Ways to solve welding problems of bridge structures for arctic service

Abstract

The problems of material selection for steel bridge structures for arctic service and welding of such structures in pre-fabricated conditions and at sites are considered. The sources for the research included data on the requirements for steels for the manufacture of metal bridge structures for arctic service, the specifics of their welding, control of structure formation and mechanical properties of welded joints. The main reason for the insufficient impact strength at low temperatures is the presence of microcracks on the grain boundaries of the metal crystal structure, the cause of which is the presence of phosphorus and sulfur impurities in structural steels. To improve cold resistance properties, welding modes should be chosen in such way, that liquid metal stays for the minimum amount of time at the melting point of iron sulfide on the grain boundaries of the metal crystal structure. The necessity of engineering comparative analysis with the application of modern research methods of available methods for welding of bridge structures for arctic service is shown.