Microstructure and Properties of an X80 Pipeline Steel Manufactured by Untraditional TMCP

Based on C-Si, low Mn and S chemical composition, via untraditional TMCP, which adopts upper finish rolling temperature, ultra fast cooling rate after rolling, and via traditional TMCP, X80 pipeline steels were produced and studied. Microstructure obtained by the untraditional TMCP mainly consists of fine and uniform acicular ferrite with dispersed precipitations. Steel with the microstructure has optimum strength-toughness value and high HIC resistance. This technology can alleviate the load of rolling mill, insure the stabilization of processing and save energy to play important roles in sustainable developments. With approximate processing parameters, properties of the steel by untraditional TMCP are better than those of the steel by traditional TMCP.