Quenched and tempered pipeline steel for X70-grade pipe pile and preparation method of quenched and tempered pipeline steel

Abstract

The invention discloses quenched and tempered pipeline steel for an X70-grade pipe pile and a manufacturing method of the quenched and tempered pipeline steel. The quenched and tempered pipeline steel is prepared from the following components, by weight percentage, 0.12%-0.16% of C, 0.25%-0.40% of Si, 1.45%-1.60% of Mn, smaller than or equal to 0.008% of P, smaller than or equal to 0.003% of S, 0.03%-0.05% of Nb, 0.015%-0.030% of Ti, 0.030%-0.050% of V, 0.15%-0.25% of Cr and the balance Fe and inevitable impurity elements. A manufacturing method comprises the following steps of KR, converter smelting, LF, RH, CCM, casting blank slow cooling for 48 h, plate blank heating, high-pressure water descaling, rough rolling stage, finish rolling stage, straightening, cooling, shot blasting, quenching, tempering and straightening. The alloy is low in cost and good in welding performance, the impact energy at 0 DEG C is larger than 150 J, and the alloy has the advantages of being low in cost, high in strength and resistant to tearing.

Description

technical field [0001] The invention relates to the technical field of production of medium-thick steel plates for pipe piles, in particular to a quenched and tempered X70-grade pipeline steel for pipe piles and a preparation method thereof. Background technique [0002] As a clean offshore energy, wind power has the advantages of low cost, high energy efficiency, and sustainability. As the bearing structure of wind turbine bases, pipe piles are subject to complex forces in harsh environments such as nearshore and deep sea. Thick, high strength, tear resistance and so on. Patent No. 201610487992.4 discloses a X70 grade thick specification pipeline steel composite plate and its manufacturing method, which is characterized in that the thickness specification is 25-45mm, and the high and low temperature ductile pipeline steel is produced by composite billeting. The production process is complicated and the thickness specification It cannot meet the application requirements of ...

AI Technical Summary

Problems solved by technology

Patent No. 20130489482.7 discloses a steel for corrosion-resistant bridge pipe piles and its production method. It belongs to Q345B or Q345C grade coiled pipes. The specification is usually less than 30mm, which cannot meet the application of pipe piles in special environments.

Patent No. 201611057154.X discloses an extra-thick EH36 steel for wind power pipe piles and its preparation method, which has the characteristics of lamellar tear resistance, low temperature resistance and corrosion resistance. Although the specifications have been greatly expanded, it has certain Low temperature toughness, but low strength

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