The invention provides an X70-degree
large deformation resisting pipeline steel plate with excellent tenacity and a preparation method for the pipeline steel plate, and belongs to the technical field of low-carbon micro-
alloy steel. The pipeline steel plate comprises the following
chemical constituents by weight percent: 0.03 to 0.08 percent of C, 0.10 to 0.45 percent of Si, 1.40 to 1.69 percent of Mn, 0 to 0.015 percent of P, 0 to 0.005 percent of S, 0.01 to 0.06 percent of Alt, 0.01 to 0.05 percent of Nb, 0.004 to 0.014 percent of Ti, 0 to 0.008 percent of N, and 0 to 0.0002 percent of H, and further comprises one to four types of the following
chemical constituents by weight percent: 0 to 0.30 percent of Mo, 0 to 0.30 percent of Ni, 0 to 0.30 percent of Cr, 0 to 0.30 percent of Cu, andFe and unavoidable
impurity elements in balancing amount. The preparation method comprises the following steps: revolving furnace
smelting, outside furnace refining,
continuous casting, heating, controllable rolling, accelerated cooling, and the like. The pipeline steel plate has the advantages of excellent tenacity and
large deformation resistance, thereby being widely applied to land
liquefaction subsidence and ground
landslide deformation in a seismic area caused by a
permafrost as well as to pipeline
engineering such as
deep sea pipeline laying where
severe plastic deformation can be caused easily.