Preparation method of steel for deep sea oil extraction equipment

Abstract

The invention provides a preparation method of steel for deep sea oil extraction equipment. The steel comprises the following components: 0.04-0.11 wt% of C; 1.9 to 2.5 wt% of Mn; si is 0.05 to 0.15 wt%; 0.07 to 0.16 wt% of Nb; the content of V is 0.05 to 0.097 percent by weight; 0.12 to 0.25 wt% of Mo; the content of Cr is 0.02 to 0.30 percent by weight; 0.0064 wt% to 0.0143 wt% of Cu; the content of Al is 0.011 to 0.027 percent by weight; and the balance of Fe and inevitable impurity elements. The preparation method comprises the following steps: (1) carrying out pretreatment on a steel plate, wherein the pretreatment step comprises solution treatment to obtain a solid solution state steel plate; (2) the solid solution state steel plate is subjected to subzero treatment; (3) the steel plate subjected to subzero treatment is subjected to annealing-multi-pass rolling treatment; (4) the steel plate subjected to multi-pass rolling treatment is subjected to annealing treatment; and (5) carrying out aging treatment on the annealed steel plate.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgy, and particularly relates to a preparation method of steel for deep-sea oil production equipment. Background Art

[0002] In the process of oil and gas exploitation and storage and transportation, the material requirements for equipment are more special. Especially for the steel used in deep-sea oil production equipment, it not only needs to meet the basic strength, toughness, fatigue resistance and fracture resistance, but also needs to have better sulfide stress cracking resistance and stress cracking resistance. Summary of the Invention

[0003] In order to solve the above technical problems, the present application provides a preparation method of steel for deep-sea oil production equipment, and the specific technical solution is as follows:

[0004] A preparation method of steel for deep-sea oil production equipment, the steel comprises the following components:

[0005] C 0.04 - 0.11 wt%;

[0006] Mn 1.9 - 2.5 wt%;

[0007] Si 0.05 - 0.15 wt%;

[0008] Nb 0.07 - 0.16 wt%;

[0009] V 0.05 - 0.097 wt%;

[0010] Mo 0.12 - 0.25 wt%;

[0011] Cr 0.02 - 0.30 wt%;

[0012] Cu 0.0064 - 0.0143 wt%;

[0013] Al 0.011 - 0.027 wt%;

[0014] The balance is Fe and inevitable impurity elements;

[0015] The preparation method comprises the following steps:

[0016] (1) Pretreat the steel plate, and the pretreatment step includes solution treatment to obtain a solution-treated steel plate;

[0017] (2) Perform cryogenic treatment on the solution-treated steel plate;

[0018] (3) Perform annealing-multi-pass rolling treatment on the cryogenically treated steel plate;

[0019] (4) Anneal the steel plate after multi-pass rolling treatment;

[0020] (5) Age the annealed steel sheet.

[0021] Furthermore, the total amount of Al and Cu does not exceed 10% of Mo.

[0022] Furthermore, the mass ratio of Al to Cu is 1:2.

[0023] Furthermore, for the solution treatment in step (1), the solution temperature range is 1000 - 1300 °C, the solution time range is 1 - 8 h, and the cooling method is water cooling.

[0024] Furthermore, for the cryogenic treatment in step (2), the cryogenic treatment temperature is -200 °C, the cryogenic treatment time is 2 - 4 h, and the treatment medium is liquid nitrogen.

[0025] Furthermore, in step (3), an annealing treatment is performed every time the cumulative rolling reduction reaches 20%. The annealing temperature is 150 - 250 °C, the annealing time range is 5 - 30 min, and the cooling method is air cooling; the multi-pass rolling reduction in step (3) is 70 - 95%, the strain of a single pass is less than 0.1, and the rolling reduction per pass is less than 5%.

[0026] Furthermore, for the annealing treatment in step (4), the annealing temperature range is 550 - 650 °C, the annealing time range is 3 - 30 min, and the cooling method is air cooling.

[0027] Furthermore, for the aging treatment in step (5), the aging treatment temperature range is 400 - 550 °C, the aging time range is 1 - 20 h, and the cooling method is air cooling.

[0028] The beneficial effects of the present invention are as follows:

[0029] The steel for deep-sea oil production equipment prepared by the present invention can meet the requirements of the SSC test while maintaining a tensile strength of 2300 MPa. Detailed implementation manners

[0030] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments. However, those skilled in the art should understand that the present invention can be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. Unless the context otherwise requires, throughout the specification and the appended claims, the word "comprising" shall be interpreted in an open, inclusive sense, i.e., as "including, but not limited to".

[0031] Example 1

[0032] Preparation method of steel for deep - sea oil production equipment, and the specific preparation steps are as follows:

[0033] (1) Perform solution treatment on the initial steel billet to obtain a solution - state steel plate;

[0034] Select a steel plate with a uniform structure and a thickness of 10 mm, the solution temperature is 1100 °C, the solution time is 2 h, and the cooling method is water - cooling;

[0035] (2) Perform cryogenic treatment on the steel plate prepared in step (1);

[0036] Select the cryogenic treatment temperature of - 200 °C, the cryogenic treatment time of 2 h, and the treatment medium of liquid nitrogen;

[0037] (3) Perform annealing - multi - pass rolling treatment on the cryogenically treated steel plate; perform multi - pass rolling treatment at room temperature on the cryogenically treated steel plate to obtain a steel plate with a thickness of 1 mm. The reduction per pass of cold rolling is < 5%, and the total cumulative reduction is 90%. Each time the cumulative rolling reduction reaches 20%, an annealing treatment is carried out. The annealing temperature is 200 °C, the annealing time range is 10 min, and the cooling method is air - cooling;

[0038] (4) Perform aging treatment on the prepared steel plate to obtain a nano - precipitation - strengthened ultra - high - strength and high - alloy steel; select the aging temperature of 500 °C, the aging time of 2 h, and the cooling method of air - cooling, then the steel for deep - sea oil production equipment is obtained.

[0039] The initial steel billet used above is made by a conventional continuous casting process. The initial steel billet provided in this embodiment contains the following components: C 0.1 wt%; Mn 2 wt%; Si 0.1 wt%; Nb 0.1 wt%; V 0.05 wt%; Mo 0.2 wt%; Cr 0.3 wt%; Cu 0.01 wt%; Al 0.02 wt%; the rest are Fe and inevitable impurity elements.

[0040] According to GB / T 228.1 - 2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", the strength test is carried out on the obtained steel, and the result is that the tensile strength is 2342 MPa.

[0041] According to the standard NACE TM0177 "Test method for resistance to sulfide stress cracking and stress corrosion cracking of metals in H2S environments", the sulfide stress cracking (SSC) test is carried out, and the result is "not broken, no crack".

[0042] Comparative example 1

[0043] Preparation method of steel for deep - sea oil production equipment, and the specific preparation steps are as follows:

[0044] (1) Solution treatment is carried out on the initial steel billet to obtain a solution-treated steel plate;

[0045] A steel plate with a uniform structure and a thickness of 10 mm is selected. The solution temperature is 1100 °C, the solution time is 2 h, and the cooling method is water cooling;

[0046] (2) Cryogenic treatment is carried out on the steel plate prepared in step (1);

[0047] The cryogenic treatment temperature is selected as -200 °C, the cryogenic treatment time is 2 h, and the treatment medium is liquid nitrogen;

[0048] (3) Annealing-multiple-pass rolling treatment is carried out on the cryogenically treated steel plate; The cryogenically treated steel plate is subjected to multiple-pass rolling treatment at room temperature to obtain a steel plate with a thickness of 1 mm. The reduction per pass of cold rolling is <5%, and the total cumulative reduction is 90%. Each time the cumulative rolling reduction reaches 20%, an annealing treatment is carried out. The annealing temperature is 200 °C, the annealing time range is 10 min, and the cooling method is air cooling;

[0049] (4) Aging treatment is carried out on the prepared steel plate to obtain a nano-precipitation-strengthened ultra-high-strength high-alloy steel; The aging temperature is selected as 500 °C, the aging time is 2 h, and the cooling method is air cooling, thus obtaining the steel for deep-sea oil production equipment.

[0050] The initial steel billet adopted above is made by a conventional continuous casting process. The initial steel billet provided in this embodiment contains the following components: C 0.11 wt%; Mn 2.5 wt%; Si 0.15 wt%; Nb 0.16 wt%; V 0.097 wt%; Mo 0.25 wt%; Cr 0.3 wt%; Al 0.027 wt%; the rest are Fe and inevitable impurity elements.

[0051] According to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", the strength test is carried out on the obtained steel, and the result is a tensile strength of 1946 MPa.

[0052] According to the standard NACE TM0177 "Test method for resistance to sulfide stress cracking and stress corrosion cracking of metals in H2S environments", the sulfide stress cracking (SSC) test is carried out, and the result is "not fractured, with cracks".

[0053] Comparative example 2

[0054] A preparation method of steel for deep-sea oil production equipment, and the specific preparation steps are as follows:

[0055] (1) Solution treatment is carried out on the initial steel billet to obtain a solution-treated steel plate;

[0056] Select a uniform structural steel plate with a thickness of 10 mm, a solution temperature of 1100 °C, a solution time of 2 h, and the cooling method is water cooling;

[0057] (2) Perform cryogenic treatment on the steel plate prepared in step (1);

[0058] Select a cryogenic treatment temperature of -200 °C, a cryogenic treatment time of 2 h, and the treatment medium is liquid nitrogen;

[0059] (3) Perform annealing - multi - pass rolling treatment on the cryogenically treated steel plate; perform multi - pass rolling treatment at room temperature on the cryogenically treated steel plate to obtain a steel plate with a thickness of 1 mm. The reduction per pass of cold rolling is <5%, and the total cumulative reduction is 90%. Whenever the cumulative rolling reduction reaches 20%, an annealing treatment is carried out. The annealing temperature is 200 °C, the annealing time range is 10 min, and the cooling method is air cooling;

[0060] (4) Perform aging treatment on the prepared steel plate to obtain a nano - precipitation - strengthened ultra - high - strength and high - alloy steel; select an aging temperature of 500 °C, an aging time of 2 h, and the cooling method is air cooling, then the steel for deep - sea oil production equipment is obtained.

[0061] The initial steel billet used above is made by a conventional continuous casting process. The initial steel billet provided in this example contains the following components: C 0.1 wt%; Mn 2 wt%; Si 0.1 wt%; Nb 0.1 wt%; V 0.05 wt%; Mo 0.2 wt%; Cr 0.3 wt%; Cu 0.01 wt%; the rest are Fe and unavoidable impurity elements.

[0062] According to GB / T 228.1 - 2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", perform a strength test on the obtained steel, and the result is a tensile strength of 2418 MPa.

[0063] Carry out a sulfide stress cracking (SSC) test in accordance with the standard NACETM0177 "Test method for resistance to sulfide stress cracking and stress - corrosion cracking of metals in H2S environments", and the result is "not broken, with cracks".

[0064] Combined with Example 1, Comparative Example 1 and Comparative Example 2, it can be seen that only when adding Cu 0.0064 - 0.0143 wt% and Al 0.011 - 0.027 wt% simultaneously in the component system of C 0.04 - 0.11 wt%; Mn 1.9 - 2.5 wt%; Si 0.05 - 0.15 wt%; Nb 0.07 - 0.16 wt%; V 0.05 - 0.097 wt%; Mo 0.12 - 0.25 wt%; Cr 0.02 - 0.30 wt% can meet the requirements of the SSC test while maintaining the tensile strength reaching 2300 MPa.

[0065] Example 2

[0066] The preparation method of the steel for deep - sea oil production equipment is as follows:

[0067] (1) Solution treatment is carried out on the initial steel billet to obtain a solution - state steel plate.

[0068] Select a steel plate with a thickness of 10 mm and a uniform structure. The solution temperature is 1100 °C, the solution time is 2 h, and the cooling method is water - cooling.

[0069] (2) Cryogenic treatment is carried out on the steel plate prepared in step (1).

[0070] Select a cryogenic treatment temperature of - 200 °C, a cryogenic treatment time of 2 h, and the treatment medium is liquid nitrogen.

[0071] (3) Annealing - multi - pass rolling treatment is carried out on the cryogenically treated steel plate; the cryogenically treated steel plate is subjected to multi - pass rolling treatment at room temperature to obtain a steel plate with a thickness of 1 mm. The reduction per pass of cold rolling is < 5%, and the total cumulative reduction is 90%. Each time the cumulative rolling reduction reaches 20%, an annealing treatment is carried out. The annealing temperature is 200 °C, the annealing time range is 10 min, and the cooling method is air - cooling.

[0072] (4) Aging treatment is carried out on the prepared steel plate to obtain a nano - precipitation - strengthened ultra - high - strength and high - alloy steel; select an aging temperature of 500 °C, an aging time of 2 h, and the cooling method is air - cooling, then the steel for deep - sea oil production equipment is obtained.

[0073] The above - mentioned initial steel billet is made by a conventional continuous casting process. The initial steel billet provided in this example contains the following components: C 0.1 wt%; Mn 2 wt%; Si 0.1 wt%; Nb 0.1 wt%; V 0.05 wt%; Mo 0.2 wt%; Cr 0.3 wt%; Cu 0.005 wt%; Al 0.015 wt%; the rest are Fe and inevitable impurity elements.

[0074] The obtained steel was subjected to a strength test according to GB / T 228.1-2021 "Tensile tests on metallic materials - Part 1: Room temperature test methods", and the result showed a tensile strength of 2463 MPa.

[0075] The sulfide stress cracking (SSC) test was carried out in accordance with the standard NACETM0177 "Test method for resistance of metals to sulfide stress cracking, stress cracking and stress corrosion cracking in H2S environment", and the result was "no breakage and no cracks".

[0076] Example 3

[0077] The preparation method of steel for deep-sea oil production equipment includes the following specific preparation steps:

[0078] (1) performing a solution treatment on the initial steel billet to obtain a solid solution steel plate;

[0079] A uniform structural steel plate with a thickness of 10 mm was selected, the solution temperature was 1100 ° C, the solution time was 2 h, and the cooling method was water cooling;

[0080] (2) performing cryogenic treatment on the steel plate prepared in step (1);

[0081] The cryogenic treatment temperature is -200℃, the cryogenic treatment time is 2h, and the treatment medium is liquid nitrogen;

[0082] (3) Annealing and multi-pass rolling treatment are performed on the steel plate after cryogenic treatment; the steel plate after cryogenic treatment is subjected to multi-pass rolling treatment at room temperature to obtain a steel plate with a thickness of 1 mm, the reduction amount of each cold rolling pass is less than 5%, and the total cumulative reduction amount is 90%. Annealing treatment is performed every time the cumulative rolling amount reaches 20%, the annealing temperature is 200°C, the annealing time range is 10 minutes, and the cooling method is air cooling;

[0083] (4) The prepared steel plate is subjected to aging treatment to obtain nano-precipitation strengthened ultra-high strength high alloy steel; the aging temperature is selected to be 500°C, the aging time is selected to be 2 hours, and the cooling method is air cooling, thus obtaining steel for deep-sea oil production equipment.

[0084] The initial steel billet used above is produced by a conventional continuous casting process. The initial steel billet provided in this embodiment contains the following components: C 0.1wt%; Mn 2wt%; Si 0.1wt%; Nb 0.1wt%; V 0.05wt%; Mo 0.2wt%; Cr 0.3wt%; Cu 0.005wt%; Al 0.01wt%; the remainder is Fe and unavoidable impurity elements.

[0085] The obtained steel was subjected to a strength test according to GB / T 228.1-2021 "Tensile testing of metallic materials - Part 1: Method of test at room temperature", and the result was a tensile strength of 2511 MPa.

[0086] The sulfide stress cracking (SSC) test was carried out in accordance with the standard NACE TM0177 "Test method for resistance to sulfide stress cracking and stress corrosion cracking of metals in H2S environments", and the result was "not broken, no crack".

[0087] Combining Example 1, Example 2 and Example 3, it can be seen that in the entire steel component system, the total addition amount of Cu and Al should also be restricted so that it does not exceed 10% of the addition amount of Mo, which is beneficial to further improving the tensile strength of the steel; at the same time, when the mass ratio of Cu and Al is controlled to be 1:2, there is a tendency to further improve the tensile strength of the steel.

[0088] The above examples are only used to illustrate the technical solutions of the present invention and are not intended to limit it.

Claims

1. Preparation method of steel for deep-sea oil production equipment, characterized in that, The steel includes the following components: C 0.04 - 0.11 wt%; Mn 1.9 - 2.5 wt%; Si 0.05 - 0.15 wt%; Nb 0.07 - 0.16 wt%; V 0.05 - 0.097 wt%; Mo 0.12 - 0.25 wt%; Cr 0.02 - 0.30 wt%; Cu 0.0064 - 0.0143 wt%; Al 0.011 - 0.027 wt%; The balance is Fe and inevitable impurity elements; The preparation method includes the following steps: (1) Pretreat the steel plate, and the pretreatment step includes solution treatment to obtain a solution-treated steel plate; (2) Perform cryogenic treatment on the solution-treated steel plate; (3) Perform annealing - multi-pass rolling treatment on the cryogenically treated steel plate; (4) Anneal the steel plate after multi-pass rolling treatment; (5) Perform aging treatment on the annealed steel plate.

2. The preparation method of the steel for deep-sea oil production equipment according to claim 1, characterized in that, The total amount of Al and Cu does not exceed 10% of Mo.

3. The preparation method of the steel for deep-sea oil production equipment according to claim 1 or 2, characterized in that, The mass ratio of Al to Cu is 1:

2.

4. The production process of the preparation method of the steel for deep-sea oil production equipment according to claim 1, characterized in that, For the solution treatment in step (1), the solution temperature range is 1000 - 1300 °C, the solution time range is 1 - 8 h, and the cooling method is water cooling.

5. The production process of the preparation method of the steel for deep-sea oil production equipment according to claim 1, characterized in that, For the cryogenic treatment in step (2), the cryogenic treatment temperature is -200 °C, the cryogenic treatment time is 2 - 4 h, and the treatment medium is liquid nitrogen.

6. The production process of the preparation method of the steel for deep-sea oil production equipment according to claim 1, characterized in that, In step (3), annealing treatment is performed once whenever the cumulative rolling reduction reaches 20%. The annealing temperature is 150 - 250 °C, the annealing time range is 5 - 30 min, and the cooling method is air cooling; the multi-pass rolling reduction in step (3) is 70 - 95%, the strain per single pass is less than 0.1, and the rolling reduction per pass is less than 5%.

7. The production process of the preparation method of the steel for deep-sea oil production equipment according to claim 1, characterized in that, For the annealing treatment in step (4), the annealing temperature range is 550 - 650 °C, the annealing time range is 3 - 30 min, and the cooling method is air cooling.

8. The production process of the preparation method of the steel for deep-sea oil production equipment according to claim 1, characterized in that, For the aging treatment in step (5), the aging temperature range is 400 - 550 °C, the aging time range is 1 - 20 h, and the cooling method is air cooling.