CN111733369A - Low-carbon manganese alloying solid expansion pipe and manufacturing method thereof - Google Patents

Abstract

The invention discloses a low-carbon manganese alloying solid expansion pipe and a manufacturing method thereof, wherein the proportioned alloy components are sequentially smelted, diffusion annealed, hot rolled, cold rolled or cold drawn and heat treated in the manufacturing process to prepare the low-carbon manganese alloying solid expansion pipe, the control of two-phase zone sub-temperature quenching treatment and high-temperature tempering treatment in the heat treatment is a key part for ensuring the performance of the pipe, in the processes of critical quenching treatment and high-temperature tempering, because the composition proportion of Mn and Ni is limited, a certain amount of Cr element is added, so that enough retained austenite can be obtained in the process of the two-phase zone sub-temperature quenching treatment, carbon elements and other alloy elements are redistributed in ferrite and austenite, thereby continuously improving the stability of austenite, and finally reserving the austenite at room temperature to obtain a ferrite + bainite + residual austenite structure.

Description

Low-carbon manganese alloying solid expansion pipe and manufacturing method thereof

[ technical field ] A method for producing a semiconductor device

The invention belongs to the field of solid expansion pipes, and particularly relates to a low-carbon manganese alloying solid expansion pipe material and a manufacturing method thereof.

[ background of the invention ]

Solid Expandable casing set (solid Expandable tubular) technology is a new drilling, completion and workover technique for radially expanding a particular casing to a desired diameter size in a wellbore with the goal of "saving" wellbore size.

The solid expansion tube technology has been successfully applied to commercialization, and the core technology mainly comprises: expansion pipe tubular product, expansion pipe screw thread, operation instrument and other supporting technologies, but its core content still is mastered by a few international big companies at present, and its technical transfer expense and product selling price are higher.

Conventional bushings should be elastically deformed during service, not allow macroscopic plastic deformation, which means that the structural member begins to fail when the material undergoes macroscopic plastic deformation. Therefore, for conventional casing, it is desirable that the material have a high yield strength and a certain plasticity to meet the requirement of safe service of the material while meeting the strength requirement. Therefore, the yield ratio of the common casing material is generally controlled to be 0.85-0.90.

Unlike conventional casing, the expansion pipe is in service after a certain amount of plastic deformation has occurred, so it is desirable that the pipe before expansion should have a low yield strength to reduce the expansion force during expansion operation, while having a large uniform plastic elongation to keep the expansion process within the uniform plastic deformation range of the pipe; after the expansion is finished, the expansion pipe has high yield strength so as to meet the requirements of the expansion pipe on pressure bearing and connection strength and a certain plasticity allowance so as to ensure the safe service of the material.

Comprehensive analysis shows that the expansion pipe has low yield strength, low yield ratio, excellent plasticity (especially uniform plastic deformation capacity), enough strain hardening capacity to ensure that the pipe deforms uniformly, high strength and satisfactory plastic toughness after expansion, and especially has almost completely opposite requirements on the strength of the pipe before and after expansion. Thus, the existing conventional casing is not suitable for use as a solid expansion pipe. In addition, due to the special use method of the expansion pipe, the requirement on the size precision of the pipe is higher than that of the common casing pipe, so that a novel expansion pipe is urgently needed to be designed to be suitable for application in drilling, well completion and well repair technologies.

[ summary of the invention ]

The invention aims to overcome the defects of the prior art and provide a low-carbon manganese alloying solid expansion pipe material and a manufacturing method thereof, so as to overcome the technical problems that the existing sleeve is not suitable for being used as a solid expansion pipe and cannot meet the requirements of high uniform elongation, high plasticity, low yield strength, low yield ratio and high dimensional precision.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a manufacturing method of a low-carbon manganese alloying entity expansion pipe comprises the following steps:

step 1, smelting the proportioned mixed alloy to prepare an ingot;

the mixed alloy comprises the following components in percentage by mass: c: 0.06-0.15%; cr: 0.20-0.50%; mn: 1.6-3.0%; si: 0.15-0.55%; ni: 0 to 1.0 percent; p is less than or equal to 0.01 percent; less than or equal to 0.01 percent of S and the balance of Fe; wherein the sum of the mass percentages of Mn and Ni is more than or equal to 2.5 percent;

step 2, carrying out diffusion annealing treatment on the ingot to obtain an annealed ingot;

step 3, the ingot subjected to annealing treatment is made into a seamless tube blank through hot rolling;

step 4, cold rolling or cold drawing the seamless tube blank to a target size to obtain a tube;

step 5, performing quenching treatment twice on the pipe, tempering, cooling the tempered pipe blank to room temperature, and straightening to obtain a low-carbon manganese alloying entity expansion pipe;

wherein the second quenching is double-phase zone sub-temperature quenching treatment, the temperature of the sub-temperature quenching treatment is 700-810 ℃, and the time of the sub-temperature quenching treatment is 30-90 min.

The invention is further improved in that:

preferably, in the step 2, the diffusion annealing temperature is 1200-1250 ℃, and the annealing time is 2-6 hours.

Preferably, in the step 5, the first quenching temperature is 880-930 ℃, and the first quenching heat preservation time is 30-90 min.

Preferably, in the step 5, the twice quenched tube blank is quenched by water to cool the tube blank to room temperature, and then tempered, wherein the tempering temperature is 560-700 ℃, and the tempering time is 30-90 min.

Preferably, in step 4, the seamless tube blank is subjected to a normalizing treatment before cold rolling or cold drawing.

The low-carbon manganese alloying solid expansion pipe material prepared by any one of the manufacturing methods comprises the following components in percentage by mass: 0.06-0.15%; cr: 0.20-0.50%; mn: 1.6-3.0%; si: 0.15-0.55%; ni: 0 to 1.0 percent; p is less than or equal to 0.01 percent; less than or equal to 0.01 percent of S and the balance of Fe; wherein the sum of the mass percent of Mn and Ni is more than or equal to 2.5 percent.

Preferably, the composition comprises the following components in percentage by mass: 0.07%, Cr: 0.25%, Mn: 2%, Si: 0.35%, Ni: 0.7%, P: 0.008%, S: 0.002%, and the balance of Fe.

Preferably, the pipe is further added with V: 0.02-0.06%, Nb: 0.01 to 0.03 percent.

Preferably, the composition comprises the following components in percentage by mass: 0.13%, Cr: 0.35%, Mn: 2.0%, Si: 0.40%, Ni: 0.45%, P: 0.009%, S: 0.004%, V: 0.03%, Nb: 0.02% and the balance Fe.

Preferably, in the metallographic structure of the low-carbon manganese alloying solid expansion pipe, the residual austenite accounts for 8-20% of the whole structure volume;

the total elongation of the low-carbon manganese alloying entity expansion pipe is more than or equal to 35%, the uniform elongation is more than or equal to 15%, the yield strength is 300-475 MPa, the tensile strength is 450-650 MPa, and the yield ratio is 0.5-0.73;

after 15% plastic deformation, the total elongation is more than or equal to 20%, the yield strength is 500-650 MPa, the tensile strength is 600-750 MPa, and the yield ratio is 0.75-0.90.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a method for manufacturing a low-carbon manganese alloying solid expansion pipe, which is used for producing a solid expansion pipe with excellent comprehensive properties such as high uniform elongation, high plasticity, low yield strength, low yield ratio, high dimensional accuracy and the like by limiting alloy components and adjusting a subsequent heat treatment process of a pipe blank. The manganese alloying design concept of the traditional petroleum casing is still used in the aspect of component design, the low-carbon low-alloy pipe does not contain noble metal elements, the existing hot-rolled steel pipe production line can be used for production, and the production cost of the pipe is favorably controlled; in the manufacturing process, the proportioned alloy components are sequentially subjected to smelting, annealing, hot rolling, cold rolling or cold drawing and heat treatment to prepare the low-carbon manganese alloying entity expansion pipe, wherein the pipe blank is subjected to cold rolling or cold drawing processing to realize high precision of the pipe size; in the heat treatment, the control of the two-phase zone sub-temperature quenching treatment, namely critical quenching and high-temperature tempering treatment is a key part for ensuring the performance of the pipe, and in the critical quenching treatment and the high-temperature tempering process, because the composition proportion of Mn and Ni is limited, enough residual austenite can be obtained in the two-phase zone sub-temperature quenching treatment process, and carbon elements and other alloy elements are redistributed in ferrite and austenite, so that the stability of the austenite is continuously improved, and finally the austenite is retained at room temperature to obtain a ferrite, bainite and residual austenite structure. The pipe manufactured by the method meets the characteristics of low yield strength before expansion, excellent plasticity, high yield strength after expansion and good toughness, and ensures that the pipe obtains ideal performance.

Furthermore, firstly, the ingot is subjected to diffusion annealing treatment to improve the segregation of alloy elements in the ingot.

Further, the ingot after annealing needs to be subjected to quenching treatment after hot rolling tube penetration and cold rolling/cold drawing to form a tube blank, the first quenching is complete quenching, the quenching temperature is 880-930 ℃, and the effect of improving the microstructure is mainly achieved; the second quenching is a sub-temperature quenching in the two-phase region, which is to obtain a ferrite + martensite two-phase structure and prepare the structure for obtaining enough residual austenite.

Further, tempering the tube blank after the second water quenching so that martensite is decomposed in the tempering process, and residual austenite can be formed between original martensite sheet layers and at ferrite grain boundaries.

Furthermore, normalizing treatment is carried out before cold rolling or cold drawing to improve the plasticity of the pipe, eliminate stress and deformation tissues generated by hot working and be beneficial to cold drawing/cold rolling of the pipe.

The invention also discloses a low-carbon manganese alloyed solid expansion pipe, which is characterized in that on the basis of the existing low-carbon low-alloy pipe, precious metals are not added, the mass percentage content of Mn and Ni is limited, and meanwhile, a certain Cr element is added to promote the formation of residual austenite, so that the final finished pipe takes ferrite as a matrix and contains structures such as bainite and residual austenite, and the like, and has the characteristics of high uniform elongation, high plasticity, low yield strength, low yield ratio, high dimensional precision and the like. The final pipe has high yield strength, high work hardening capacity and high uniform deformation capacity, and the whole pipe can meet the service requirement.

Furthermore, in the manufactured tube blank, the residual austenite accounts for 8-20% of the whole structure, has enough thermodynamic stability and can stably exist at the temperature of more than 50 ℃ below zero; the solid expansion pipe material has the characteristics of high uniform elongation, high plasticity, low yield strength and low yield ratio before expansion: the total elongation is more than or equal to 35 percent, the uniform elongation is more than or equal to 15 percent, the yield strength is 300-475 MPa, the tensile strength is 450-650 MPa, and the yield ratio is 0.5-0.73. After plastic deformation of about 15%, the pipe has high strength and enough plasticity, the total elongation is more than or equal to 20%, the yield strength reaches 500-650 MPa, the tensile strength reaches 600-750 MPa, the yield ratio is 0.75-0.90, and the pipe meets the characteristics of low yield strength before expansion, excellent plasticity, high yield strength after expansion and good plasticity.

[ description of the drawings ]

FIG. 1 is a metallographic structure of the finished pipe of the present invention;

FIG. 2 is an EBSD map of the retained austenite distribution in the finished pipe structure of the present invention;

FIG. 3 is a diagram of the result of XRD quantitative analysis of the volume fraction of retained austenite in the finished tube structure.

[ detailed description ] embodiments

The invention is described in further detail below with reference to the accompanying drawings:

in the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly and encompass, for example, both fixed and removable connections; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention discloses a low-carbon manganese alloy entity expansion pipe and a manufacturing method thereof, and in order to enable the pipe to generate a TRIP effect, the low-carbon manganese alloy entity expansion pipe comprises the following components in percentage by mass: c: 0.06-0.15%; cr: 0.10-0.35%; mn: 1.6-3.0%; si: 0.15-0.65%; ni: 0 to 1.0 percent; p is less than or equal to 0.01 percent; s is less than or equal to 0.01 percent, the balance is Fe, and V: 0.02-0.06%, Nb: 0.01-0.03%; the sum of the mass percent of Mn and Ni is more than or equal to 2.5 percent, enough retained austenite can be obtained, and the ideal performance of the pipe can be ensured. The components of the invention are all in mass percent and are not described in detail below.

Preferably, there are two classes of ingredients: c: 0.07%, Cr: 0.25%, Mn: 2%, Si: 0.35%, Ni: 0.7%, P: 0.008%, S: 0.002%, and the balance Fe.

C: 0.13%, Cr: 0.25%, Mn: 2.5%, Si: 0.40%, Ni: 0.45%, P: 0.009%, S: 0.004%, V: 0.03%, Nb: 0.02% and the balance Fe.

Meanwhile, the invention provides a manufacturing method of the low-carbon manganese alloying entity expansion pipe, which comprises the following steps:

1) smelting and casting the alloy components with the well-proportioned components in a converter or an electric furnace to prepare an ingot;

2) carrying out homogenization annealing treatment on the cast ingot at the temperature of 1200-1250 ℃ for 2-6 hours;

3) hot rolling is adopted to make the ingot subjected to annealing treatment into a seamless tube blank;

4) normalizing the tube blank manufactured by hot rolling, and then cold rolling or cold drawing to a target size; the cold deformation process is suitable for ensuring that the pipe has better geometric dimension precision;

5) heat treating the tube blank

5.1) quenching the cold-rolled or cold-drawn tube blank at the temperature of 880-930 ℃;

5.2) heating the quenched tube blank to a temperature between Ac1 and Ac3, namely a gamma + alpha double-phase region, and performing sub-temperature quenching treatment, wherein the temperature is selected to be 20-40 ℃ below 1/2(Ac1+ Ac3), namely the heating treatment temperature is 700-810 ℃, and the heat preservation time is 30-90 min for the expanded tube blank with the thickness of 5-20 mm;

5.3) after the heat preservation is finished, the tube blank is rapidly cooled to the room temperature in a water quenching mode, and the tube blank obtains a ferrite and martensite dual-phase structure;

and 5.4) heating the tube blank again to 560-740 ℃ for high-temperature tempering, wherein the tempering time is 30-90 min, martensite is decomposed in the tempering process, and retained austenite is formed between original martensite lamella and at ferrite grain boundary.

5.5) after the high-temperature tempering is finished, the mechanical property of the tube blank can be adjusted by adopting different cooling modes such as air cooling, furnace cooling and the like, and the secondary adjustment of the strength and the plasticity of the tube can be realized.

The invention adopts manganese element alloying, and is matched with a special heat treatment process to ensure that the steel obtains a certain amount of retained austenite, the retained austenite generates martensite phase transformation under the action of an external load, namely, the uniform plasticity and the strength of the expansion pipe are improved through a transformation induced plasticity (TRIP) mechanism. The performance requirements of the expansion pipe on low yield before expansion and high yield after expansion of the pipe are effectively met.

The carbon is an austenite stabilizing element, the carbon content cannot be too low, the stability of the retained austenite is reduced due to too low carbon content, but the strength of the pipe is increased and the toughness and weldability are reduced due to too high carbon content, so that the carbon content of the pipe is controlled to be 0.06-0.15%. Cr is a ferrite-forming element, and is dissolved in ferrite to improve the strength of ferrite and the hardenability of steel, thereby being beneficial to the production of thick-wall pipes, and simultaneously, the Cr can promote the formation of residual austenite in the steel. Si can prevent cementite from being precipitated, so that the stability of the retained austenite is ensured, and the ferrite matrix can be strengthened. Mn is an austenite stabilizing element, and when the content of the Mn element reaches 2.5 percent, martensite formed by quenching forms flaky residual austenite along the edge of the martensite in the high-temperature tempering process, so that the requirement of the traditional TRIP steel on high cooling rate is avoided, and the method has technical advantages in manufacturing large-wall-thickness pipes. Similar to Mn element, Ni element is also an austenite forming element, and alloying by replacing Mn element with partial Ni element can effectively reduce Mn element segregation, and meanwhile, Ni element can effectively improve the toughness of steel materials. In addition, the too high yield strength of the expansion pipe is not beneficial to the starting of the expansion deformation of the pipe, and after the expansion pipe generates the expansion deformation, the strength of the pipe is improved due to the work hardening effect generated by the TRIP effect, so that the mechanical property requirement of the pipe can be met.

In order to ensure that a pipe body has a fine and uniform microstructure when a large-wall-thickness pipe is produced, the addition of the strong carbide forming element V, Nb can play a role in refining grains, V, Nb can generate high-stability carbide to reduce C elements dissolved into austenite and reduce the stability of the austenite, so that the volume fraction of residual austenite obtained at room temperature is reduced, and therefore, the C content is correspondingly increased when a trace V, Nb is added to ensure that enough residual austenite is obtained. By adding an appropriate amount of V, Nb and matching with a corresponding rolling process and a controlled cooling process, a pipe with finer structure and more excellent comprehensive performance can be obtained. Reasonable component design is the basis for obtaining the TRIP effect, and a reasonable heat treatment process is the key for realizing the TRIP effect. In addition, since the expanded pipe requires a better geometric dimensional accuracy than the conventional sleeve, the final forming process of the pipe employs a cold rolling or drawing process to obtain a satisfactory dimensional accuracy.

The solid expansion pipe material has a complex phase structure of ferrite, bainite and residual austenite, wherein the residual austenite accounts for 8-20% of the whole structure, has enough thermodynamic stability and can stably exist at the temperature of more than 50 ℃ below zero. The solid expansion pipe has the characteristics of high uniform elongation, high plasticity, low yield strength, low yield ratio and the like before expansion: the total elongation is more than or equal to 35 percent, the uniform elongation is more than or equal to 15 percent, the yield strength is 300-475 MPa, the tensile strength is 450-650 MPa, and the yield ratio is 0.5-0.73. After plastic deformation of about 15%, the material has high strength and enough plasticity, the total elongation is more than or equal to 20%, the yield strength reaches 500-650 MPa, the tensile strength reaches 600-750 MPa, the yield ratio is 0.75-0.90, and the design targets of low yield strength before expansion, excellent plasticity, high yield strength after expansion and good plasticity are met. The maximum thickness of the pipe wall of the expansion pipe can reach 20mm, and the expansion pipe has good internal pressure strength and collapse resistance.

The manufacturing method of the invention adopts the hot rolling process to manufacture the tube blank, then the finished tube blank is manufactured by the cold rolling or cold drawing process, the finished tube blank is manufactured into the finished product of the expansion tube after the sub-temperature quenching and the high-temperature tempering heat treatment, and the finished product of the expansion tube can be used for repairing and patching the casing damage of the oil well and the emergency casing in the drilling process, can be used after the expansion deformation in the well, and has excellent comprehensive mechanical property.

The method comprises the following steps of (1) performing two-phase zone sub-temperature quenching heat treatment, namely critical quenching, and controlling high-temperature tempering treatment, wherein the control of the two-phase zone sub-temperature quenching heat treatment, namely critical quenching and the high-temperature tempering treatment is a key technology for ensuring the performance of a pipe, and in the processes of the critical quenching treatment and the high-temperature tempering, carbon elements and other alloy elements are redistributed in ferrite and austenite, so that the stability of the austenite is continuously improved, and finally the austenite is reserved at room temperature to obtain a ferrite + bainite + residual austenite structure; reasonable component design is the basis for obtaining the TRIP effect, and a reasonable heat treatment process is the key for realizing the TRIP effect. In addition, cold rolling or cold drawing processes are used to obtain satisfactory dimensional accuracy of the pipe.

Example 1:

the steel alloy material for the solid expandable casing pipe of the oil and gas well comprises the following components in percentage by mass: c: 0.07%, Cr: 0.25%, Mn: 1.6%, Ni: 1.0%, Si: 0.15%, P: 0.008%, S: 0.002%, and the balance Fe.

The manufacturing method of the oil and gas well solid expandable casing pipe comprises the following steps:

1) and C: 0.07%, Cr: 0.25%, Mn: 1.6%, Ni: 1.0%, Si: 0.15%, P: 0.008%, S: 0.002% of Fe and the balance of Fe, and smelting and casting steel to prepare an ingot;

2) carrying out homogenization annealing treatment on the cast ingot at 1250 ℃ for 2 hours;

3) making the annealed cast ingot into a tube blank by a hot rolling tube penetrating process;

4) the tube blank is normalized and then is made into a specified size phi 108mm multiplied by 8.32mm by a cold rolling process;

5) heat treating the tube blank

The tube blank is heated to 900 ℃ and then quenched, and then the tube blank is heated again to a temperature between Ac1 and Ac3, namely a gamma + alpha two-phase region, the heating temperature is 730 +/-20 ℃, and the heat preservation time is 45min for the tube with the thickness of 8.32 mm; after the heat preservation is finished, water quenching the tube blank to room temperature; and heating the quenched pipe blank to 650 +/-20 ℃ again for high-temperature tempering, wherein the tempering time is 60min, after the high-temperature tempering and heat preservation are finished, cooling the pipe blank in a furnace to 300 ℃, and then cooling the pipe blank in air to room temperature to finish the preparation of the solid expansion pipe.

Referring to fig. 1 and 2, it can be seen that a large amount of uniform retained austenite is formed at the grain boundaries in the finished pipe, and as can be seen from fig. 3, the retained austenite content of the pipe prepared in this example is 10.4%, indicating that retained austenite is formed in the final pipe.

The expansion pipe has the characteristics of: the uniform elongation of the solid expansion pipe before expansion deformation is 28%, the total elongation is 45%, the yield strength is 320MPa, the tensile strength is 560MPa, and the yield ratio is 0.57; after 14% of expansion deformation, the yield strength is 542MPa, the tensile strength is 646MPa, the yield ratio is 0.84, the uniform elongation is 10%, and the total elongation is 28%; the expansion pipe has good dimensional accuracy, and the external pressure and crushing resistance of the pipe body is 35 MPa.

Example 2:

the steel alloy material for the solid expandable casing pipe of the oil and gas well comprises the following components in percentage by mass: c: 0.13%, Cr: 0.25%, Mn: 2.5%, Ni: 0.45%, Si: 0.40%, P: 0.009%, S: 0.004%, Nb: 0.02%, V: 0.03 percent and the balance of Fe.

The manufacturing method of the oil and gas well solid expandable casing pipe comprises the following steps:

1) and C: 0.13%, Cr: 0.25%, Mn: 2.5%, Ni: 0.45%, Si: 0.40%, P: 0.009%, S: 0.004%, Nb: 0.02%, V: 0.03 percent of Fe and the balance of alloy components are subjected to steel smelting and casting to prepare an ingot;

2) carrying out homogenization annealing treatment on the cast ingot at 1200 ℃ for 6 hours;

3) making the annealed cast ingot into a tube blank by a hot rolling tube penetrating process;

4) the tube blank is normalized and then is made into a seamless steel tube with the specified size phi 194mm multiplied by 12mm by a cold rolling process.

5) Heat treating the tube blank

Heating the seamless steel pipe to 900 +/-10 ℃ for quenching treatment, wherein the quenching medium is water, then heating the steel pipe to a temperature between Ac1 and Ac3, namely a gamma + alpha two-phase zone, wherein the heating temperature is 740 +/-20 ℃, and keeping the temperature of an expansion pipe with the thickness of 12mm for 75 min; after the heat preservation is finished, water quenching the steel pipe to room temperature; and heating the quenched steel pipe to 650 +/-30 ℃ again for high-temperature tempering, wherein the tempering time is 90min, and after the high-temperature tempering is finished, air cooling to room temperature to finish the preparation of the solid expansion pipe.

The expansion pipe has the following performance characteristics: the content of retained austenite is 15%, the uniform elongation of the solid expandable casing before expansion deformation is 24%, the total elongation is 47%, the yield strength is 435MPa, the tensile strength is 620MPa, and the yield ratio is 0.70; after 15% of expansion deformation, the yield strength is 610MPa, the tensile strength is 725MPa, the yield ratio is 0.84, the uniform elongation is 6%, and the total elongation is 30%; the expansion pipe has good dimensional accuracy, and the external pressure and crushing resistance strength of the pipe body is 28 MPa.

Example 3

The steel alloy material for the solid expandable casing pipe of the oil and gas well comprises the following components in percentage by mass: c: 0.06%, Cr: 0.3%, Mn: 2.2%, Ni: 0.8%, Si: 0.15%, P: 0.005%, S: 0.0035 percent and the balance of Fe.

The manufacturing method of the oil and gas well solid expandable casing pipe comprises the following steps:

1) and C: 0.06%, Cr: 0.3%, Mn: 2.2%, Ni: 0.8%, Si: 0.60%, P: 0.005%, S: 0.0035 percent of Fe and the balance of alloy components are subjected to steel smelting and casting to prepare an ingot;

2) carrying out homogenization annealing treatment on the cast ingot at 1210 ℃ for 3 hours;

3) making the annealed cast ingot into a tube blank by a hot rolling tube penetrating process;

4) the tube blank is normalized and then is made into a seamless steel tube with the specified size phi 219mm multiplied by 12mm by a cold rolling process.

5) Heat treating the tube blank

Heating the seamless steel pipe to 920 +/-10 ℃ for quenching treatment, wherein the quenching medium is water, and then heating the seamless steel pipe to a temperature between Ac1 and Ac3, namely a gamma + alpha double-phase zone, wherein the heating temperature is 760 +/-20 ℃, and the heat preservation time is 85 min; after the heat preservation is finished, water quenching the steel pipe to room temperature; and heating the quenched steel pipe to 680 +/-30 ℃ again for high-temperature tempering, wherein the tempering time is 90min, and after the high-temperature tempering is finished, air cooling to room temperature to finish the preparation of the solid expansion pipe.

The expansion pipe has the following performance characteristics: the content of retained austenite is 12%, the uniform elongation of the solid expandable casing before expansion deformation is 26%, the total elongation is 49%, the yield strength is 300MPa, the tensile strength is 500MPa, and the yield ratio is 0.60; after 15% of expansion deformation, the yield strength is 560MPa, the tensile strength is 630MPa, the yield ratio is 0.88, and the total elongation is 32%. The external extrusion damage resistance strength of the pipe body is 22 MPa.

Example 4

The steel alloy material for the solid expandable casing pipe of the oil and gas well comprises the following components in percentage by mass: c: 0.15%, Cr: 0.2%, Mn: 2.1%, Ni: 0.7%, Si: 0.50%, P: 0.004%, S: 0.0025%, Nb: 0.01%, V: 0.02% and the balance Fe.

The manufacturing method of the oil and gas well solid expandable casing pipe comprises the following steps:

1) and C: 0.15%, Cr: 0.2%, Mn: 2.1%, Ni: 0.7%, Si: 0.50%, P: 0.004%, S: 0.0025%, Nb: 0.02%, V: 0.03 percent of Fe and the balance of alloy components are subjected to steel smelting and casting to prepare an ingot;

2) carrying out homogenization annealing treatment on the cast ingot at the temperature of 1220 ℃ for 4 hours;

3) making the annealed cast ingot into a tube blank by a hot rolling tube penetrating process;

4) the tube blank is normalized and then manufactured into a seamless steel tube with the specified size phi of 244.5mm multiplied by 13.84mm by a cold rolling process.

5) Heat treating the tube blank

Heating the seamless steel pipe to 880 +/-10 ℃ for quenching treatment, wherein the quenching medium is water, and then heating the steel pipe to between Ac1 and Ac3, namely a gamma + alpha double-phase region, wherein the heating temperature is 780 +/-20 ℃, and the heat preservation time is 90 min; after the heat preservation is finished, water quenching the steel pipe to room temperature; and heating the quenched steel pipe to 600 +/-30 ℃ again for high-temperature tempering, wherein the tempering time is 90min, and after the high-temperature tempering is finished, air cooling to room temperature to finish the preparation of the solid expansion pipe.

The expansion pipe has the following performance characteristics: the content of retained austenite is 10%, the uniform elongation of the solid expandable casing before expansion deformation is 17%, the total elongation is 45%, the yield strength is 475MPa, the tensile strength is 650MPa, and the yield ratio is 0.73; after 15% of expansion deformation, the yield strength is 650MPa, the tensile strength is 750MPa, the yield ratio is 0.86, and the total elongation is 23%. The external extrusion damage resistance strength of the pipe body is 23 MPa.

Example 5

The steel alloy material for the solid expandable casing pipe of the oil and gas well comprises the following components in percentage by mass: c: 0.08%, Cr: 0.35%, Mn: 2.3%, Ni: 0.6%, Si: 0.40%, P: 0.003%, S: 0.006%, Nb: 0.03 percent and the balance of Fe.

The manufacturing method of the oil and gas well solid expandable casing pipe comprises the following steps:

1) and C: 0.08%, Cr: 0.35%, Mn: 2.3%, Ni: 0.6%, Si: 0.40%, P: 0.003%, S: 0.006%, Nb: 0.03 percent of Fe and the balance of alloy components are subjected to steel smelting and casting to prepare an ingot;

2) carrying out homogenization annealing treatment on the ingot at the temperature of 1230 ℃ for 5 hours;

3) making the annealed cast ingot into a tube blank by a hot rolling tube penetrating process;

4) the tube blank is normalized and then is made into a seamless steel tube with the specified size phi of 140mm multiplied by 7mm by a cold rolling process.

5) Heat treating the tube blank

Heating the seamless steel pipe to 900 +/-10 ℃ for quenching treatment, wherein the quenching medium is water, and then heating the seamless steel pipe to a temperature between Ac1 and Ac3, namely a gamma + alpha double-phase zone, wherein the heating temperature is 760 +/-20 ℃, and the heat preservation time is 30 min; after the heat preservation is finished, water quenching the steel pipe to room temperature; and heating the quenched steel pipe to 600 +/-30 ℃ again for high-temperature tempering, wherein the tempering time is 60min, and after the high-temperature tempering is finished, air cooling to room temperature to finish the preparation of the solid expansion pipe.

The expansion pipe has the following performance characteristics: the content of retained austenite is 8%, the uniform elongation of the solid expandable casing before expansion deformation is 18%, the total elongation is 38%, the yield strength is 330MPa, the tensile strength is 580MPa, and the yield ratio is 0.57; after 15% of expansion deformation, the yield strength is 510MPa, the tensile strength is 645MPa, the yield ratio is 0.79, and the total elongation is 22%. The external pressure and crushing strength of the pipe body is 25 MPa.

Example 6

The steel alloy material for the solid expandable casing pipe of the oil and gas well comprises the following components in percentage by mass: c: 0.09%, Cr: 0.2%, Mn: 2.8%, Ni: 0.5%, Si: 0.30%, P: 0.007%, S: 0.007%, V: 0.0% and the balance Fe.

The manufacturing method of the oil and gas well solid expandable casing pipe comprises the following steps:

1) and C: 0.09%, Cr: 0.1%, Mn: 1.8%, Ni: 0.5%, Si: 0.30%, P: 0.007%, S: 0.007%, V: 0.02 percent of Fe and the balance of alloy components are subjected to steel smelting and casting to prepare an ingot;

2) carrying out homogenization annealing treatment on the cast ingot at the temperature of 1240 ℃ for 3.5 hours;

3) making the annealed cast ingot into a tube blank by a hot rolling tube penetrating process;

4) the tube blank is normalized and then is made into a seamless steel tube with the specified size phi of 114mm multiplied by 8mm by a cold rolling process.

5) Heat treating the tube blank

Heating the seamless steel pipe to 910 +/-10 ℃ for quenching treatment, wherein the quenching medium is water, and then heating the steel pipe to a temperature between Ac1 and Ac3, namely a gamma + alpha double-phase zone, wherein the heating temperature is 720 +/-20 ℃, and the heat preservation time is 40 min; after the heat preservation is finished, water quenching the steel pipe to room temperature; and heating the quenched steel pipe to 590 +/-30 ℃ again for high-temperature tempering, wherein the tempering time is 30min, and after the high-temperature tempering is finished, air cooling to room temperature to finish the preparation of the solid expansion pipe.

The expansion pipe has the following performance characteristics: the content of retained austenite is 20%, the uniform elongation of the solid expandable casing before expansion deformation is 18%, the total elongation is 50%, the yield strength is 300MPa, the tensile strength is 520MPa, and the yield ratio is 0.57; after 15% of expansion deformation, the yield strength is 535MPa, the tensile strength is 600MPa, the yield ratio is 0.9, and the total elongation is 36%. The external pressure and crushing strength of the pipe body is 35 MPa.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. The manufacturing method of the low-carbon manganese alloying entity expansion pipe is characterized by comprising the following steps of:

step 1, smelting the proportioned mixed alloy to prepare an ingot;

the mixed alloy comprises the following components in percentage by mass: c: 0.06-0.15%; cr: 0.20-0.50%; mn: 1.6-3.0%; si: 0.15-0.55%; ni: 0 to 1.0 percent; p is less than or equal to 0.01 percent; less than or equal to 0.01 percent of S and the balance of Fe; wherein the sum of the mass percentages of Mn and Ni is more than or equal to 2.5 percent;

step 2, carrying out diffusion annealing treatment on the ingot to obtain an annealed ingot;

step 3, the ingot subjected to annealing treatment is made into a seamless tube blank through hot rolling;

step 4, cold rolling or cold drawing the seamless tube blank to a target size to obtain a tube;

step 5, performing quenching treatment twice on the pipe, tempering, cooling the tempered pipe blank to room temperature, and straightening to obtain a low-carbon manganese alloying entity expansion pipe;

wherein the second quenching is double-phase zone sub-temperature quenching treatment, the temperature of the sub-temperature quenching treatment is 700-810 ℃, and the time of the sub-temperature quenching treatment is 30-90 min.

2. The method for manufacturing the low-carbon manganese alloying solid expansion pipe material as claimed in claim 1, wherein in the step 2, the diffusion annealing temperature is 1200-1250 ℃ and the annealing time is 2-6 hours.

3. The manufacturing method of the low-carbon manganese alloying solid expansion pipe material as claimed in claim 1, wherein in the step 5, the first quenching temperature is 880-930 ℃, and the first quenching heat preservation time is 30-90 min.

4. The method for manufacturing the low-carbon manganese-alloyed solid expansion pipe material as claimed in claim 1, wherein in the step 5, the twice-quenched pipe blank is water-quenched to cool the pipe blank to room temperature, and then tempered, wherein the tempering temperature is 560-700 ℃ and the tempering time is 30-90 min.

5. The method for manufacturing the low-carbon manganese-alloyed solid expansion tube material as claimed in claim 1, wherein in the step 4, the normalizing treatment is performed before the cold rolling or the cold drawing of the seamless tube blank.

6. A low-carbon manganese alloying solid expansion pipe material prepared by the manufacturing method of any one of claims 1 to 5 is characterized by comprising the following components in percentage by mass, C: 0.06-0.15%; cr: 0.20-0.50%; mn: 1.6-3.0%; si: 0.15-0.55%; ni: 0 to 1.0 percent; p is less than or equal to 0.01 percent; less than or equal to 0.01 percent of S and the balance of Fe; wherein the sum of the mass percent of Mn and Ni is more than or equal to 2.5 percent.

7. The low-carbon manganese-alloyed solid expansion pipe material as claimed in claim 6, wherein the low-carbon manganese-alloyed solid expansion pipe material comprises the following components in percentage by mass, C: 0.07%, Cr: 0.25%, Mn: 2%, Si: 0.35%, Ni: 0.7%, P: 0.008%, S: 0.002%, and the balance of Fe.

8. The low carbon manganese alloyed solid expansion pipe material according to claim 6, wherein said pipe material further comprises, in mass percent, V: 0.02-0.06%, Nb: 0.01 to 0.03 percent.

9. The low-carbon manganese alloy materialized expansion pipe material of claim 8, which is characterized by comprising the following components in percentage by mass, C: 0.13%, Cr: 0.35%, Mn: 2.0%, Si: 0.40%, Ni: 0.45%, P: 0.009%, S: 0.004%, V: 0.03%, Nb: 0.02% and the balance Fe.

10. The low carbon manganese alloyed solid expansion pipe material of claim 6,

in the metallographic structure of the low-carbon manganese alloying entity expansion pipe, the residual austenite accounts for 8-20% of the whole structure volume;

the total elongation of the low-carbon manganese alloying entity expansion pipe is more than or equal to 35%, the uniform elongation is more than or equal to 15%, the yield strength is 300-475 MPa, the tensile strength is 450-650 MPa, and the yield ratio is 0.50-0.73;

after 15% plastic deformation, the total elongation is more than or equal to 20%, the yield strength is 500-650 MPa, the tensile strength is 600-750 MPa, and the yield ratio is 0.75-0.90.

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