Production of high strength line pipe steel by Steckel mill rolling and spiral pipe forming

Since 1994, IPSCO has produced over 180,000 tons of X80 linepipe. This steel has been produced using a unique combination of electric arc furnace (EAF) melting, controlled rolling on a Steckel mill and spiral pipe-forming with double submerged arc (DSAW) welding. Each of these technologies presents unique challenges for the production of line pipe requiring high strength, low temperature toughness and weldability. Scrap-based EAF melting technology requires careful control of residual elements. Controlled rolling on a reversing Steckel mill demands relatively long rolling times that counter the achievement of fine-grained microstructures. Spiral pipe-forming requires careful control to ensure dimensional tolerances and weld quality are maintained. Nonetheless, each of these technologies offers their own efficiencies and benefits and with proper control, production of high quality line pipe is achievable in an economic manner. This paper will examine the linkage of these various operations to achieve the efficient production of high quality line pipe. (AU)