CN-122013068-A - Carbon dioxide and hydrogen sulfide corrosion resistant 5Cr seamless steel pipe and manufacturing method thereof

CN122013068ACN 122013068 ACN122013068 ACN 122013068ACN-122013068-A

Abstract

The invention discloses a 5Cr seamless steel pipe resistant to corrosion of carbon dioxide and hydrogen sulfide and a manufacturing method thereof, and relates to the technical field of seamless steel pipes. Through the precise alloy composition design, the specific steelmaking, rolling and heat treatment processes are combined, so that grains can be effectively refined, and stable tempered sorbite tissues can be formed. The 5Cr seamless steel pipe prepared by the method not only has the performance of resisting corrosion of carbon dioxide and hydrogen sulfide, but also can meet the requirements on mechanical properties such as strength and the like, so that the 5Cr seamless steel pipe can safely and stably operate in the severe corrosion environment of an oil-gas field, the service life of the 5Cr seamless steel pipe is prolonged, and the cost is reduced.

Inventors

SUN JING
XU TIAN
Sui Lutong
ZHANG XINGLI
MA JISHUN
YUAN SHUAISHUAI
WANG TAO
WANG HONGBING

Assignees

山东墨龙石油机械股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. A5 Cr seamless steel pipe resistant to corrosion of carbon dioxide and hydrogen sulfide is characterized in that: comprises the following components ：C：0.08～0.15%,Si：0.17～0.35%,Mn：0.50～1.00%,P≤0.015%,S≤0.008%,Cu≤0.20%,Ni：0.10～0.20%,Cr：4.80～5.80%,Mo：0.30～0.70%,V：0.01～0.03%,Nb≤0.01%,Ti≤0.015%,B≤0.001%,Al：0.010～0.030%,8≤Cr/Mo≤16, in percentage by weight, and the balance of Fe and unavoidable impurities.
2. The 5Cr seamless steel pipe resistant to corrosion by carbon dioxide and hydrogen sulfide according to claim 1, wherein the technical indexes achieved by the 5Cr seamless steel pipe resistant to corrosion by carbon dioxide and hydrogen sulfide are as follows: the yield strength is 552-758 mpa; The tensile strength is 689-889 mpa; the elongation is more than or equal to 15 percent; the transverse full-size Charpy impact energy at 0 ℃ is more than or equal to 60J, or the longitudinal full-size Charpy impact energy is more than or equal to 80J; the hardness is more than or equal to 18.0HRC.
3. The seamless steel pipe of claim 1, wherein the seamless steel pipe is rated by the sulfide stress corrosion cracking test of: The test was carried out using solutions A and A of NACE TM0177 standard, using a 6.35mm diameter corrosion bar specimen for sulfide stress corrosion cracking with a 720 hour test period, a constant tensile stress of 469.0MPa applied by the test, which is 85% of the minimum yield strength of the corrosion bar specimen, and the test verifies that the specimen does not experience environmental cracking and hydrogen induced cracking during the 720 hour test period.
4. The seamless steel pipe of claim 1, wherein the seamless steel pipe is rated by the sulfide stress corrosion cracking test of: The test was carried out using solutions A and A of NACE TM0177 standard, using a test specimen of corrosion bar having a diameter of 3.81mm for sulfide stress corrosion cracking, a test period of 720 hours, a constant tensile stress of 419.5MPa was applied to the test specimen, which was 76% of the minimum yield strength of the test specimen, and it was verified by the test that the test specimen did not undergo environmental fracture and hydrogen induced cracking during the test period of 720 hours.
5. The method for producing a seamless steel pipe of 5Cr resistant to corrosion by carbon dioxide and hydrogen sulfide according to claim 1, wherein the seamless steel pipe is evaluated by a carbon dioxide corrosion test: The test is carried out by adopting the ASTM G111 standard, the test solution adopts NACE TM0177 standard A solution, the test temperature is 90 ℃, the carbon dioxide partial pressure is 0.6MPa, the stirring rate is 2m/s, the test period is 72 hours, and the average corrosion rate of the seamless steel pipe in a carbon dioxide environment is less than or equal to 0.076 mm/year after the test is finished.
6. A method for manufacturing a 5Cr seamless steel pipe resistant to corrosion of carbon dioxide and hydrogen sulfide is characterized by comprising the following steps: The method for smelting the 5Cr seamless steel pipe resistant to corrosion of carbon dioxide and hydrogen sulfide according to the claim 1 comprises the following steps: Steelmaking process: s100, smelting in a converter, wherein a double slag method process is used, the early stage is rapidly dephosphorized at 1400-1450 ℃, and the later stage is reinforced for decarburization at 1600-1660 ℃; S110, controlling slag discharging amount by adopting a slag blocking and tapping technology in the tapping process, and adding synthetic refining slag or deoxidizing agent to perform pre-refining; s120, refining molten steel in an LF furnace, electrifying, heating and deslagging, adding a deoxidizer for diffusion deoxidization to produce high-alkalinity white slag, performing deep desulfurization and inclusion adsorption, performing temperature measurement and sampling in the process, and detecting molten steel components; S130, the molten steel enters a VD furnace to be subjected to vacuum treatment, calcium treatment operation is carried out after the molten steel is broken, a silicon-calcium wire or a pure calcium wire is fed during the calcium treatment to carry out denaturation treatment on inclusions, and then soft argon blowing stirring is carried out; S140, after soft blowing is finished, detecting the gas content and the temperature to ensure that the quality of molten steel meets the standard; s150, continuous casting is carried out by using molten steel conforming to the quality so as to obtain a continuous casting round billet; and (3) rolling: s200, feeding the continuous casting round billet into an annular furnace for heating, wherein the heating temperature is 1230-1260 ℃; s210, perforating after the continuous casting round billet is discharged from the annular furnace; S220, rolling the continuous casting round billet at 990-1070 ℃, penetrating the mandrel into the blank pipe in a matched manner during rolling, and starting an intermediate frequency heating furnace to control the final rolling temperature at 820-880 ℃; s230, air cooling the rolled capillary tube to room temperature through a cooling bed, and sawing; And (3) a heat treatment procedure: S300, carrying out austenitizing heating on the rolled and sawed steel pipe in a stepping furnace, wherein the heating temperature is 870-930 ℃, and preserving heat for 15-100 minutes; s310, quenching and cooling by adopting steel pipe rotary inner water spray and outer water spray cooling on a quenching machine tool, and cooling to room temperature; S320, conveying the steel pipe into a tempering furnace for tempering, wherein the tempering heating temperature is 620-690 ℃, and preserving heat for 30-120 minutes; s330, carrying out hot straightening on the steel pipe at 480-650 ℃ after the steel pipe is discharged from the furnace; S340, naturally cooling to room temperature in the air, and then performing flaw detection by using an ultrasonic flaw detector.
7. The method for producing a seamless steel pipe resistant to corrosion by carbon dioxide and hydrogen sulfide according to claim 6, wherein in step S120, the target basicity R of the high basicity white slag is controlled to be 2.6 to 3.0.
8. The method for producing a seamless steel pipe of 5Cr according to claim 7, wherein in step S130, the soft blowing time is 8 minutes or longer during the soft blowing and stirring.
9. The method of manufacturing a seamless steel pipe of 5Cr resistant to corrosion by carbon dioxide and hydrogen sulfide according to claim 8, wherein in step S210, the piercing temperature is 1090 ℃ to 1120 ℃, the piercing tool comprises a cobalt-based plug and a high alloy guide plate, and a hollow capillary is obtained after piercing.
10. The method for producing a 5Cr seamless steel pipe resistant to corrosion by carbon dioxide and hydrogen sulfide according to claim 9, wherein in step S220, a core rod lubricant comprising borax is added between said core rod and the inner wall of the capillary, and 1000g of borax is blown onto the inner wall of the capillary.

Description

Carbon dioxide and hydrogen sulfide corrosion resistant 5Cr seamless steel pipe and manufacturing method thereof Technical Field The invention relates to the technical field of seamless steel pipes, in particular to a 5Cr seamless steel pipe resistant to corrosion of carbon dioxide and hydrogen sulfide and a manufacturing method thereof. Background The exploitation environment of petroleum and natural gas is increasingly complex, and exploitation environment containing carbon dioxide and hydrogen sulfide is often encountered in the oil and gas exploitation process. The high-concentration carbon dioxide reacts with water to generate carbonic acid, which can generate strong corrosion to metal pipelines, so that the wall thickness of the pipelines is reduced, the strength is reduced, even safety accidents such as leakage are caused, and the continuity and safety of oil and gas exploitation are seriously influenced. Hydrogen sulfide not only has strong corrosiveness, but also can react with steel to generate ferrous sulfide, and simultaneously causes more serious damage forms such as hydrogen induced cracking, sulfide stress corrosion cracking and the like. Particularly in an acidic environment containing hydrogen sulfide, hydrogen atoms can penetrate into the steel and accumulate in the stress concentration area to form hydrogen gas, so that the steel is embrittled and even cracked. Such damage is often sudden and catastrophic, and constitutes a significant threat to the safe production of oil and gas fields. In petroleum and natural gas exploitation, the ability of steel pipes to resist carbon dioxide and hydrogen sulfide corrosion is a core technical condition for ensuring safe exploitation, compliance operation, continuous profitability and environmental friendliness. The corrosion rate of the traditional carbon steel and low alloy steel in the environment where carbon dioxide and hydrogen sulfide coexist is increased sharply, the problems of insufficient corrosion resistance, short service life and the like exist, and the frequent replacement of the pipeline not only increases the operation cost, but also causes huge economic loss due to the shutdown and maintenance. The existing partial corrosion resistant alloy (such as 13Cr stainless steel) has better corrosion resistance, but has high cost and limited processability, and is difficult to be applied on a large scale. The common 5Cr steel has the defects in component design and process control, so that grains are coarse and have uneven microstructure, the corrosion resistance and mechanical properties of the common 5Cr steel are difficult to be compatible, the long-term service requirements of severe environments such as deep wells, ultra-deep wells and the like are difficult to be met, and the service life of the common 5Cr steel is greatly shortened. Therefore, a 5Cr seamless steel pipe which has excellent carbon dioxide and hydrogen sulfide corrosion resistance, good mechanical property and controllable cost is developed, and the manufacturing method thereof is provided, so that the method has important practical significance and wide application prospect for guaranteeing safe and efficient production of oil and gas fields and reducing the cost of the whole life cycle. Disclosure of Invention Aiming at the defects in the prior art, the technical problem to be solved by the invention is to provide the 5Cr seamless steel tube resistant to corrosion of carbon dioxide and hydrogen sulfide and the manufacturing method thereof, and the prepared seamless steel tube has excellent resistance to corrosion of carbon dioxide and hydrogen sulfide by controlling the proportion of each component and combining a specific process, and meets the requirements of the seamless steel tube on mechanical properties such as strength, toughness and the like, so that the seamless steel tube has the advantages of long service life and low cost. In order to solve the technical problems, the invention adopts the following technical scheme: A5 Cr seamless steel pipe resistant to corrosion of carbon dioxide and hydrogen sulfide comprises the following components ：C：0.08～0.15%,Si：0.17～0.35%,Mn：0.50～1.00%,P≤0.015%,S≤0.008%,Cu≤0.20%,Ni：0.10～0.20%,Cr：4.80～5.80%,Mo：0.30～0.70%,V：0.01～0.03%,Nb≤0.01%,Ti≤0.015%,B≤0.001%,Al：0.010～0.030%,8≤Cr/Mo≤16, in percentage by weight, and the balance of Fe and unavoidable impurities. Preferably, the technical indexes of the 5Cr seamless steel pipe resisting the corrosion of carbon dioxide and hydrogen sulfide are as follows: the yield strength is 552-758 mpa; The tensile strength is 689-889 mpa; the elongation is more than or equal to 15 percent; the transverse full-size Charpy impact energy at 0 ℃ is more than or equal to 60J, or the longitudinal full-size Charpy impact energy is more than or equal to 80J; Hardness is more than or equal to 18.0HRC; Preferably, the seamless steel pipe is evaluated by the sulfide stress corrosion cracking test: The test wa