Thick Hot-Rolled Steel Plate for Spiral Linepipe Having High Toughness and Strength and Method for Manufacturing the Same

摘要

The present invention relates to a high-strength high toughness hot-rolled high-strength API-X80 grade line pipe thick hot-rolled steel and a method for manufacturing the same, which are used for construction, pipelines and offshore structures, etc., having a yield strength that satisfies the API specification. The present invention is to provide a tough hot rolled steel for toughness and high strength spiral line pipe and a method of manufacturing the same.;The present invention is, by weight%, C: 0.03 to 0.10%, Si: 0.01 to 0.50%, Mn: 1.20 to 2.00%, P: 0.03% or less, S: 0.002% or less, Nb: 0.01 to 0.10%, V: 0.01 to 0.1%, Ti: 0.01 to 0.10%, Cr: 0.1 to 0.50%, Mo: 0.1 to 0.5%, Cu: 0.30% or less, Ni: 0.10 to 0.50%, N: 0.010% or less, remaining Fe and other unavoidable Impurity and the Cr, Cu, Ni, Mo, Ti, Nb, V and P;The hot-rolled hot rolled steel material for high toughness and high strength spiral line pipe which satisfies certain relations (1), (2) and (3), and a method of manufacturing the same.;API, Spiral, Pipe, High Toughness, High Strength, Low Cost