Study of the structure of the 09G2S grade steel welded joints performed by welding at subzero temperatures

The specific features of the building of construction for responsible purpose in the conditions of the North are connected with the need to carry out welding works at negative ambient temperatures. In this regard, the issue of assessing their impact on the structure of welded joints is relevant. For research, plates of 09G2S steel, 12 mm thick, were welded. Plates with dimensions 200x300x12, bevel angle of edges (25 2), were assembled butted with a gap of 1.6 mm. Welding was carried out in three passes using two different electrodes with a diameter of 3.0 mm for forming the root layer and 4.0 mm for forming the filling and facing layers. The research article investigates the heat-affected zone (HAZ) microstructure of welded joints obtained by manual arc welding at an ambient temperature of + 20 degrees C and 45 degrees C. The features of the ambient temperature influence on the HAZ microstructure of 09G2S grade steel welded joints are revealed. (C) 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers