A high-strength and highly corrosion-resistant steel wire for a ten-thousand-meter oil well detection cable and its preparation method

Abstract

The present invention discloses a high-strength and highly corrosion-resistant steel wire for ten-thousand-meter oil well detection cables and a preparation method thereof. The steel wire comprises the following elements by mass ratio: C: 0.87-0.96 wt.%, Si: 0.5-0.7 wt.%, Mn: 0.5-0.7 wt.%, P: ≤0.01 wt.%, S: ≤0.01 wt.%, Cr: 0.3-0.6 wt.%, Ce: 0.05-0.15 wt.%, and Fe: the balance. The manufacturing method is as follows: The wire rod is cold drawn to obtain cold-drawn steel wire, and then is subjected to austenitizing heat treatment and isothermal quenching treatment to obtain a sorbite structure. Then, a pure zinc coating is hot-dip galvanized, and cold drawing deformation is carried out; a Zn-Al-Mg alloy coating is hot-dip galvanized on the surface of the galvanized steel wire, and then it is cold drawn to obtain. The present invention improves the tensile strength, corrosion resistance and wear resistance of the steel wire.

Description

Technical Field

[0001] The present invention relates to a steel wire for cables and a preparation method thereof, and particularly to a high-strength and highly corrosion-resistant steel wire for ten-thousand-meter oil well detection cables and a preparation method thereof. Background Art

[0002] The load-bearing detection cable, also known as the oil well logging cable, is mainly used for the detection of oil and gas wells, and can also be used in aspects such as ocean surveys, coalfield geological explorations, and geothermal logging. During the process of exploring oil wells, the cable needs to bear its own weight and the weight of the hanging hammer, and the detection depth of the oil well is gradually increasing, which puts forward higher requirements for the tensile strength of the armored steel wire on the outer side of the cable. At the same time, there is a complex corrosion environment in the oil well, and the well temperature will increase with the increase of the detection depth, which will shorten the service life of the cable. During use, the coating on the surface of the steel wire is easily peeled off under the action of friction, thus losing the protection effect on the steel wire matrix.

[0003] To solve the above problems, it is necessary to develop armored steel wires for load-bearing detection cables with high strength, high temperature resistance, high corrosion resistance and high wear resistance, so as to extend the service life of the cable. At present, the carbon content of the original coil of the armored steel wire for load-bearing detection cables is relatively low, and the finished steel wire can meet the oil well detection at a certain depth (<7000m). The traditional armored steel wire for load-bearing detection cables uses a hot-dip pure zinc coating to protect the steel wire matrix, with poor corrosion resistance, and the coating is prone to cracking during the cold drawing deformation process, affecting its use performance. Summary of the Invention

[0004] Object of the Invention: The object of the present invention is to provide a high-strength and highly corrosion-resistant steel wire for ten-thousand-meter oil well detection cables that can avoid cracking of the coating during the drawing process;

[0005] The second object of the present invention is to provide a preparation method for the above-mentioned high-strength and highly corrosion-resistant steel wire for ten-thousand-meter oil well detection cables.

[0006] Technical Solution: The high-strength and highly corrosion-resistant steel wire for ten-thousand-meter oil well detection cables described in the present invention includes the following elements according to the mass ratio: C: 0.87 - 0.96 wt.%, Si: 0.5 - 0.7 wt.%, Mn: 0.5 - 0.7 wt.%, P: ≤0.01 wt.%, S: ≤0.01 wt.%, Cr: 0.3 - 0.6 wt.%, Ce: 0.05 - 0.15 wt.%, Fe: the balance.

[0007] The functions of each element are as follows: 1) C: improves the tensile strength of the steel wire; 2) Si: a) exists in the steel wire matrix in the form of solid solution, playing a role in solid solution strengthening, b) enhances the passivation effect of the steel wire matrix, improves the intergranular corrosion resistance of the steel wire, c) improves the anti-tempering softening ability of the steel wire matrix, so that it can be used in oil wells at higher temperatures and extends the service life of the steel wire; 3) Mn: improves the hardenability of the steel wire matrix; 4) Cr: improves the corrosion resistance and hardenability of the steel wire matrix; 5) Ce: as a micro-alloying element, plays a role in modifying inclusions, thereby improving the drawability of the steel wire matrix.

[0008] The present invention improves the tensile strength and corrosion resistance of the steel wire matrix by increasing the contents of elements C, Si, Mn, Cr, and Ce in the original wire rod.

[0009] The preparation method of the high-strength and highly corrosion-resistant steel wire for the ten-thousand-meter-level oil well detection cable is as follows:

[0010] (1) Cold-draw the wire rod to obtain cold-drawn steel wire;

[0011] (2) Austenitize and quench the cold-drawn steel wire to obtain steel wire with a sorbite structure;

[0012] (3) Hot-dip the steel wire obtained in step (2) with a pure zinc coating, and then cold-draw it to obtain galvanized steel wire;

[0013] (4) Hot-dip a Zn-Al-Mg alloy coating on the surface of the cold-drawn galvanized steel wire, and then cold-draw it to obtain the high-strength and highly corrosion-resistant steel wire for the ten-thousand-meter-level oil well detection cable.

[0014] Among them, in step (3), the temperature of the hot-dip pure zinc coating is 440°C to 460°C, and the time is 10 to 30 s; the diameter of the galvanized steel wire after cold drawing is 2.6 to 3.2 mm. A pure zinc coating with good tissue properties can be obtained by hot-dip coating within this temperature and time range. When the diameter of the galvanized steel wire after cold drawing is within this range, it is beneficial for subsequent hot-dip coating.

[0015] Among them, in step (4), the temperature of the hot-dip Zn-Al-Mg alloy coating is 420°C to 450°C, and the time is 10 to 20 s; the mass fraction of Al in the Zn-Al-Mg alloy coating is 3 to 10 wt.%, the mass fraction of Mg is 1 to 6 wt.%, the mass fraction of Ce is 0.01 to 0.5 wt.%, and the rest is Zn. The present invention hot-dips a Zn-Al-Mg alloy coating on the surface of the galvanized steel wire, improving the corrosion resistance of the steel wire. A coating with good tissue properties can be obtained by hot-dip coating within this temperature and time range.

[0016] Among them, in step (4), after the cold drawing, the steel wire is heat-treated for stabilization at 265°C to 275°C for 30 to 60 minutes; the mobile dislocations in the steel wire matrix move, thereby improving the stability of the steel wire matrix. Heat treatment for stabilization within this temperature range can meet the service requirements in 260°C oil wells.

[0017] Among them, in step (1), the diameter of the wire rod is 5 to 6 mm.

[0018] Among them, in step (2), the austenitizing heat treatment temperature is 800°C to 850°C, and the time is 5 to 10 minutes.

[0019] Among them, before step (3), the steel wire is subjected to fluxing treatment. The composition of the fluxing agent is, by mass ratio, ZnCl2: 10 to 20 wt.%, NH4Cl: 5 to 15 wt.%, SnCl2: 5 to 15 wt.%, KCl: 2 to 8 wt.%, CeCl3: 0.1 to 1 wt.%, CH3OH: 5 to 10 wt.%, and the rest is water; the fluxing temperature is 80°C to 90°C, and the fluxing time is 1 to 3 minutes.

[0020] Beneficial effects: Compared with the prior art, the present invention has achieved the following remarkable effects: 1. While the C content is increased compared with the conventional oil well detection steel wire, the present invention adds a drawing process between the galvanized layer and the Zn-Al-Mg alloy coating, and a steel wire with excellent tissue properties can be obtained, improving the corrosion resistance and wear resistance of the steel wire for oil well detection cables. During use, the coating is not likely to fall off. The tensile strength of the steel wire of the present invention is above 2400 MPa, meeting the strength requirements of the steel wire for ten-thousand-meter oil well detection cables; 2. The steel wire of the present invention can be used in oil wells below 260°C, improving the high-temperature resistance of the steel wire; 3. The present invention extends the service life of the steel wire; 4. The operation of the present invention is simple. Detailed implementation manners

[0021] The present invention will be further described in detail below.

[0022] Example 1

[0023] A preparation method of a high-strength and highly corrosion-resistant steel wire for ten-thousand-meter oil well detection cables mainly includes the following steps:

[0024] (1) The Φ5 mm high-carbon wire rod is cold-drawn and deformed to obtain a Φ4.1 mm cold-drawn steel wire. The composition design of the steel wire is: C:Si:Mn:P:S:Cr:Ce:Fe = 0.87 wt.%:0.5 wt.%:0.5 wt.%:0.005 wt.%:0.005 wt.%:0.3 wt.%:0.05 wt.%:the balance;

[0025] (2) The cold drawn steel wire is subjected to austenitizing heat treatment and quenching treatment, the austenitizing heat treatment temperature is 800°C, the time is 5 minutes, and the sorbite structure is obtained;

[0026] (3) performing surface treatment before plating, including alkali washing, water washing, pickling, water washing steps, and then drying;

[0027] (4) flux treatment, wherein the flux composition is in the following mass ratio: ZnCl2: NH4Cl: SnCl2: KCl: CeCl3: CH3OH: H2O = 10 wt.%: 5 wt.%: 5 wt.%: 2 wt.%: 0.1 wt.%: 5 wt.%: balance, the flux temperature is 80°C, and the flux time is 1 min;

[0028] (5) After the plating and drying treatment, the pure zinc coating was hot-dip coated at 440°C for 10 seconds, and then the galvanized steel wire was cold-drawn to Φ2.6mm;

[0029] (6) hot-dip coating of a Zn-Al-Mg alloy coating on the surface of a cold-drawn galvanized steel wire at a coating temperature of 420° C. for 10 seconds, wherein the coating composition is Al:Mg:Ce:Zn=3wt.%:1wt.%:0.01wt.%:balance, and then the coated steel wire is cold-drawn to a diameter of 1.26 mm;

[0030] (7) The steel wire is kept at 265°C for 30 minutes and then air-cooled to room temperature.

[0031] After testing, the obtained coated steel wire for oil well detection cable has a tensile strength of 2400MPa and a neutral salt spray corrosion rate of 0.1682g·m -2 ·h -1 The coating structure is uniform and meets the detection requirements of 10,000m oil wells.

[0032] Example 2

[0033] A method for preparing high-strength, high-corrosion-resistant steel wire for 10,000-meter-long oil well detection cables mainly comprises the following steps:

[0034] (1) A Φ5.5 mm high carbon wire rod is cold drawn to obtain a Φ4.1 mm cold drawn steel wire. The composition of the steel wire is designed as follows: C:Si:Mn:P:S:Cr:Ce:Fe=0.9wt.%:0.55wt.%:0.55wt.%:0.005wt.%:0.005wt.%:0.4wt.%:0.05wt.%:balance;

[0035] (2) The cold drawn steel wire is subjected to austenitizing heat treatment and quenching treatment. The austenitizing heat treatment temperature is 810°C and the time is 6 minutes to obtain a sorbite structure.

[0036] (3) Conduct surface treatment before fluxing, including steps such as alkali washing, water washing, acid pickling, water washing, etc., and then drying;

[0037] (4) Fluxing treatment, the composition of the flux is in a mass ratio of ZnCl2:NH4Cl:SnCl2:KCl:CeCl3:CH3OH:H2O = 13 wt.%, 8 wt.%, 8 wt.%, 4 wt.%, 0.4 wt.%, 6 wt.%, and the balance. The fluxing temperature is 83 °C and the fluxing time is 1.5 min.

[0038] (5) After fluxing and drying treatment, hot dip galvanize with a pure zinc coating at 445 °C for 15 s, and then cold draw the galvanized steel wire to Φ2.8 mm;

[0039] (6) Hot dip galvanize a Zn-Al-Mg alloy coating on the surface of the cold-drawn galvanized steel wire, the dipping temperature is 430 °C, the dipping time is 15 s, and the coating composition is in a mass ratio of Al:Mg:Ce:Zn = 5 wt.%, 3 wt.%, 0.1 wt.%, and the balance. Then cold draw the coated steel wire to Φ1.26 mm;

[0040] (7) After the steel wire is kept at 270 °C for 40 min, it is air-cooled to room temperature.

[0041] After testing, a coated steel wire for oil well detection cable with a tensile strength of 2410 MPa is obtained, and the neutral salt spray corrosion rate is 0.1723 g·m -2 ·h -1 , the coating structure is uniform, meeting the detection requirements of 10000 m oil wells.

[0042] Example 3

[0043] A preparation method of high-strength and high-corrosion-resistant steel wire for ten-thousand-meter oil well detection cable mainly includes the following steps:

[0044] (1) Cold draw and deform the Φ5.5 mm high-carbon wire rod to obtain a cold-drawn steel wire of Φ4.1 mm. The composition design of the steel wire is: C:Si:Mn:P:S:Cr:Ce:Fe = 0.93 wt.%, 0.6 wt.%, 0.6 wt.%, 0.01 wt.%, 0.01 wt.%, 0.5 wt.%, 0.1 wt.%, and the balance;

[0045] (2) Conduct austenitizing heat treatment and quenching treatment on the cold-drawn steel wire. The austenitizing heat treatment temperature is 830 °C and the time is 8 min to obtain a sorbite structure;

[0046] (3) Conduct surface treatment before fluxing, including steps such as alkali washing, water washing, acid pickling, water washing, etc., and then drying;

[0047] (4) Fluxing treatment, the composition of the flux is in a mass ratio of ZnCl2:NH4Cl:SnCl2:KCl:CeCl3:CH3OH:H2O = 16 wt.%:11 wt.%:11 wt.%:6 wt.%:0.7 wt.%:8 wt.%:the balance, the fluxing temperature is 86 °C, and the fluxing time is 2 min;

[0048] (5) After fluxing and drying treatments, a pure zinc coating is hot-dip coated at 450 °C for 20 s, and then the galvanized steel wire is cold drawn to Φ3.0 mm;

[0049] (6) A Zn-Al-Mg alloy coating is hot-dip coated on the surface of the cold-drawn galvanized steel wire, the coating temperature is 440 °C, the coating time is 15 s, and the coating composition is in a mass ratio of Al:Mg:Ce:Zn = 8 wt.%:5 wt.%:0.3 wt.%:the balance, and then the coated steel wire is cold drawn to Φ1.26 mm;

[0050] (7) After the steel wire is kept at 270 °C for 50 min, it is air-cooled to room temperature.

[0051] After testing, a coated steel wire for oil well exploration cables with a tensile strength of 2425 MPa is obtained, and the neutral salt spray corrosion rate is 0.1658 g·m -2 ·h -1 , the coating structure is uniform and meets the detection requirements of 10,000 m oil wells.

[0052] Example 4

[0053] A preparation method of high-strength and high-corrosion-resistant steel wire for ten-thousand-meter oil well exploration cables mainly includes the following steps:

[0054] (1) The Φ6 mm high-carbon wire rod is cold drawn to obtain a cold-drawn steel wire of Φ4.1 mm. The composition design of the steel wire is: C:Si:Mn:P:S:Cr:Ce:Fe = 0.96 wt.%:0.7 wt.%:0.7 wt.%:0.01 wt.%:0.01 wt.%:0.6 wt.%:0.15 wt.%:the balance;

[0055] (2) The cold-drawn steel wire is subjected to austenitizing heat treatment and quenching treatment. The austenitizing heat treatment temperature is 850 °C and the time is 10 min to obtain a sorbite structure;

[0056] (3) Surface treatment before fluxing is carried out, including steps such as alkali washing, water washing, acid washing, water washing, etc., and then drying;

[0057] (4) Fluxing treatment, the flux composition is in a mass ratio of ZnCl2:NH4Cl:SnCl2:KCl:CeCl3:CH3OH:H2O = 20 wt.%:15 wt.%:15 wt.%:8 wt.%:1 wt.%:10 wt.%: balance, the fluxing temperature is 90 °C, and the fluxing time is 3 min;

[0058] (5) After fluxing and drying treatments, a pure zinc coating is hot-dip coated at 460 °C for 30 s, and then the galvanized steel wire is cold-drawn to Φ3.2 mm;

[0059] (6) A Zn-Al-Mg alloy coating is hot-dip coated on the surface of the cold-drawn galvanized steel wire at 450 °C for 20 s, and the coating composition is in a mass ratio of Al:Mg:Ce:Zn = 10 wt.%:6 wt.%:0.5 wt.%: balance, and then the coated steel wire is cold-drawn to Φ1.26 mm;

[0060] (7) After the steel wire is held at 275 °C for 60 min, it is air-cooled to room temperature.

[0061] After testing, a coated steel wire for oil well detection cables with a tensile strength of 2440 MPa is obtained, and the neutral salt spray corrosion rate is 0.1662 g·m -2 ·h -1 , the coating structure is uniform and meets the detection requirements of a 1000 m oil well.

[0062] Comparative Example 1

[0063] The difference from Example 1 based on Example 1 is that the composition of the steel wire is designed as: C:Si:Mn:P:S:Cr:Fe = 0.72 wt.%:0.2 wt.%:0.2 wt.%:0.01 wt.%:0.01 wt.%:0.05 wt.%: balance. After testing, a coated steel wire for oil well detection cables with a tensile strength of 1900 MPa is obtained, and the neutral salt spray corrosion rate is 0.1752 g·m -2 ·h -1 , the coating structure is uniform and meets the detection requirements of a 6000 m oil well.

[0064] Comparative Example 2

[0065] The difference from Example 1 based on Example 1 is that step (6) is omitted. That is, only a pure zinc coating is hot-dip coated on the steel wire surface. After testing, a coated steel wire for oil well detection cables with a tensile strength of 2010 MPa is obtained, and the neutral salt spray corrosion rate is 0.2868 g·m -2 ·h -1 , the coating structure is uniform and meets the detection requirements of a 7000 m oil well.

[0066] Comparative Example 3

[0067] Differing from Example 1 based on Example 1, the cold drawing treatment of the galvanized steel wire in step (5) is omitted. That is, no cold drawing treatment is performed between the two hot-dip galvanizing processes. After testing, a coated steel wire for oil well detection cable with a tensile strength of 2000 MPa and a neutral salt spray corrosion rate of 0.1985 g·m -2 ·h -1 is obtained, and the coating structure is relatively uniform, meeting the detection requirements for 7000 m oil wells.

[0068] Comparative Example 4

[0069] Differing from Comparative Example 1 based on Comparative Example 1, the cold drawing treatment of the galvanized steel wire in step (5) is omitted. That is, no cold drawing treatment is performed between the two hot-dip galvanizing processes. After testing, a coated steel wire for oil well detection cable with a tensile strength of 2100 MPa and a neutral salt spray corrosion rate of 0.2756 g·m -2 ·h -1 is obtained, and cracking appears in the coating structure.

[0070] Comparative Example 5

[0071] Differing from Example 1 based on Example 1, in step (5), the temperature of hot-dip galvanizing is 470°C. After testing, a coated steel wire for oil well detection cable with a tensile strength of 2078 MPa and a neutral salt spray corrosion rate of 0.1953 g·m -2 ·h -1 is obtained, and the coating structure is relatively uniform, meeting the detection requirements for 7000 m oil wells.

[0072] Comparative Example 6

[0073] Differing from Example 1 based on Example 1, in step (6), the temperature of hot-dip Zn-Al-Mg is 460°C. After testing, a coated steel wire for oil well detection cable with a tensile strength of 2070 MPa and a neutral salt spray corrosion rate of 0.1958 g·m -2 ·h -1 is obtained, and the coating structure is relatively uniform, meeting the detection requirements for 7000 m oil wells.

[0074] Comparative Example 7

[0075] Differing from Example 1 based on Example 1, the time for both hot-dip galvanizing and hot-dip Zn-Al-Mg is 60 s. After testing, a coated steel wire for oil well detection cable with a tensile strength of 2080 MPa and a neutral salt spray corrosion rate of 0.1896 g·m -2 ·h -1, The coating structure is relatively uniform, meeting the detection requirements of 7000m oil wells.

Claims

1. A high-strength and high-corrosion-resistant steel wire for 10,000-meter oil well detection cable, characterized in that: The following elements are included in the mass ratio: C: 0.87 ~ 0.96 wt.%, Si: 0.5 ~ 0.7 wt.%, Mn: 0.5 ~ 0.7 wt.%, P: ≤ 0.01 wt.%, S: ≤ 0.01 wt.%, Cr: 0.3 ~ 0.6 wt.%, Ce: 0.05 ~ 0.15 wt.%, Fe: balance; The method for preparing the high-strength and high-corrosion-resistant steel wire for the 10,000-meter-class oil well detection cable comprises the following steps: (1) cold drawing a wire rod to obtain a cold drawn steel wire; the wire rod has a diameter of 5 to 6 mm; (2) subjecting the cold drawn steel wire to an austenitizing heat treatment and a quenching treatment to obtain a steel wire having a sorbite structure; (3) hot-dip-coating the steel wire obtained in step (2) with a pure zinc coating, and then cold-drawing and deforming the steel wire to obtain a galvanized steel wire; the diameter of the galvanized steel wire after the cold-drawing and deformation is 2.6 to 3.2 mm; the temperature of the hot-dip pure zinc coating is 440° C. to 460° C., and the time is 10 to 30 s; (4) A Zn-Al-Mg alloy coating is hot-dip coated on the surface of the cold-drawn galvanized steel wire, which is then cold-drawn to obtain the high-strength and high-corrosion-resistant steel wire for the 10,000-meter oil well detection cable; the temperature of the hot-dip Zn-Al-Mg alloy coating is 420°C to 450°C, and the time is 10 to 20 seconds.

2. A method for preparing the high-strength and high-corrosion-resistant steel wire for 10,000-meter-class oil well detection cable according to claim 1, characterized in that: The steps include: (1) cold drawing a wire rod to obtain a cold drawn steel wire; the wire rod has a diameter of 5 to 6 mm; (2) subjecting the cold drawn steel wire to an austenitizing heat treatment and a quenching treatment to obtain a steel wire having a sorbite structure; (3) hot-dip-coating the steel wire obtained in step (2) with a pure zinc coating, and then cold-drawing and deforming the steel wire to obtain a galvanized steel wire; the diameter of the galvanized steel wire after the cold-drawing and deformation is 2.6 to 3.2 mm; the temperature of the hot-dip pure zinc coating is 440° C. to 460° C., and the time is 10 to 30 s; (4) A Zn-Al-Mg alloy coating is hot-dip coated on the surface of the cold-drawn galvanized steel wire, which is then cold-drawn to obtain the high-strength and high-corrosion-resistant steel wire for the 10,000-meter oil well detection cable; the temperature of the hot-dip Zn-Al-Mg alloy coating is 420°C to 450°C, and the time is 10 to 20 seconds.

3. The method for preparing the high-strength and high-corrosion-resistant steel wire for the 10,000-meter-class oil well detection cable according to claim 2, characterized in that: In step (4), the mass fraction of Al in the Zn-Al-Mg alloy coating is 3 to 10 wt.%, the mass fraction of Mg is 1 to 6 wt.%, the mass fraction of Ce is 0.01 to 0.5 wt.%, and the rest is Zn.

4. The method for preparing the high-strength and high-corrosion-resistant steel wire for the 10,000-meter-class oil well detection cable according to claim 2, characterized in that: In step (4), after the cold drawing, the steel wire is kept at 265°C to 275°C for 30 to 60 minutes for stabilization treatment.

5. The method for preparing the high-strength and high-corrosion-resistant steel wire for the 10,000-meter-class oil well detection cable according to claim 2, characterized in that: In step (2), the austenitizing heat treatment temperature is 800°C to 850°C, and the time is 5 to 10 minutes.

6. The method for preparing the high-strength and high-corrosion-resistant steel wire for the 10,000-meter-class oil well detection cable according to claim 2, characterized in that: Before step (3), the steel wire is subjected to a flux plating treatment, and the flux plating agent composition is composed of ZnCl2: 10 ~ 20wt.%, NH4Cl: 5 ~ 15 wt.%, SnCl2: 5 ~ 15 wt.%, KCl: 2 ~ 8 wt.%, CeCl3: 0.1 ~ 1wt.%, CH3OH: 5 ~ 10 wt.%, and the rest is water; the flux plating temperature is 80℃ ~ 90℃, and the flux plating time is 1 ~ 3 min.