Keyword: «residual welding stresses»

The features of the stress state, physical-mechanical and structural properties of welded joints of structural steels 09G2S and St3sp, made at low climatic temperatures, are studied. Welded samples were obtained by manual arc welding using domestic electrodes UONI-13/MOROZ, HOBEKS-K-54, LB 52TRU. During the research, pulsed arc welding was tested in comparison with the traditional method of direct current welding. When welding in the cold, an increase in the level of tensile residual welding stresses by an average of 40 ... 50% is observed compared with welding at room temperature. Features of the structure and mechanical properties during welding at negative temperatures are revealed.

Examples of destruction of welded joints of sections of main gas pipelines in Yakutia under the influence of fields of residual welding stresses are considered. The results of experimental studies of residual stress fields of welded joints of plates made by arc welding under conditions of low climatic ambient temperatures are discussed. The mechanism of the influence of residual stresses on the occurrence of additional plastic deformations in the zones of welded joints after welding under conditions of low climatic temperatures is presented.