ERW submarine pipeline steel plate coil and production process thereof

Abstract

The invention discloses an ERW submarine pipeline steel plate coil and a production process thereof, and belongs to the technical field of submarine pipeline steel. The ERW submarine pipeline steel plate coil comprises the following main components of, in percentage by mass, 0.040% to 0.070% of C, 0.10% to 0.20% of Si, 1.40% to 1.60% of Mn, 0.020% to 0.040% of Nb, 0.020% to 0.040% of V, 0.010% to0.030% of Ti, 0.08% to 0.15% of Mo, 0.020% to 0.050% of Als, less than or equal to 0.0020% of S, less than or equal to 0.013% of P, and the balance Fe and inevitable impurity elements; developing theERW submarine pipeline steel plate coil, which applies small pipe diameter ( such as phi 219.1 to phi 273.1 mm ), with very low carbon content and very low S content ( less than or equal to 0.0020%) and P content ( less than or equal to 0.013%) is carried out. Under a TMCP process system, rolling is adjusted and controlled and the cooling processes is controlled, an uniform ferrite plus pearlite structure is obtained, materials has grain size of 10 to12 grades, band structure of no more than 3.0 grades, and low non-metallic inclusions, so that the ERW submarine pipeline steel plate coil has yield strength higher than or equal to 450 MPa, percentage of elongation greater than 30%, impact energy greater than 300 J at minus 30 DEG C, and good toughness.

Description

technical field [0001] The invention belongs to the technical field of submarine pipeline steel, and more specifically relates to an ERW submarine pipeline steel plate coil and a production process thereof. Background technique [0002] ERW (Electric Resistance Welding), which means straight seam resistance welding, ERW steel pipes are mainly used to transport vapor and liquid objects such as oil and natural gas, which can meet various requirements of high and low pressure, and currently occupy a pivotal position in the field of transportation pipes in the world . However, ERW steel pipes have strict interval control requirements for yield strength and tensile strength. The tensile strength (535MPa) is 120MPa. At this time, the performance fluctuation of the product is small, and the horizontal and vertical properties are stable. For the small diameter of ERW submarine pipeline steel (such as Φ219.1~Φ273.1mm), the longitudinal yield strength of the hot-rolled coil increase...

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Problems solved by technology

[0007] Aiming at the problem that the horizontal and vertical strength of the steel pipe increases greatly after the existing ERW submarine pipeline steel pipe is made, the present invention provides a stee

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