Acid-resistant pipeline steel plate and rolling process thereof

Abstract

The invention discloses an acid-resistant pipeline steel plate, which relates to the technical field of metallurgy and comprises the following chemical components in percentage by mass: 0.03 to 0.060 percent of C, 0.1 to 0.3 percent of Si, 0.6 to 1.3 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.0010 percent of S, 0.10 to 0.50 percent of Ni, 0.10 to 0.50 percent of Cu, 0.02 to 0.07 percent of Nb, 0.08 to 0.15 percent of Mo, 0.01 to 0.02 percent of Ti, 0.001 to 0.003 percent of Ca, 0.01 to 0.04 percent of Al and the balance of Fe and inevitable impurities. The low-carbon, low-phosphorus and low-sulfur component design is adopted, the strength of a product is improved by using chromium, nickel, molybdenum and copper, a diffusion channel of a poisoning agent H2S is prevented by improving the core defect of the structure, and the acid resistance and corrosion resistance are improved.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to an acid-resistant pipeline steel plate and a rolling process thereof. Background Art

[0002] With the rapid development of the oil and gas industry, the transportation efficiency has been further improved, the crude oil transportation volume has been increasing, and there are more and more acid-resistant and corrosion-resistant pipeline steel products. Therefore, the development and design of acid-resistant and corrosion-resistant steel has received great attention from enterprises. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the disadvantages of the prior art and provide an acid-resistant pipeline steel plate and a rolling process thereof.

[0004] In order to solve the above technical problems, the technical solution of the present invention is as follows: An acid-resistant pipeline steel plate, whose chemical composition and mass percentage are as follows: C: 0.03-0.060%, Si: 0.1-0.3%, Mn: 0.6-1.3%, P≤0.015%, S≤0.0010%, Ni: 0.10-0.50%, Cu: 0.10-0.50%, Nb: 0.02-0.07%, Mo: 0.08-0.15%, Ti: 0.01-0.02%, Ca: 0.001-0.003%, Al: 0.01-0.04%, and the balance is Fe and unavoidable impurities.

[0005] As a preferred embodiment of the acid-resistant pipeline steel plate described in the present invention, its chemical composition and mass percentage are as follows: C: 0.03-0.050%, Si: 0.1-0.2%, Mn: 0.6-1.1%, P≤0.015%, S≤0.0010%, Ni: 0.10-0.30%, Cu: 0.10-0.30%, Nb: 0.02-0.05%, Mo: 0.08-0.13%, Ti: 0.01-0.02%, Ca: 0.001-0.003%, Al: 0.01-0.04%, and the balance is Fe and unavoidable impurities.

[0006] As a preferred embodiment of the acid-resistant pipeline steel plate described in the present invention, its chemical composition and mass percentage are as follows: C: 0.04-0.060%, Si: 0.2-0.3%, Mn: 0.8-1.3%, P≤0.015%, S≤0.0010%, Ni: 0.20-0.50%, Cu: 0.30-0.50%, Nb: 0.04-0.07%, Mo: 0.10-0.15%, Ti: 0.01-0.02%, Ca: 0.001-0.003%, Al: 0.01-0.04%, and the balance is Fe and unavoidable impurities.

[0007] The present invention also provides a rolling process for an acid-resistant pipeline steel plate, comprising: The blank is sent into a walking beam heating furnace for heating, and the austenitizing temperature is controlled to be 1150-1210°C; The heated billet is subjected to warm rough rolling, and the final rough rolling reduction rate is controlled to be no less than 20%; When the thickness of the warm billet is 4-5 times the thickness of the finished product, the finishing rolling is carried out, and the starting temperature of the finishing rolling is controlled to be 750-900℃, the final rolling temperature is 800-900℃, and the water inlet temperature is 750-850℃; The rolled steel plates are cooled on a cooling bed and then warm straightened. After warm straightening, they are sheared, marked, inspected for flaws, and put into storage.

[0008] As a preferred solution of the rolling process of the acid-resistant pipeline steel plate described in the present invention, the heating time of the billet in the walking-beam heating furnace is 10 to 13 min / cm calculated based on the billet thickness, and the soaking time is greater than or equal to 40 min.

[0009] As a preferred solution of the rolling process of the acid-resistant pipeline steel plate of the present invention, the finish rolling is performed using odd passes.

[0010] As a preferred solution of the rolling process of the acid-resistant pipeline steel plate described in the present invention, in the finishing rolling process, the cooling roller speed is controlled to be 0.8-1.5 m / s, and the temperature after cooling is controlled to be 350-490°C.

[0011] The beneficial effects of the present invention are: (1) The present invention adopts a low-carbon, low-phosphorus and low-sulfur component design, and uses chromium, nickel, molybdenum and copper to improve the strength of the product. By improving the core defects of the tissue, the poisoning agent H 2 The diffusion channel of S improves the acid and corrosion resistance.

[0012] (2) The present invention refines the grain size of the structure, improves the passage of corrosive gas in the intergranular gap, and enhances the corrosion resistance through the application of low-temperature heating and low-temperature rolling technology.

[0013] (3) The present invention adopts the post-rolling rapid cooling and low reddening technology to improve the adverse effects of the banded structure, obtain the microstructure of low-temperature ferrite and bainite, and achieve the performance requirements of pipeline steel for acid and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0015] Figure 1 The near-surface metallographic structure diagram of the acid-resistant pipeline steel plate prepared in Example 1; Figure 2 The metallographic structure diagram of the acid-resistant pipeline steel plate at 1 / 4 of the thickness prepared in Example 1; Figure 3 This is the metallographic structure diagram of the thick core of the acid-resistant pipeline steel plate prepared in Example 1. DETAILED DESCRIPTION

[0016] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific implementation modes and in combination with the accompanying drawings. Example

[0017] The present embodiment provides an acid-resistant pipeline steel plate, whose chemical composition and mass percentage are as follows: C: 0.030%, Si: 0.15%, Mn: 0.77%, P: 0.011%, S: 0.0008%, Ni: 0.17%, Cu: 0.18%, Nb: 0.03%, Mo: 0.09%, Ti: 0.016%, Ca: 0.002%, Al: 0.03%, and the balance is Fe and unavoidable impurities.

[0018] This embodiment also provides a rolling process for an acid-resistant pipeline steel plate, which specifically includes the following steps: Step S101: After the surface inspection of the blank, the blank is sent into a walking beam heating furnace for heating, and the austenitizing temperature is controlled to be 1150-1210°C, the heating time is calculated as 12 min / cm based on the blank thickness, and the soaking time is not less than 40 min.

[0019] Step S102: performing warm rough rolling on the heated billet, and controlling the final rough rolling reduction ratio to be no less than 20%.

[0020] Specifically, the rolling model is adjusted to ensure that the final rough rolling reduction is not less than 20%. The grain size of the microstructure is refined through warm rolling to improve the strength and toughness of the product.

[0021] Step S103: When the thickness of the warm billet is 4.1 times the thickness of the finished product, finish rolling is performed, and the start rolling temperature of the finish rolling is controlled to be 750-900°C, the final rolling temperature is 800-900°C, and the water inlet temperature is 750-850°C.

[0022] Specifically, the finishing rolling process adopts odd-pass rolling to reduce the time from final rolling to water entry and ensure the water entry temperature of the steel plate. The cooling roller speed is controlled at 0.8-1.5m / s, and the red-return temperature after cooling is controlled at 350-490℃.

[0023] At the same time, a new cooling stage is adopted to reduce the time from pre-correction to water cooling, thereby refining the grains and effectively improving the adverse effects of banded structure.

[0024] Step S104: After the rolled steel plate is cooled on a cooling bed, it is subjected to warm straightening, and after the warm straightening, it is sheared, marked, flaw-detected, and stored. Example

[0025] The present embodiment provides an acid-resistant pipeline steel plate, whose chemical composition and mass percentage are as follows: C: 0.043%, Si: 0.26%, Mn: 1.2%, P: 0.011%, S: 0.0009%, Ni: 0.43%, Cu: 0.35%, Nb: 0.060%, Mo: 0.11%, Ti: 0.011%, Ca: 0.002%, Al: 0.03%, and the balance is Fe and unavoidable impurities.

[0026] This embodiment also provides a rolling process for acid-resistant pipeline steel plates, and the steps of the process are the same as the steps of the rolling process for acid-resistant pipeline steel plates in Example 1. Example

[0027] The present embodiment provides an acid-resistant pipeline steel plate, whose chemical composition and mass percentage are as follows: C: 0.020%, Si: 0.23%, Mn: 0.86%, P: 0.009%, S: 0.0006%, Ni: 0.16%, Cu: 0.17%, Nb: 0.031%, Mo: 0.009%, Ti: 0.015%, Ca: 0.002%, Al: 0.033%, and the balance is Fe and unavoidable impurities.

[0028] This embodiment also provides a rolling process for acid-resistant pipeline steel plates, and the steps of the process are the same as the steps of the rolling process for acid-resistant pipeline steel plates in Example 1.

[0029] The HTC performance tests of Examples 1 to 3 are shown in Table 1.

[0030]

[0031] Table 1 Select the steel plate obtained in Example 1 to obtain Figure 1 , 2The metallographic structure of 3 is uniform and fine, the structure is mainly ferrite and contains a small amount of bainite. The grain size rating is 10. The acid resistance of the steel plate meets the relevant requirements of API 5L, meets the customer's usage needs, and meets the design requirements.

[0032] In addition to the above embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. An acid-resistant pipeline steel plate, characterized in that: Its chemical composition and mass percentage are as follows: C: 0.03~0.060%, Si: 0.1~0.3%, Mn: 0.6~1.3%, P≤0.015%, S≤0.0010%, Ni: 0.10~0.50%, Cu: 0.10~0.50%, Nb: 0.02~0.07%, Mo: 0.08~0.15%, Ti: 0.01~0.02%, Ca: 0.001~0.003%, Al: 0.01~0.04%, and the balance is Fe and unavoidable impurities.

2. The acid-resistant pipeline steel plate according to claim 1, characterized in that: Its chemical composition and mass percentage are as follows: C: 0.03-0.050%, Si: 0.1-0.2%, Mn: 0.6-1.1%, P≤0.015%, S≤0.0010%, Ni: 0.10-0.30%, Cu: 0.10-0.30%, Nb: 0.02-0.05%, Mo: 0.08-0.13%, Ti: 0.01-0.02%, Ca: 0.001-0.003%, Al: 0.01-0.04%, and the balance is Fe and unavoidable impurities.

3. The acid-resistant pipeline steel plate according to claim 1, characterized in that: Its chemical composition and mass percentage are as follows: C: 0.04-0.060%, Si: 0.2-0.3%, Mn: 0.8-1.3%, P≤0.015%, S≤0.0010%, Ni: 0.20-0.50%, Cu: 0.30-0.50%, Nb: 0.04-0.07%, Mo: 0.10-0.15%, Ti: 0.01-0.02%, Ca: 0.001-0.003%, Al: 0.01-0.04%, and the balance is Fe and unavoidable impurities.

4. A rolling process for the acid-resistant pipeline steel plate according to any one of claims 1 to 3, characterized in that: include: The blank is sent into a walking beam heating furnace for heating, and the austenitizing temperature is controlled to be 1150-1210°C; The heated billet is subjected to warm rough rolling, and the final rough rolling reduction rate is controlled to be no less than 20%; When the thickness of the warm billet is 4-5 times the thickness of the finished product, the finishing rolling is carried out, and the starting temperature of the finishing rolling is controlled to be 750-900℃, the final rolling temperature is 800-900℃, and the water inlet temperature is 750-850℃; The rolled steel plates are cooled on a cooling bed and then warm straightened. After warm straightening, they are sheared, marked, inspected for flaws, and put into storage.

5. The rolling process of the acid-resistant pipeline steel plate according to claim 4, characterized in that: The heating time of the blank in the walking beam heating furnace is 10 to 13 min / cm calculated based on the thickness of the blank, and the soaking time is greater than or equal to 40 min.

6. The rolling process of the acid-resistant pipeline steel plate according to claim 4, characterized in that: The finish rolling is performed by odd passes.

7. The rolling process of the acid-resistant pipeline steel plate according to claim 4, characterized in that: In the finishing rolling process, the cooling roller speed is controlled to be 0.8-1.5 m / s, and the temperature after cooling is controlled to be 350-490°C.

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