Crack initiation steel pipe for full-scale gas bursting test of large-diameter high-grade steel gas pipeline and preparation method thereof

Abstract

The invention discloses a crack initiation steel pipe for a full-scale gas bursting test of a large-diameter high-grade steel gas pipeline and a preparation method thereof, belonging to the field of a petroleum pipeline breakage control test. The steel pipe comprises the following components by weight percent: 0.07%-0.12% of C, 1.50%-1.75% of Mn, 0.15%-0.35% of Si, less than or equal to 0.015% of P, 0.010%-0.020% of S, 0.005%-0.030% of Al, less than or equal to 0.002% of O, less than or equal to 0.00015% of H, less than or equal to 0.005% of N and the balance of Fe; and carbon equivalent is less than or equal to 0.55%, and the cold cracking sensitive coefficient is less than or equal to 0.28%. The preparation method comprises the following steps: smelting and continuously casting the raw materials so as to form a thick slab; carrying out rough rolling and precise rolling so as to obtain a hot rolled steel plate; and forming the hot rolled steel plate, then welding, and then expanding diameter so as to prepare the steel pipe, wherein the yield strength of the steel pipe is 550MPa-840MPa, the tensile strength of the steel pipe is 625MPa-990MPa, the charpy impact toughness of the steel pipe at the temperature of 0 DEG C is controlled between 100J-200J, and the fracture shearing area in a drop test is larger than or equal to 85%. The prepared steel pipe is used as the crack initiation steel pipe for the full-scale gas bursting test; and after crack initiation is carried out, the fracture is of ductile fracture topography and has no obvious fracture separation.

Description

technical field [0001] The invention relates to a steel pipe formula and a preparation method thereof, in particular to a large-diameter high-grade steel-grade gas pipeline full-scale gas cracking test steel pipe and a preparation method thereof, in particular to a steel grade with a strength level reaching X80, X90, and X100 , steel pipe outer diameter 760mm ~ 1422mm, wall thickness 12mm ~ 30mm, delivery pressure of 10MPa and above large-diameter high-grade steel gas pipeline full-scale gas cracking open steel pipe and its preparation method. Background technique [0002] With the rapid development of the large-diameter high-pressure gas pipeline industry, pipeline safety issues have attracted much attention. The long-distance expansion of ductile cracks in large-diameter high-pressure gas pipelines is the biggest threat to pipeline safety. If the pipeline is improperly designed or used, the long-distance expansion of cracks is likely to occur. In severe cases, the cracks c...

AI Technical Summary

Problems solved by technology

[0004] At present, the preparation of crack-initiating pipe sections with appropriate toughness is also an exploratory technology in the world, and there is no mature technology that can be directly applied