of the T91 steel joint welded with two additional materials. The root pass was made with the additional material with its chemical composition similar to that of the 10H2M steel, and the fill pass was made with the material of the chemical composition of T/P91 steel. The examined joint was subject to heat treatment annealing 760 °C/2h. The non-destructive and the destructive tests proved that the investigated welded joint fulfilled the quality requirements at the B level and was characterised by the required or satisfactory me- chanical properties. The structural tests showed the occurrence of a single decarburised zone, its width and length be- ing of the order of several grains, between the root pass and the fill pass.

Keywords

• T91 steel
• low alloy steel
• root
• TIG