The weldability of low carbon high niobium steels designed for linepipe and general use within the HIPERC project

The HIPERC study was a European research project involving several steel companies and research organisations which examined the effects of alloying elements and processing conditions in low carbon (< 0.09 wt%), niobium containing (0.05 - 0.12 wt.%) steels. Laboratory-scale heats and pilot rolling trials simulating air and water-cooled plate production, as well as hot-rolled strip production, were made and the effects of C, Mn, Ni, Cu, Cr, Mo, Nb, Ti and B on transformation characteristics and temperatures of recrystallisation determined. Regression equations for the characterisation of microstructure, tensile and impact properties and for the weldability of these steels were derived. Several full commercial casts were made and processed into plate and coil-plate by three steel companies and pipe was produced from both products. The weldability of all these products was assessed and full scale fracture tests carried out. The project has shown that excellent combinations of strength, toughness and weldability can be obtained for a wide variety of applications. (AU) Copyright © 2013 Companhia Brasileira de Metalurgia e Mineração (CBMM) All Rights Reserved