86results about How to "Reduced impact toughness" patented technology

The invention provides an X80 steel grade anti-corrosion low-temperature seamless line pipe which comprises the following components in percentage by weight: 0.08 to 0.14 percent of C, 0.20 to 0.35 percent of Si, 1.10 to 1.40 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, 0.10 to 0.20 percent of Mo, 0.020 to 0.060 percent of Al, 0.02 to 0.05 percent of Nb, 0.05 to 0.10 percent of V, 0.10 to 0.20 percent of Cu, 0.10 to 0.20 percent of Ni, less than or equal to 0.015 percent of Ti, less than or equal to 0.15 percent of Cr, 0.0015 to 0.0060 percent of Ca, less than or equal to 0.0005 percent of B, less than or equal to 0.012 percent of N, less than or equal to 0.43 percent of CEV, less than or equal to 0.23 percent of Pcm and trace amount of ferrum and impurity elements. The line pipe has the rigidity of less than or equal to 250 HV10 and grain size of more than or equal to 8 levels, and passes tests of hydrogen induced cracking (HIC) and sulfide stress corrosion (SSC) corrosion tests at the ductile-brittle transition temperature of below -60 DEG C. The line pipe has the advantages that the integral tissue of a pipe body is uniform,the equivalent carbon content is less than the that of the requirement of the American petroleum institute (API) 5L standard, the welding performance is high, the low-temperature toughness and anti-corrosion performance are excellent, the cost is low, and the requirement of users on the X80 steel grade seamless line pipe can be met completely.