Improving the range of grades of steel for bridge construction

Rebuilding and modernizing the Russian transportation network is essential to exploiting the natural resources of Siberia which are desperately needed to obtain hard currencies to finance further transportation infrastructure development. The construction of large bridge works which can support heav...

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Bibliographic Details
Published in:Metallurgist (New York) 2000-02, Vol.44 (2), p.94-97
Main Authors: Pemov, I F, Morozov, Y D, Mulko, G N, Shafigin, E K, Kolomiets, E K, Stepashin, A M
Format: Article
Language:English
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Summary:Rebuilding and modernizing the Russian transportation network is essential to exploiting the natural resources of Siberia which are desperately needed to obtain hard currencies to finance further transportation infrastructure development. The construction of large bridge works which can support heavy freight traffic requires use of metal superstructures whose design is crucial since it is subject to heavy dynamic and alternating loads including service temperatures below - 50 deg C and corrosion from high humidities and air pollution. Design and manufacturing requirements have been raised due to increased loads and more welded construction. It has been found necessary to employ brittle test specimens with an acute notch (to replace semicircular notch brittle testing) and it is also becoming necessary to specify the strength and toughness in the thickness direction of the rolled thickness in addition to internal continuity. To avoid premature failures it is essential to minimize the S and P content since the impact toughness of steel plates is halved by increasing the S content from 0.010% to 0.020%. Contents of both S and P should be no greater than 0.015%, 0.020% and 0.035% for class 1, class 2 and class 3. A serious problem is the relatively high carbon equivalent (0.52%) for 10KhSND steel which creates both welding quality and labor problems when the carbon equivalent is greater than 0.42%. It is expedient to reduce the contents of C, P, Ni, Al, Si and Mn and to compensate for the strength reduction by adding microalloying elements (Nb and V). An integrated technology (steelmaking, rolling, heat treatment) has been developed for NOSTA. The resultant cleaner steels (low C, S and P) have made it feasible to reduce the content of expensive and scarce alloying elements (Ni, Cr and Mn). Introduction of Cr and Ni into 10KhSNDA steel was made possible by using Cr-Ni pig iron.
ISSN:0026-0894
1573-8892
DOI:10.1007/BF02463539