CN115961216B - Submarine oil and gas transmission pipeline and preparation method thereof - Google Patents
Submarine oil and gas transmission pipeline and preparation method thereof Download PDFInfo
- Publication number
- CN115961216B CN115961216B CN202310114232.9A CN202310114232A CN115961216B CN 115961216 B CN115961216 B CN 115961216B CN 202310114232 A CN202310114232 A CN 202310114232A CN 115961216 B CN115961216 B CN 115961216B
- Authority
- CN
- China
- Prior art keywords
- stainless steel
- molten liquid
- submarine oil
- treatment
- solid solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a submarine oil and gas pipeline and a preparation method thereof. The submarine oil and gas transmission pipeline is made of austenitic stainless steel and comprises the following element components in percentage by mass: 14.0-19.0% of Mn, 16.0-21.0% of Cr, 0.5-1.0% of N, less than or equal to 0.60% of Si, 1.0-1.5% of Al, 2.0-3.0% of Mo, 0.3-1.0% of Nb, 0.5-1.5% of Nd, 1.0-2.0% of Ta, 0.2-0.5% of Y, 0.002-0.0028% of B, less than or equal to 0.015% of P, less than or equal to 0.02% of C, less than or equal to 0.015% of S, less than or equal to 0.005% of O, and the balance of Fe and unavoidable impurities. The submarine oil and gas pipeline prepared by the method has good mechanical property and corrosion resistance, and can effectively prolong the service life of the oil and gas pipeline on the seabed.
Description
Technical Field
The invention relates to the technical field of pipelines, in particular to a submarine oil and gas pipeline and a preparation method thereof.
Background
With the rapid development of economy and technology, people have never stopped exploring the steps of the ocean. The super austenitic stainless steel has excellent corrosion resistance and good mechanical property, and is widely applied to ocean resource development. Seawater contains a large amount of corrosive mineral elements, and has great influence on the corrosion resistance of the submarine oil and gas pipeline. The main component of the seawater is sodium chloride, and the sodium chloride is also a strong electrolyte, and the sodium chloride is dissolved in the seawater to generate chloride ions, so that the chloride ions have self-catalysis effect, and the corrosion speed of metal is further accelerated. The main corrosion modes of the submarine oil and gas transmission pipeline in the corrosive medium are corrosion outside the pipe and corrosion inside the pipe. Among them, marine atmospheric corrosion, seawater corrosion and sea mud corrosion are three corrosion conditions for corrosion outside the pipe. Of these three types of corrosion, seawater corrosion is the most severe corrosion to pipeline steel.
Chinese patent (application number: 201911207231.9) discloses an austenitic stainless steel, a fine-grain large-size bar, a preparation method and application thereof. The stainless steel comprises the following chemical components in percentage by weight: less than or equal to 0.030 percent of C, less than or equal to 0.01 percent of S, less than or equal to 0.02 percent of P, less than or equal to 1.00 percent of Si, less than or equal to 2.00 percent of Mn, 0.14 to 0.22 percent of N, 17.50 to 19.50 percent of Cr and 9.50 to 12.50 percent of Ni; the balance of Fe and unavoidable other impurities. The austenitic stainless steel prepared by the method has good intergranular corrosion resistance, and the tensile strength is not lower than 600MPa. Although the austenitic stainless steel of the invention has good corrosion performance, the mechanical properties of the austenitic stainless steel of the invention are still to be mentioned, and the service life of the austenitic stainless steel can be prolonged.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a submarine oil and gas pipeline and a preparation method thereof.
In order to solve the technical problems, the invention adopts the following technical scheme:
the submarine oil and gas transmission pipeline comprises the following element components in percentage by mass: 14.0-19.0% of Mn, 16.0-21.0% of Cr, 0.5-1.0% of N, less than or equal to 0.60% of Si, 1.0-1.5% of Al, 2.0-3.0% of Mo, 0.3-1.0% of Nb, 0.5-1.5% of Nd, 1.0-2.0% of Ta, 0.2-0.5% of Y, 0.002-0.0028% of B, less than or equal to 0.015% of P, less than or equal to 0.02% of C, less than or equal to 0.015% of S, less than or equal to 0.005% of O, and the balance of Fe and unavoidable impurities.
Preferably, the submarine oil and gas transmission pipeline comprises the following element components in percentage by mass: 15.0-18.0% of Mn, 18.0-20.0% of Cr, 0.6-0.9% of N, 0.2-0.5% of Si, 1.1-1.4% of Al, 2.2-2.8% of Mo, 0.5-1.0% of Nb, 0.8-1.2% of Nd, 1.2-1.8% of Ta, 0.25-0.45% of Y, 0.0022-0.0027% of B, 0.008-0.012% of P, 0.01-0.018% of C, 0.008-0.014% of S, 0.001-0.004% of O, and the balance of Fe and unavoidable impurities.
The submarine oil and gas transmission pipeline is made of austenitic stainless steel.
The effects and control amounts of all elements of the submarine oil and gas pipeline prepared by the invention are as follows:
mn: manganese is an austenite forming element, has the effect of stabilizing an austenite structure, meanwhile, the solubility of nitrogen in steel is very low, the addition of manganese can improve the solubility of nitrogen in steel, manganese can also form manganese sulfide with sulfur impurities in molten steel, the harmful effect of residual sulfur in steel is eliminated, but the generation of excessive nonmetallic inclusion manganese sulfide can influence the strength and corrosion resistance of steel to a certain extent, passivation films at the junction of a steel substrate and Mn S are weak, corrosion preferentially occurs from an interface, and finally the failure of parts is caused. Meanwhile, the material used in the marine environment can be corroded by Mn S nonmetallic inclusion and marine microorganisms; therefore, the content of manganese in the high-strength corrosion-resistant ocean engineering stainless steel is limited to be 14.0-19.0%.
Cr: the main elements in austenitic stainless steel mainly play a role in improving the corrosion resistance and oxidation resistance of the stainless steel, and researches show that a stable passivation film which protects the steel from atmospheric corrosion can be formed only when the steel contains 10.5% of Cr at least. The corrosion resistance of stainless steel increases with increasing Cr content. However, too high Cr content promotes the formation of harmful phases, reduces the hot workability of stainless steel, and also easily causes the occurrence of metal segregation during smelting, so the Cr content is controlled to be 16.0-21.0%.
N: the method can stabilize the austenitic structure, partially replace the use of austenitic stainless steel nickel, delay carbide precipitation and improve intergranular corrosion resistance, but the solubility of nitrogen in stainless steel is not high, and excessive addition can lead to nitrogen precipitation, and the addition of the manganese element is controlled to improve the addition of nitrogen in the stainless steel to 0.5-1.0%.
Si: the silicon element is added into the stainless steel, so that oxygen impurities in the steel can be effectively removed, and compact SiO (silicon oxide) can be produced on the surface of the stainless steel 2 The oxidation film improves the oxidation resistance of the material and improves the corrosion resistance to chloride ions, but silicon is a ferrite forming element, and the excessive addition amount can influence the formation of an austenite structure of the material, so that the silicon content is limited to be less than or equal to 0.60 percent.
Al: aluminum is added into austenitic stainless steel as a ferrite forming element, and under proper addition amount, precipitation reaction can be promoted to occur and nickel aluminum precipitation phase is formed, so that the austenitic stainless steel is reinforced, the strength of the austenitic stainless steel is further improved, meanwhile, the corrosion resistance of the stainless steel can be improved, but excessive addition can reduce the nitric acid and chloride ion corrosion resistance of the steel and the service life of the steel at the sea bottom, and therefore, the content of aluminum is controlled to be 1.0-1.5%.
Mo: the corrosion resistance of the stainless steel can be remarkably improved, and particularly in an environment containing chloride ions, molybdenum can be enriched in a passivation film close to a matrix, so that the stability of the passivation film is improved. Compared with stainless steel without molybdenum, the corrosion resistance of the molybdenum-containing stainless steel is better, but molybdenum is a ferrite forming element, and the excessive addition can influence the formation of an austenite structure in the stainless steel, so the invention limits the molybdenum content to 2.0-3.0%.
Nb: niobium is extremely stable in air at room temperature, does not react with air, can resist various corrosion, including aqua regia, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and the like, can form a dielectric oxide layer, can form a high-hardness compound niobium carbide with carbon at high temperature, and can effectively improve the mechanical properties of stainless steel. Nb is used as an alloying additive element most commonly used for stainless steel, has the effects of refining grains and inhibiting austenite recrystallization, and provides a place for phase transformation to occur in the steel. The dragging action of Nb element can hinder the movement of grain boundaries. The most outstanding feature of the steel with high Nb content is that the recrystallization termination temperature is raised with the increase of Nb content, nb is helpful for refining the metal structure of the steel in the steel rolling process, and the strength of the steel is enhanced, and the Nb content is controlled to be 0.3-1%.
Nd: is an indispensable element for improving stress corrosion cracking resistance by a synergistic effect produced by the composite addition of Ta and Nb. The carbonitride and Laves phases are refined and stabilized for a long period of time, and the grain boundaries are reinforced by the composite addition of Nd and B, whereby the stress corrosion cracking resistance is improved. However, even if Nd is added as a metal Nd, if it is precipitated as a bulk oxide or nitride, then Nd is consumed and the addition effect cannot be sufficiently obtained if the addition amount is too small, so that the amount of Nd is controlled to 0.5 to 1.5%.
Ta: tantalum is added into austenitic stainless steel, and the tantalum has extremely high corrosion resistance, and can not react with hydrochloric acid, concentrated nitric acid and aqua regia under both cold and hot conditions; tantalum is not corroded by concentrated sulfuric acid and inorganic salts at 150 ℃; at normal temperature, alkali solution, chlorine, bromine water, dilute sulfuric acid, and many other agents do not react with tantalum. The addition of tantalum not only can effectively improve the corrosion resistance of austenitic stainless steel to various corrosive substances, so that the austenitic stainless steel has high ductility and toughness, and brittle cracks are avoided; tantalum can also form solid solution and carbide with carbon, and the synergistic cooperation with niobium further improves the intergranular corrosion resistance of austenitic stainless steel; tantalum can also form solid solutions and nitrides with nitrogen, further improving the corrosion resistance and strength of austenitic stainless steel.
Y: y can play roles in strengthening grain boundaries and refining grains, and can effectively improve the nitrogen content in steel by mutual coordination with manganese element; in addition, the radius of the Y element is larger, larger lattice distortion can be generated when the Y element is dissolved into the austenitic stainless steel, so that the interface energy is reduced, the growth of crystal grains is hindered, the microhardness of the austenitic stainless steel is improved, and the high-strength corrosion-resistant ocean engineering stainless steel with high performance and green environment friendliness is obtained.
B: the boron element is added into the austenitic stainless steel, so that the grain boundary strength of the austenitic stainless steel can be remarkably improved, the high-temperature plasticity of the material is improved, for nitrogen-containing austenite with poor hot workability, a certain amount of B element is added, the reduction of area of the material at 900-1000 ℃ can be improved by 10-15%, therefore, microalloying of the boron element is generally an important means for improving the hot workability of the austenitic stainless steel, but the content of the B element is not too high, so that the plasticity and toughness of the stainless steel are seriously reduced. Thus, the content of B is controlled between 0.002-0.0028%.
P: the addition of phosphorus can effectively improve the strength and hardness of the stainless steel, but at room temperature, the plasticity and toughness of the stainless steel are rapidly reduced, and the low-temperature brittleness is generated, so that the cold embrittlement of the steel is caused. In general, phosphorus is a detrimental element in steel, and mainly precipitates a brittle compound Fe3P to increase brittleness of the steel, and particularly at low temperatures, and therefore, the content of P is limited to 0.015% or less in order to prevent excessive increase.
C: the non-raw materials are added, the austenitic region can be stabilized and enlarged in austenitic stainless steel by the preparation process or the raw materials, but the plasticity of the steel is affected by the excessive carbon content, and the corrosion resistance of the stainless steel is reduced, and in addition, elements such as manganese, nitrogen, rare earth and the like which form and stabilize an austenitic structure are added in the invention, and the influence degree of the addition of carbon on the formation of the austenitic structure is small, so that the carbon content is less than or equal to 0.02 percent for ensuring the corrosion resistance of the stainless steel.
S: sulfur, which is present in the steel in the form of FeS, can cause "hot embrittlement" of the steel, can also significantly reduce the weldability of the steel, cause high Wen Guilie, and create many pores and porosity in the metal weld joint, thereby reducing the strength of the weld joint, and studies have shown that when the sulfur content exceeds 0.06%, the corrosion resistance of the steel is significantly deteriorated. Therefore, the sulfur content of the present invention is controlled to be less than 0.015%.
The preparation method of the submarine oil and gas pipeline comprises the following steps: (1) weighing raw materials of each element;
(2) Placing iron powder into a smelting furnace, after the iron powder which is melted to 30-80% is converted into molten iron, adding molybdenum, continuing to melt until all raw materials are converted into molten iron, and marking as molten liquid A;
(3) Adding niobium, neodymium and tantalum into the molten liquid A for smelting until all components are completely melted to obtain molten liquid B;
(4) Adding silicon and manganese into the molten liquid B by an adder to fully deoxidize the melt, and standing for 3-5 minutes to obtain molten liquid C;
(5) Adding micro-carbon nitrogen-containing ferrochrome, and after the micro-carbon nitrogen-containing ferrochrome is completely dissolved, further adding aluminum to fully deoxidize to obtain a molten liquid D;
(6) Pouring the molten liquid D into a ladle after drying treatment for scouring and modifying treatment, and casting after air cooling and standing to obtain an ingot;
(7) Carrying out solution treatment on the cast ingot prepared in the step (6), and forging to obtain a forging; performing hot rolling to prepare a pipe blank;
(8) Carrying out secondary solid solution treatment on the pipe blank prepared in the step (7);
(9) Cold deformation forming is carried out on the pipe subjected to the secondary solution treatment to obtain a seamless stainless steel pipe semi-finished product;
(10) And carrying out third solid solution treatment on the seamless pipe semi-finished product, and then carrying out surface treatment, and obtaining the finished product of the submarine oil and gas transmission pipeline after the detection is qualified.
The smelting temperature in the step (2) is 1450-1500 ℃; the smelting temperature in the step (3) is 1520-1580 ℃; the smelting temperature in the step (4) is 1550-1620 ℃.
The specific process of the step (6) is that the temperature of a molten liquid D furnace is raised to 1550-1620 ℃, a casting ladle is dried at 300-500 ℃, and prefabricated yttrium particles with the size of 3-6mm are coated by a pure iron screen and then are placed at the bottom of the preheated casting ladle; pouring the molten liquid D into a casting ladle for carrying out in-ladle scouring modification treatment, standing for 6-10 minutes, and casting to obtain an ingot.
Heating the cast ingot prepared in the step (7) to 1100-1200 ℃, and forging into a forging piece; after solution treatment, hot rolling to obtain pipe blank at 1100-1200 deg.c.
The solid solution temperature in the step (8) is 1080-1150 ℃ and the solid solution time is 4-6h.
The third solid solution temperature in the step (10) is 1100-1150 ℃.
The content of nitrogen atoms in the austenitic stainless steel is far greater than that of carbon atoms, but the content of nitrogen atoms is not increased limitlessly, and the influence of the ratio of N/C on the mechanical properties of the stainless steel is researched. Although both nitrogen atoms and carbon atoms can form solid solution to strengthen austenite in the form of interstitial atoms, the action mechanisms of the two are different, the nitrogen elements can strengthen metal bonds of the steel, and the carbon elements strengthen covalent bonds among the atoms, because the electron cloud density is higher than that of carbon when the nitrogen atoms occupy interstitial positions, the nitrogen can stabilize austenite more than the carbon, the nitrogen elements can cause the increase of sliding planes and deformation twin crystals, thereby preventing dislocation movement and twin crystal expansion, greatly increasing the deformation hardening rate and strength of austenitic stainless steel, and improving the mechanical properties of low-carbon austenitic stainless steel. In addition, the nitrogen element can also form stable austenite very strongly and can enlarge the austenite phase region, so that the corrosion resistance of austenite can be further effectively improved, especially for local corrosion resistance such as intergranular corrosion, pitting corrosion, crevice corrosion, and the like.
The chromium content in the austenitic stainless steel is higher than that in the common stainless steel (12%), and in order to adapt to extremely severe environment in the ocean for a long time, the chromium content is improved to be more than 19%, so that the strength, the hardness and the wear resistance of the austenitic stainless steel are improved, and meanwhile, the plasticity and the toughness of the austenitic stainless steel are prevented from being influenced by the high chromium content.
The invention also adds tantalum, neodymium and yttrium into austenitic stainless steel, and the effect of the common addition of the three materials is obviously better than that of any one or two materials. Tantalum has extremely high corrosion resistance, and can not react with hydrochloric acid, concentrated nitric acid and aqua regia under both cold and hot conditions; tantalum is not corroded by concentrated sulfuric acid and inorganic salts at 150 ℃; at normal temperature, alkali solution, chlorine, bromine water, dilute sulfuric acid, and many other agents do not react with tantalum. The addition of tantalum not only can effectively improve the corrosion resistance of austenitic stainless steel to various corrosive substances, so that the austenitic stainless steel has high ductility and toughness, and brittle cracks are avoided; tantalum can also form solid solution and carbide with carbon, and cooperates with neodymium to further improve the intergranular corrosion resistance of austenitic stainless steel; tantalum can also form solid solutions and nitrides with nitrogen, further improving the corrosion resistance and strength of austenitic stainless steel.
The chemical property of neodymium is relatively active, and the neodymium can be darkened rapidly in the air to generate nano neodymium oxide, so that the high-temperature performance, air tightness and corrosion resistance of the alloy can be improved. The composite material can improve stress corrosion cracking resistance by improving synergistic effect with tantalum, refining carbonitride and Laves phases, stabilizing for a long time, and strengthening grain boundaries by adding neodymium and yttrium in a composite manner.
The yttrium can strengthen grain boundary and refine crystal grain, in addition, the radius of yttrium element is larger, and larger lattice distortion can be generated when the yttrium element is dissolved into austenitic stainless steel, so that the interface energy is reduced, the growth of crystal grain is prevented, the microhardness of austenitic stainless steel is improved, and the high-performance submarine oil and gas transmission pipeline is obtained.
The invention skillfully compounds tantalum, neodymium and yttrium, respectively utilizes the corrosion resistance of tantalum, and the neodymium can react with oxygen in the air at room temperature to form an oxide film, so that the air tightness and corrosion resistance of the alloy are further improved, meanwhile, yttrium has the effects of strengthening crystal boundaries and refining crystal grains, the radius of yttrium element is larger, the yttrium element is dissolved into austenitic stainless steel to generate larger lattice distortion, so that the interface energy is reduced, the growth of crystal grains is prevented, the tantalum and the neodymium can be effectively controlled to be uniformly distributed in the stainless steel and on the surface, and the three components cooperatively improve the corrosion resistance of the stainless steel, thereby improving the corrosion resistance of the austenitic stainless steel and prolonging the service life of the stainless steel at the sea bottom, and further obtaining the high-strength corrosion-resistant ocean engineering stainless steel.
The invention has the beneficial effects that:
(1) The austenitic stainless steel provided by the invention adopts Mn and Cr to replace Ni, so that the novel high-performance low-cost austenitic stainless steel is prepared, the current nickel resource shortage in China can be greatly relieved, the austenitic stainless steel has higher toughness, intergranular corrosion resistance and welding performance than those of ferrite stainless steel, and simultaneously has higher strength and corrosion capability of chloride ions in the seabed than those of common austenitic stainless steel, and can be better applied to submarine oil and gas pipelines, and the application of the austenitic stainless steel is widened.
(2) The chromium content in the austenitic stainless steel is higher than that in the common stainless steel (12%), and in order to adapt to extremely severe environment in the ocean for a long time, the chromium content is improved to be more than 19%, so that the strength, the hardness and the wear resistance of the austenitic stainless steel are improved, and meanwhile, the plasticity and the toughness of the austenitic stainless steel are prevented from being influenced by the high chromium content.
(3) According to the invention, the influence of different N/C action mechanisms on the mechanical properties of the stainless steel is studied, nitrogen elements can strengthen metal bonds of the steel, carbon elements strengthen covalent bonds among atoms, and as the electron cloud density is higher than that of carbon when nitrogen atoms occupy gap positions, nitrogen can stabilize austenite more than carbon, and nitrogen elements can cause the increase of a sliding plane and deformation twin crystals, so that dislocation movement and twin crystal expansion are prevented, the deformation hardening rate and strength of austenitic stainless steel are greatly increased, and the mechanical properties of low-carbon austenitic stainless steel are improved.
(4) The invention is characterized in that tantalum, neodymium and yttrium are added for compounding, the corrosion resistance of tantalum is utilized, neodymium can react with oxygen in air at room temperature to form an oxide film, the air tightness and corrosion resistance of the alloy are further improved, meanwhile, yttrium has the effects of strengthening crystal boundaries and refining crystal grains, the radius of yttrium element is larger, larger lattice distortion can be generated when yttrium element is dissolved into austenitic stainless steel, interface energy is reduced, crystal grain growth is prevented, tantalum and neodymium can be effectively controlled to be uniformly distributed in the stainless steel and on the surface, the corrosion resistance of the stainless steel is synergistically improved, the corrosion resistance of the austenitic stainless steel is improved, and the service life of the stainless steel at the sea bottom is prolonged, so that the high-strength corrosion-resistant ocean engineering stainless steel is obtained.
Detailed Description
The above summary of the present invention is described in further detail below in conjunction with the detailed description, but it should not be understood that the scope of the above-described subject matter of the present invention is limited to the following examples.
The submarine oil and gas transmission pipeline is made of austenitic stainless steel, and comprises the following elements in percentage by mass: 14.0-19.0% of Mn, 16.0-21.0% of Cr, 0.5-1.0% of N, less than or equal to 0.60% of Si, 1.0-1.5% of Al, 2.0-3.0% of Mo, 0.3-1.0% of Nb, 0.5-1.5% of Nd, 1.0-2.0% of Ta, 0.2-0.5% of Y, 0.002-0.0028% of B, less than or equal to 0.015% of P, less than or equal to 0.02% of C, less than or equal to 0.015% of S, less than or equal to 0.005% of O, and the balance of Fe and unavoidable impurities. The amounts of the specific elements used in each example and comparative example are shown in Table 1 below.
The preparation method of the submarine oil and gas pipeline comprises the following steps:
(1) Weighing raw materials of each element;
(2) Placing iron powder into a smelting furnace, heating to 1450 ℃, adding chromium and molybdenum after 50% of the iron powder is melted into molten iron, and continuously melting until all the raw materials are converted into molten iron, and recording as a molten liquid A;
(3) Heating the molten liquid A to 1560 ℃, adding niobium, neodymium and tantalum, heating to 1650 ℃ for smelting, and maintaining the furnace temperature at 1650 ℃ in the process until all components are completely melted to obtain molten liquid B;
(4) Reducing the furnace temperature of the molten liquid B to 1600 ℃, adding silicon and manganese by adopting a ceramic bell jar type adder, fully deoxidizing the melt, further adding aluminum for fully deoxidizing, and standing for 4 minutes to obtain molten liquid C;
(5) Adding micro-carbon nitrogen-containing ferrochrome, and after the micro-carbon nitrogen-containing ferrochrome is completely dissolved, further adding aluminum to fully deoxidize to obtain a molten liquid D;
(6) Heating the furnace temperature of the molten liquid D to 1580 ℃, drying the ladle at 400 ℃, coating the prefabricated yttrium particles with the size of 5mm by using a pure iron screen, and placing the yttrium particles at the bottom of the preheated ladle; pouring the molten liquid D into a casting ladle to carry out in-ladle scouring modification treatment, standing for 8 minutes, and casting to obtain an ingot;
(7) Heating the cast ingot prepared in the step (6) to 1150 ℃ for solution treatment, and forging to obtain a forging; performing hot rolling to obtain a pipe blank after solution treatment, wherein the rolling temperature is 1180 ℃;
(8) Carrying out secondary solution treatment on the pipe blank prepared in the step (7) for 5 hours at 1120 ℃;
(9) Cold deformation forming is carried out on the pipe subjected to the secondary solution treatment, so that the reduction of area is controlled to be between 30 percent, and a seamless stainless steel pipe semi-finished product is obtained;
(10) And placing the seamless pipe semi-finished product at 1120 ℃ for third solid solution treatment, and then carrying out surface treatment, and obtaining the finished product of the submarine oil and gas pipeline after the detection is qualified.
TABLE 1 Austenitic stainless steels of examples 1-5 and comparative examples 1-5
Test example 1
Mechanical property test: the national standard GB/T228.1-2021 section 1 of tensile test of metallic materials is adopted: room temperature test method mechanical properties of the submarine oil and gas pipelines obtained in examples 1 to 5 and comparative examples 1 to 5 were measured 5 times on average, and the results are shown in table 2.
TABLE 2 mechanical test results
As shown by the results, the submarine oil and gas transmission pipeline prepared by the invention has good mechanical properties, the content of nitrogen atoms in the austenitic stainless steel is far greater than that of carbon atoms, but the austenitic stainless steel is not increased limitlessly, and the research of the invention finds that the ratio of N/C is not less than 40 and not more than 60 has good mechanical properties. Although both nitrogen atoms and carbon atoms can form solid solution to strengthen austenite in the form of interstitial atoms, the action mechanisms of the two are different, the nitrogen elements can strengthen metal bonds of the steel, and the carbon elements strengthen covalent bonds among the atoms, because the electron cloud density is higher than that of carbon when the nitrogen atoms occupy interstitial positions, the nitrogen can stabilize austenite more than the carbon, the nitrogen elements can cause the increase of sliding planes and deformation twin crystals, thereby preventing dislocation movement and twin crystal expansion, greatly increasing the deformation hardening rate and strength of austenitic stainless steel, and improving the mechanical properties of low-carbon austenitic stainless steel. In addition, the nitrogen element can also form stable austenite very strongly and can enlarge the austenite phase region, so that the corrosion resistance of austenite can be further effectively improved, especially for local corrosion resistance such as intergranular corrosion, pitting corrosion, crevice corrosion, and the like.
The chromium content in the austenitic stainless steel is higher than that in the common stainless steel (12%), and in order to adapt to extremely severe environment in the ocean for a long time, the chromium content is improved to be more than 19%, so that the strength, the hardness and the wear resistance of the austenitic stainless steel are improved, and meanwhile, the plasticity and the toughness of the austenitic stainless steel are prevented from being influenced by the high chromium content.
Table 3 austenitic stainless steels of example 5 and comparative examples 6-11
Test example 2
Corrosion resistance test: the submarine oil and gas pipelines of example 5 and comparative examples 6 to 11 were placed in the following corrosive solutions, respectively:
a. nitric acid solution with the mass fraction of 50%; b. hydrochloric acid solution with mass fraction of 30%; c. bromine water with mass fraction of 2.5%; the corrosion degree of each corrosive solution on each seamless stainless steel pipe was measured by corrosion at normal temperature and 100 ℃ for 72 hours, and the results are shown in table 4.
TABLE 4 test of corrosion resistance
From the test results, the submarine oil and gas transmission pipeline prepared by the method has good corrosion resistance, and the corrosion resistance effect of the compound of tantalum, neodymium and yttrium is obviously better than that of any one or two of the other compounds, so that the service life of the pipeline on the seabed can be prolonged. The reason is that tantalum, neodymium and yttrium are added into austenitic stainless steel, wherein tantalum has extremely high corrosion resistance, and can not react with hydrochloric acid, concentrated nitric acid and aqua regia under both cold and hot conditions; tantalum is not corroded by concentrated sulfuric acid and inorganic salts at 150 ℃; at normal temperature, alkali solution, chlorine, bromine water, dilute sulfuric acid, and many other agents do not react with tantalum. The addition of tantalum not only can effectively improve the corrosion resistance of austenitic stainless steel to various corrosive substances, so that the austenitic stainless steel has high ductility and toughness, and brittle cracks are avoided; tantalum can also form solid solution and carbide with carbon, and cooperates with neodymium to further improve the intergranular corrosion resistance of austenitic stainless steel; tantalum can also form solid solutions and nitrides with nitrogen, further improving the corrosion resistance and strength of austenitic stainless steel.
The chemical property of neodymium is relatively active, and the neodymium can be darkened rapidly in the air to generate nano neodymium oxide, so that the high-temperature performance, air tightness and corrosion resistance of the alloy can be improved. The composite material can improve stress corrosion cracking resistance by improving synergistic effect with tantalum, refining carbonitride and Laves phases, stabilizing for a long time, and strengthening grain boundaries by adding neodymium and yttrium in a composite manner.
The yttrium can strengthen grain boundary and refine crystal grain, in addition, the radius of yttrium element is larger, and larger lattice distortion can be generated when the yttrium element is dissolved into austenitic stainless steel, so that the interface energy is reduced, the growth of crystal grain is prevented, the microhardness of austenitic stainless steel is improved, and the high-performance submarine oil and gas transmission pipeline is obtained.
The invention skillfully compounds tantalum, neodymium and yttrium, respectively utilizes the corrosion resistance of tantalum, and the neodymium can react with oxygen in the air at room temperature to form an oxide film, so that the air tightness and corrosion resistance of the alloy are further improved, meanwhile, yttrium has the effects of strengthening crystal boundaries and refining crystal grains, the radius of yttrium element is larger, the yttrium element is dissolved into austenitic stainless steel to generate larger lattice distortion, so that the interface energy is reduced, the growth of crystal grains is prevented, the tantalum and the neodymium can be effectively controlled to be uniformly distributed in the stainless steel and on the surface, and the three components cooperatively improve the corrosion resistance of the stainless steel, thereby improving the corrosion resistance of the austenitic stainless steel and prolonging the service life of the stainless steel at the sea bottom, and further obtaining the high-strength corrosion-resistant ocean engineering stainless steel.
Claims (7)
1. The submarine oil and gas transmission pipeline is made of austenitic stainless steel and is characterized by comprising the following element components in percentage by mass: 14.0-19.0% of Mn, 16.0-21.0% of Cr, 0.5-1.0% of N, less than or equal to 0.60% of Si, 1.0-1.5% of Al, 2.0-3.0% of Mo, 0.3-1.0% of Nb, 0.5-1.5% of Nd, 1.0-2.0% of Ta, 0.2-0.5% of Y, 0.002-0.0028% of B, less than or equal to 0.015% of P, less than or equal to 0.02% of C, less than or equal to 0.015% of S, less than or equal to 0.005% of O, and the balance of Fe and unavoidable impurities.
The ratio of N/C is 40-60;
the preparation method of the submarine oil and gas pipeline comprises the following steps:
(1) Weighing raw materials of each element;
(2) Placing iron powder into a smelting furnace, after the iron powder which is melted to 30-80% is converted into molten iron, adding molybdenum, continuing to melt until all raw materials are converted into molten iron, and marking as molten liquid A;
(3) Adding niobium, neodymium and tantalum into the molten liquid A for smelting until all components are completely melted to obtain molten liquid B;
(4) Adding silicon and manganese into the molten liquid B by an adder to fully deoxidize the melt, and standing for 3-5 minutes to obtain molten liquid C;
(5) Adding micro-carbon nitrogen-containing ferrochrome, and adding aluminum for full deoxidation after the micro-carbon nitrogen-containing ferrochrome is completely dissolved to obtain a molten liquid D;
(6) Pouring the molten liquid D into a ladle after drying treatment for scouring and modifying treatment, and casting after air cooling and standing to obtain an ingot;
(7) Carrying out solution treatment on the cast ingot prepared in the step (6), and forging to obtain a forging; performing hot rolling to prepare a pipe blank;
(8) Carrying out secondary solid solution treatment on the pipe blank prepared in the step (7);
(9) Cold deformation forming is carried out on the pipe subjected to the secondary solution treatment to obtain a seamless stainless steel pipe semi-finished product;
(10) Carrying out third solid solution treatment on the seamless stainless steel tube semi-finished product, and then carrying out surface treatment, and obtaining the finished product of the submarine oil and gas transmission pipeline after the detection is qualified;
the solid solution temperature in the step (8) is 1080-1150 ℃ and the solid solution time is 4-6h.
2. The submarine oil and gas pipeline according to claim 1, wherein the submarine oil and gas pipeline is made of austenitic stainless steel, and is characterized by comprising the following element components in percentage by mass: 15.0-18.0% Mn, 18.0-20.0% Cr, 0.6-0.9% N, 0.2-0.5% Si, 1.1-1.4% Al, 2.2-2.8% Mo, 0.5-1.0% Nb, 0.8-1.2% Nd, 1.2-1.8% Ta, 0.25-0.45% Y, 0.0022-0.0027% B, 0.008-0.012% P, 0.01-0.018% C, 0.008-0.014% S, 0.001-0.004% O, and the balance Fe and unavoidable impurities.
3. A method of producing a submarine oil and gas pipeline according to claim 1 or 2, comprising the steps of:
(1) Weighing raw materials of each element;
(2) Placing iron powder into a smelting furnace, after the iron powder which is melted to 30-80% is converted into molten iron, adding molybdenum, continuing to melt until all raw materials are converted into molten iron, and marking as molten liquid A;
(3) Adding niobium, neodymium and tantalum into the molten liquid A for smelting until all components are completely melted to obtain molten liquid B;
(4) Adding silicon and manganese into the molten liquid B by an adder to fully deoxidize the melt, and standing for 3-5 minutes to obtain molten liquid C;
(5) Adding micro-carbon nitrogen-containing ferrochrome, and adding aluminum for full deoxidation after the micro-carbon nitrogen-containing ferrochrome is completely dissolved to obtain a molten liquid D;
(6) Pouring the molten liquid D into a ladle after drying treatment for scouring and modifying treatment, and casting after air cooling and standing to obtain an ingot;
(7) Carrying out solution treatment on the cast ingot prepared in the step (6), and forging to obtain a forging; performing hot rolling to prepare a pipe blank;
(8) Carrying out secondary solid solution treatment on the pipe blank prepared in the step (7);
(9) Cold deformation forming is carried out on the pipe subjected to the secondary solution treatment to obtain a seamless stainless steel pipe semi-finished product;
(10) Carrying out third solid solution treatment on the seamless stainless steel tube semi-finished product, and then carrying out surface treatment, and obtaining the finished product of the submarine oil and gas transmission pipeline after the detection is qualified;
the solid solution temperature in the step (8) is 1080-1150 ℃ and the solid solution time is 4-6h.
4. The method for producing a submarine oil and gas pipeline according to claim 3, wherein the melting temperature in the step (2) is 1450-1500 ℃; the smelting temperature in the step (3) is 1520-1580 ℃; the smelting temperature in the step (4) is 1550-1620 ℃.
5. The method for preparing the submarine oil and gas pipeline according to claim 3, wherein the specific process of the step (6) is that the temperature of a molten liquid D furnace is raised to 1550-1620 ℃, a casting ladle is dried at 300-500 ℃, and prefabricated yttrium particles with the size of 3-6mm are coated by a pure iron screen and then are placed at the bottom of the preheated casting ladle; pouring the molten liquid D into a casting ladle for carrying out in-ladle scouring modification treatment, standing for 6-10 minutes, and casting to obtain an ingot.
6. The method for preparing the submarine oil and gas pipeline according to claim 3, wherein the cast ingot prepared in the step (7) is heated to 1100-1200 ℃ and is forged into a forging piece; after solution treatment, hot rolling to obtain pipe blank at 1100-1200 deg.c.
7. A method for producing a submarine oil and gas pipeline according to claim 3, wherein the third solid solution temperature in step (10) is 1100 to 1150 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310114232.9A CN115961216B (en) | 2023-02-15 | 2023-02-15 | Submarine oil and gas transmission pipeline and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310114232.9A CN115961216B (en) | 2023-02-15 | 2023-02-15 | Submarine oil and gas transmission pipeline and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115961216A CN115961216A (en) | 2023-04-14 |
| CN115961216B true CN115961216B (en) | 2023-08-04 |
Family
ID=87353110
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310114232.9A Active CN115961216B (en) | 2023-02-15 | 2023-02-15 | Submarine oil and gas transmission pipeline and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115961216B (en) |
Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101250674A (en) * | 2008-04-11 | 2008-08-27 | 江苏大学 | Mid nitrogen high manganese austenitic stainless steel |
| CN102199738A (en) * | 2010-03-23 | 2011-09-28 | 重庆仪表材料研究所 | Low carbon, nickel-saving, high-strength, high-toughness, corrosion-resistant and nonmagnetic austenite stainless steel |
| CN102888566A (en) * | 2012-11-06 | 2013-01-23 | 重庆材料研究院 | Medical high-nitrogen nickel-free austenitic stainless steel material and production method thereof |
| CN103374685A (en) * | 2012-04-23 | 2013-10-30 | 钢铁研究总院 | Stainless steel material and manufacturing method thereof |
| CN104878316A (en) * | 2014-02-27 | 2015-09-02 | 南京理工大学 | High-strength high-toughness high-nitrogen austenitic stainless steel |
| CN105177257A (en) * | 2015-09-29 | 2015-12-23 | 东北大学 | High-nitrogen nickel-free austenitic stainless steel intergranular-corrosion-prevention processing technology |
| CN106244945A (en) * | 2016-08-26 | 2016-12-21 | 浙江隆达不锈钢有限公司 | Corrosion-and high-temp-resistant gapless stainless steel tube and the preparation method of this gapless stainless steel tube |
| JP2017031483A (en) * | 2015-08-05 | 2017-02-09 | 新日鐵住金株式会社 | HIGH Mn STEEL MATERIAL FOR HIGH PRESSURE HYDROGEN GAS AND MANUFACTURING METHOD THEREFOR, PIPE, CONTAINER, VALVE AND JOINT CONSISTING OF THE STEEL MATERIAL |
| CN106574351A (en) * | 2014-08-21 | 2017-04-19 | 奥托库姆普联合股份公司 | High strength austenitic stainless steel and production method thereof |
| KR20180076081A (en) * | 2016-12-27 | 2018-07-05 | 충남대학교산학협력단 | Heat-resistant steel having high mechanical property and workability |
| CN108559918A (en) * | 2018-04-18 | 2018-09-21 | 江苏理工学院 | A kind of nickel-less austenitic stainless steel alloy and its processing technology |
| CH716938A2 (en) * | 2019-12-13 | 2021-06-15 | Swatch Group Res & Dev Ltd | Paramagnetic hard stainless steel and its manufacturing process. |
| CN114032461A (en) * | 2021-11-04 | 2022-02-11 | 华北理工大学 | High-nitrogen steel with high strength, low yield ratio and high corrosion resistance for marine engineering and preparation method thereof |
| EP4014950A1 (en) * | 2020-12-18 | 2022-06-22 | Deutsche Edelstahlwerke Specialty Steel GmbH & Co. KG | Steel with an austenitic structure and use of such a steel for applications in the oral cavity of a human or animal |
| CN115522130A (en) * | 2021-10-08 | 2022-12-27 | 赵洪运 | High-strength corrosion-resistant ocean engineering stainless steel and preparation method thereof |
| CN115627428A (en) * | 2022-10-21 | 2023-01-20 | 山东烟炉节能科技有限公司 | Seawater desalination engineering pipeline and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5526809B2 (en) * | 2009-04-27 | 2014-06-18 | 大同特殊鋼株式会社 | High corrosion resistance, high strength, non-magnetic stainless steel and high corrosion resistance, high strength, non magnetic stainless steel products and methods for producing the same |
-
2023
- 2023-02-15 CN CN202310114232.9A patent/CN115961216B/en active Active
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101250674A (en) * | 2008-04-11 | 2008-08-27 | 江苏大学 | Mid nitrogen high manganese austenitic stainless steel |
| CN102199738A (en) * | 2010-03-23 | 2011-09-28 | 重庆仪表材料研究所 | Low carbon, nickel-saving, high-strength, high-toughness, corrosion-resistant and nonmagnetic austenite stainless steel |
| CN103374685A (en) * | 2012-04-23 | 2013-10-30 | 钢铁研究总院 | Stainless steel material and manufacturing method thereof |
| CN102888566A (en) * | 2012-11-06 | 2013-01-23 | 重庆材料研究院 | Medical high-nitrogen nickel-free austenitic stainless steel material and production method thereof |
| CN104878316A (en) * | 2014-02-27 | 2015-09-02 | 南京理工大学 | High-strength high-toughness high-nitrogen austenitic stainless steel |
| CN106574351A (en) * | 2014-08-21 | 2017-04-19 | 奥托库姆普联合股份公司 | High strength austenitic stainless steel and production method thereof |
| JP2017031483A (en) * | 2015-08-05 | 2017-02-09 | 新日鐵住金株式会社 | HIGH Mn STEEL MATERIAL FOR HIGH PRESSURE HYDROGEN GAS AND MANUFACTURING METHOD THEREFOR, PIPE, CONTAINER, VALVE AND JOINT CONSISTING OF THE STEEL MATERIAL |
| CN105177257A (en) * | 2015-09-29 | 2015-12-23 | 东北大学 | High-nitrogen nickel-free austenitic stainless steel intergranular-corrosion-prevention processing technology |
| CN106244945A (en) * | 2016-08-26 | 2016-12-21 | 浙江隆达不锈钢有限公司 | Corrosion-and high-temp-resistant gapless stainless steel tube and the preparation method of this gapless stainless steel tube |
| KR20180076081A (en) * | 2016-12-27 | 2018-07-05 | 충남대학교산학협력단 | Heat-resistant steel having high mechanical property and workability |
| CN108559918A (en) * | 2018-04-18 | 2018-09-21 | 江苏理工学院 | A kind of nickel-less austenitic stainless steel alloy and its processing technology |
| CH716938A2 (en) * | 2019-12-13 | 2021-06-15 | Swatch Group Res & Dev Ltd | Paramagnetic hard stainless steel and its manufacturing process. |
| EP4014950A1 (en) * | 2020-12-18 | 2022-06-22 | Deutsche Edelstahlwerke Specialty Steel GmbH & Co. KG | Steel with an austenitic structure and use of such a steel for applications in the oral cavity of a human or animal |
| CN115522130A (en) * | 2021-10-08 | 2022-12-27 | 赵洪运 | High-strength corrosion-resistant ocean engineering stainless steel and preparation method thereof |
| CN114032461A (en) * | 2021-11-04 | 2022-02-11 | 华北理工大学 | High-nitrogen steel with high strength, low yield ratio and high corrosion resistance for marine engineering and preparation method thereof |
| CN115627428A (en) * | 2022-10-21 | 2023-01-20 | 山东烟炉节能科技有限公司 | Seawater desalination engineering pipeline and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115961216A (en) | 2023-04-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101828856B1 (en) | A steel rebar and a production method thereof | |
| US5298093A (en) | Duplex stainless steel having improved strength and corrosion resistance | |
| CN112226693A (en) | Low-alloy high-strength corrosion-resistant steel bar and preparation method thereof | |
| CN110724872A (en) | High manganese austenitic steel with ultralow-temperature impact toughness and manufacturing method of hot rolled plate thereof | |
| WO2020135437A1 (en) | Steel resistant to seawater corrosion and manufacturing method therefor | |
| WO2023165617A1 (en) | High-strength and high-toughness steel with long service life and wall thickness of ≥ 600 mm for valve body of subsea christmas tree, and heat treatment method and production method therefor | |
| CN107717257B (en) | Flux-cored wire matched with ultra-supercritical heat-resistant steel and preparation method thereof | |
| CN110066957A (en) | Corrosion-resistant super austenitic stainless steel of modified and preparation method thereof | |
| CN113737090A (en) | High-strength and high-toughness alloy structural steel and preparation method thereof | |
| CN111074155B (en) | High-strength hydrogen sulfide corrosion-resistant oil well pipe steel and preparation method thereof | |
| WO2023165611A1 (en) | Steel for high-toughness corrosion-resistant christmas tree valve bodies smelted at high scrap ratio, and heat treatment method and production method therefor | |
| CN104611640A (en) | High boron iron-based erosion-corrosion resistant alloy and preparation method thereof | |
| CN115961216B (en) | Submarine oil and gas transmission pipeline and preparation method thereof | |
| CN114875302B (en) | Low-alloy steel and preparation method and application thereof | |
| KR101089714B1 (en) | C+N austenitic stainless steel with high strength and corrosion resistance having tungsten and fabrication method thereof | |
| WO2023240850A1 (en) | 960 mpa grade ultrahigh-strength steel plate with marine fouling resistance and manufacturing method therefor | |
| CN115522130A (en) | High-strength corrosion-resistant ocean engineering stainless steel and preparation method thereof | |
| CN111549297B (en) | Preparation method of high-strength anti-seismic weather-resistant fire-resistant low-temperature-resistant easily-welded H-shaped steel | |
| CN113234997A (en) | Novel manganese nitrogen chromium heat-resistant steel and manufacturing method thereof | |
| CN112410675A (en) | Rare earth double-phase corrosion-resistant cast stainless steel and manufacturing method thereof | |
| CN108642386B (en) | Seawater corrosion resistant high-strength steel | |
| CN112375957B (en) | Nickel-iron-based corrosion-resistant alloy and preparation method thereof | |
| WO2024088380A1 (en) | High-strength corrosion-resistant steel for photovoltaic pile foundation and manufacturing method therefor | |
| CN113564459B (en) | High-performance steel plate for resisting ocean tidal range zone corrosion and production method thereof | |
| CN113201697B (en) | High-temperature concentrated sulfuric acid corrosion resistant austenitic stainless steel with excellent hot-working performance and hot-piercing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |