Thin-gauge X70M hot-rolled steel plate for gas transmission longitudinal welded pipe and manufacturing method

A technology of X70M and hot-rolled steel plates, which is applied in the field of high-strength X70M hot-rolled steel plates for natural gas pipelines and its manufacturing, can solve the problems of poor uniformity of steel plates, high rolling resistance, and low production costs, and achieve optimized thickness and improved The effect of starting rolling temperature and increasing reduction

CN112981258AActive Publication Date: 2021-06-18ANGANG STEEL CO LTD
10 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2021-06-18

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention relates to a thin-gauge X70M hot-rolled steel plate for a gas transmission longitudinal welded pipe and a manufacturing method thereof. The steel plate comprises the following chemical components in percentage by weight of 0.05%-0.09% of C, 0.10%-0.35% of Si, 1.50%-1.80% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.04%-0.09% of Nb, 0.008%-0.0250% of Ti, 0.015%-0.045% of Al, less than or equal to 0.4% of Cr, 0.020%-0.06% of V, 0.0041%-0.006% of N and the balance of Fe and inevitable impurities. The produced steel plate is suitable for manufacturing the X70M longitudinal welded pipe for a natural gas conveying pipeline with the pipe diameter being phi 1422 mm and the wall thickness being 10-18 mm.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the technical field of low-carbon micro-alloy steel production, in particular to a pipe diameter of A high-strength X70M hot-rolled steel plate for a natural gas transmission pipeline with a wall thickness of 10-18 mm and a manufacturing method thereof. Background technique

[0002] Pipeline transportation is the most economical, most convenient and most important transportation method for long-distance natural gas transportation. In order to reduce the construction investment and operation and maintenance costs of long-distance natural gas pipelines and improve transmission efficiency, long-distance oil and gas pipelines have always been developed in the direction of large diameter and high pressure; at the same time, in order to ensure the economy and safety of their service, some branch lines The thickness of the project steel pipe is gradually decreasing while the strength level is gradually increasing. Correspondingly, t...

Examples

Embodiment Construction

[0029] The invention provides a X70M hot-rolled steel plate for a thin gauge gas transmission straight seam welded pipe. The thickness of the steel plate is 10-18mm; the chemical composition of the steel plate is calculated by weight percentage: C 0.05%-0.09%, Si 0.10 %~0.35%, Mn1.50%~1.80%, P≤0.020%, S≤0.015%, Nb 0.04%~0.09%, Ti 0.008%~0.0250%, Al0.015%~0.045%, Cr≤0.4%, V 0.020% ~ 0.06%, N 0.0041% ~ 0.006%, the balance is Fe and unavoidable impurities; O ≤ 0.0050% in impurities, and the total amount of other impurity elements is less than 0.05%.

[0030] A method for manufacturing X70M hot-rolled steel plates for thin-gauge gas transmission straight seam welded pipes. The production process is molten steel smelting→outside furnace refining, degassing→continuous casting→slab reheating→controlled rolling→controlled cooling→air cooling to room temperature ;details as follows:

[0031] 1) Process from molten steel smelting to continuous casting:

[0032] The raw material is pre...