An economical thick-walled high-strength toughness x70m hot-rolled steel plate and its manufacturing method

A technology for high-strength and toughness, hot-rolled steel sheets, applied in the field of low-carbon microalloyed steel production, can solve the problems of poor performance uniformity, high rolling resistance, and high straightening resistance of steel sheets, and achieves improved performance uniformity and high rolling temperature. , Improve the effect of plastic toughness

CN112981257BActive Publication Date: 2022-03-22ANGANG STEEL CO LTD
8 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2022-03-22

Smart Images

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

Abstract

The invention relates to an economical thick-walled high-strength toughness X70M hot-rolled steel plate and a manufacturing method thereof. The chemical composition of the steel plate is calculated by weight percentage: C 0.045%-0.09%, Si 0.10%-0.35%, Mn 1.50%-1.85% , P≤0.01%, S≤0.015%, Nb 0.04%~0.09%, Ti 0.008%~0.0250%, Al 0.015%~0.045%, Cr 0.25%~0.5%, Cu 0.15%~0.55%, Zr 0.02%~ 0.04%, N 0.0041% to 0.006%, and the balance is Fe and unavoidable impurities; the steel plate of the present invention is suitable for manufacturing oil and gas transmission straight seam welded pipes with a pipe diameter of 25 to 38 mm in wall thickness, and solves the problem of rolling in the steel plate production process. It has high strength, high toughness and good comprehensive performance due to the problems of high resistance to resistance, high straightening resistance and poor uniformity of steel plate properties.
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 an economical thick-walled high-strength and toughness X70M hot-rolled steel plate and a manufacturing method thereof. Background technique

[0002] Pipeline transportation is the most economical, most convenient and most important transportation method for long-distance transportation of oil and gas. Thick-gauge line pipe is mainly used in areas with special requirements and harsh environments such as large-capacity oil and gas pipelines and pipelines passing through seismic zones. With the development of oil and gas resources from inland to polar regions, from land to sea, from shallow sea to deep sea, and the development of large-scale pipeline transportation, large-diameter thick-walled line pipes will be widely used in oil and gas pipeline construction, and have good applications prospect.

[0003] In order to improve the operational safety,...

Examples

Embodiment Construction

[0032] The invention provides an economical thick-walled high-strength toughness X70M hot-rolled steel plate. The thickness of the steel plate is 25-38mm; the chemical composition of the steel plate is calculated by weight percentage: C 0.045%-0.09%, Si 0.10%-0.35% , Mn1.50%~1.85%, P≤0.01%, S≤0.015%, Nb 0.04%~0.09%, Ti 0.008%~0.0250%, Al0.015%~0.045%, Cr 0.25%~0.5%, Cu 0.15 %~0.55%, Zr 0.02%~0.04%, N0.0041%~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%.

[0033] An economical thick-walled high-strength toughness X70M hot-rolled steel plate manufacturing method, the production process is molten steel smelting → refining outside the furnace, degassing → continuous casting → slab reheating → controlled rolling → controlled cooling → air cooling to room temperature; The process is as follows:

[0034] 1) From molten steel smelting to continuous casting;

[0035] The raw material i...