Title: Weldability of high-strength microalloyed steel S460M
Abstract: The structural steels of strength class S350 and higher are widely used in manufacture of metal structures of different purpose.Their application allows significant reducing the total metal consumption of structures as compared to the products of steels of grades St.3 and 09G2S.In the present work the influence of welding thermal cycles on the properties and structure of HAZ metal, resistance of joints to cold crack formation is considered.The selection of welding consumables for steels of strength class S490 was justified and the change of mechanical properties of welded joints was analyzed.It was revealed that with increase in the rate of cooling the HAZ metal of model specimens-simulators, the strength characteristics increase, and the ductile ones decrease.Thus, the values of impact toughness are sharply reduced at the cooling rate of 3 °C/s.It is possible to increase greatly the resistance to cold crack formation in technological samples of steel S460M at the increased content of diffusion hydrogen in the deposited metal by decreasing the value of residual stresses in welded joints to the level not exceeding 0.5s y of steel (≤235 MPa).13 Ref., 1 Table, 9 Figures.K e y w o r d s : high-strength steel,