阅读说明：本技术 深海天然气管线测试压力帽及对接毂用f65m特大壁厚高强度锻件 (Deep sea natural gas pipeline test pressure cap and F65M super-large wall thickness high-strength forging for butt joint hub ) 是由 葛辉 周勇 于 2021-07-19 设计创作，主要内容包括：本发明公开了一种深海天然气管线测试压力帽及对接毂用F65M特大壁厚高强度锻件的生产工艺,步骤如下：下料；锻造；正火、淬火、回火处理；进行无损探伤及机械加工。本发明的优点在于：通过上述生产工艺生产的F65特大壁厚快速连接器锻件,在壁厚超过100mm后还具备非常优良的可焊性和低温性能,在保证冲击性能的同时,锻件中心的屈服强度大于450Mpa,解决了在低温冲击出现单个最低要求不满足的问题。(The invention discloses a production process of a deep-sea natural gas pipeline test pressure cap and an F65M extra-large wall thickness high-strength forging for a butt joint hub, which comprises the following steps: blanking; forging; normalizing, quenching and tempering; and carrying out nondestructive inspection and machining. The invention has the advantages that: the F65 rapid connector forging with the extra-large wall thickness produced by the production process has excellent weldability and low-temperature performance after the wall thickness exceeds 100mm, ensures the impact performance, has the yield strength of the center of the forging larger than 450MPa, and solves the problem that the single minimum requirement is not satisfied during low-temperature impact.)

1. The production process of the F65M super-large wall thickness high-strength forging for the deep-sea natural gas pipeline test pressure cap and the butt joint hub is characterized in that: the method comprises the following steps:

a. blanking: taking a steel billet with the chemical components by weight percentage of less than or equal to 0.12 percent of C, 0.2 to 0.45 percent of Si, 1.1 to 1.4 percent of Mn, less than or equal to 0.01 percent of S, less than or equal to 0.015 percent of P, 0.1 to 0.5 percent of Cr, 0.5 to 0.99 percent of Ni, 0.15 to 0.5 percent of Mo, 0.02 to 0.055 percent of Al, less than or equal to 0.02 percent of Nb, less than or equal to 0.06 percent of V, less than or equal to 0.005 percent of Ca, less than or equal to 0.025 percent of Ti, less than or equal to 0.015 percent of Sn, less than or equal to 0.02 percent of Sb, less than or equal to 0.02 percent of As, less than or equal to 0.01 percent of Pb, less than or equal to 0.01 percent of Bi, less than or equal to 0.0005 percent of B, less than or equal to 0.3 percent of Cu, less than or equal to 2ppm of H, less than or equal to 0.012 percent of N, less than or equal to 25ppm of O and 0.4 to 0.45 percent of Cev As a raw material;

b. forging: placing the steel billet into a forging furnace, firstly heating the steel billet to 800 ℃ and preserving heat for more than or equal to 2 hours, then heating the steel billet at 800 ℃ to 1180 +/-20 ℃ and preserving heat for more than or equal to 3.5 hours, then forging the steel billet, forging the steel billet into a forged piece with an inner hole, controlling the initial forging temperature to be 1180 +/-20 ℃ and the final forging temperature to be 850 +/-20 ℃ in the forging process, controlling the drawing ratio to be more than 3:1, the upsetting ratio to be more than 2:1 and the total forging ratio to be more than 6:1 in the forging process, and cooling the forged piece to room temperature after the forging is finished;

c. normalizing, quenching and tempering: firstly, heating the forging to 580 ℃ and preserving heat for 1.5h, then heating the forging at 580 ℃ to 960 +/-10 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 hour/inch (inch is the maximum wall thickness dimension of the forging), and then air-cooling to room temperature; heating the forging to 580 ℃ and preserving heat for 1.5h, then heating the 580 ℃ forging to 920 +/-10 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 hour/inch (inch is the maximum wall thickness of the forging), then transferring the forging to cooling water within 90 seconds for water quenching to room temperature, and continuously spraying the cooling water into an inner hole on the forging by using a high-pressure fluid pump in the water quenching process; heating the forging to 200 ℃ and preserving heat for 1h, then heating the forging at 200 ℃ to 510 ℃ and preserving heat for 1.5h, finally heating the forging at 510 ℃ to 550 +/-8 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 h/inch (inch is the maximum wall thickness of the forging), and then air-cooling to room temperature;

d. and carrying out nondestructive inspection and machining.

2. The deep sea natural gas pipeline test pressure cap and butt joint hub F65M extra large wall thickness high strength forging of claim 1, wherein: in the discharging step, an EF + LF + VD bottom pouring type vacuum protection pouring smelting process is adopted.

3. The deep sea natural gas pipeline test pressure cap and butt joint hub F65M extra large wall thickness high strength forging of claim 1, wherein: the heating rate during forging is controlled to be not higher than 125 ℃/h.

4. The deep sea natural gas pipeline test pressure cap and butt joint hub F65M extra large wall thickness high strength forging of claim 1, wherein: the heating rate in the normalizing, quenching and tempering processes is controlled to be not higher than 150 ℃/h.

Technical Field

The invention relates to the application field of high-performance forging material for deep sea high-end equipment, in particular to a deep sea natural gas pipeline testing pressure cap and an F65M extra-large wall thickness high-strength forging for a butt joint hub.

Background

China faces many challenges in offshore oil engineering, for example, China focuses on manufacturing and assembling in EPC, and engineering design and equipment procurement need to be enhanced; the ocean engineering has high risk and is safe and environment-friendly; in recent years, the international oil price is greatly reduced, so that marine oil development projects at home and abroad are greatly compressed and delayed, and the price advantage is lost due to the change of the vigilant exchange rate. Deep water oil and gas development in China faces severe marine environments and terrain conditions such as internal waves and typhoons, and seabed terrain and engineering address conditions are complex; on the other hand, the oil and gas reservoir characteristics in China are complex, the difference between the oil and gas reservoir characteristics and the western aspect in exploration, development technology and the like is still large, and the deepwater emergency rescue capability is still in a blank state. Therefore, the technical development mode of marine oil engineering is innovated by combining independent innovation and international cooperation development. All of which require high performance materials as a basis.

Deep sea quick connector forging material generally adopts American standard ASTM A182F 22 or ordinary F65 class material forging of small wall thickness. But the weldability of ASTM A182F 22 grade is poor, and post-welding heat treatment is required after welding, which causes difficulty and greatly increases the cost for field construction; and the design of the forging made of the common F65-grade material with small wall thickness causes the complex structure of the whole equipment, the reduction of safety coefficient, inconvenience for installation and maintenance and huge later maintenance cost. The standard F65 microalloyed steel belongs to low carbon steel and has poor hardenability, namely the microalloyed steel is generally adopted in pipelines in large quantity and has the mark of X65. In the pipeline application in the field of oil and gas pipelines, the wall thickness of the steel pipe is relatively thin (the wall thickness is less than 100 mm). The forging needs to consider standardization and modularization of product structure design, and the design and selection of material dimension of the forging have to face the challenges of large wall thickness and supercritical state. When the wall thickness of the forging exceeds 100mm, the weldability limit (carbon equivalent requirement-Ce, welding crack sensitivity coefficient-Pcm) is comprehensively considered, the strength and toughness of the forging exceed the material performance limit, instability is generated, the strength and low-temperature toughness cannot be matched, and the control is extremely difficult.

When using ordinary F65 grade material, the yield strength at the center of the forging is below 450MPa with guaranteed impact performance, the same results are also seen in italian well known deep sea forging manufacturers and no solution has been obtained; and when the process is adjusted to ensure that the yield strength of the central position of the forging reaches the requirement of 450MPa, the single lowest phenomenon which does not meet the requirement appears in the low-temperature impact test results at-29 ℃ and-46 ℃, and the deviation of three impact values of the same group is extremely large and has a difference of more than 10 times.

Disclosure of Invention

In order to solve the problems of poor weldability, unstable strength and toughness and low temperature resistance of the existing F65 grade material after the wall thickness exceeds 100mm, the invention provides a deep-sea natural gas pipeline testing pressure cap and an F65M super-large wall thickness high-strength forging for a butt joint hub.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: the production process of the F65M super-large wall thickness high-strength forging for the deep-sea natural gas pipeline test pressure cap and the butt joint hub comprises the following steps:

a. blanking: taking a steel billet with the chemical components by weight percentage of less than or equal to 0.12 percent of C, 0.2 to 0.45 percent of Si, 1.1 to 1.4 percent of Mn, less than or equal to 0.01 percent of S, less than or equal to 0.015 percent of P, 0.1 to 0.5 percent of Cr, 0.5 to 0.99 percent of Ni, 0.15 to 0.5 percent of Mo, 0.02 to 0.055 percent of Al, less than or equal to 0.02 percent of Nb, less than or equal to 0.06 percent of V, less than or equal to 0.005 percent of Ca, less than or equal to 0.025 percent of Ti, less than or equal to 0.015 percent of Sn, less than or equal to 0.02 percent of Sb, less than or equal to 0.02 percent of As, less than or equal to 0.01 percent of Pb, less than or equal to 0.01 percent of Bi, less than or equal to 0.0005 percent of B, less than or equal to 0.3 percent of Cu, less than or equal to 2ppm of H, less than or equal to 0.012 percent of N, less than or equal to 25ppm of O and 0.4 to 0.45 percent of Cev As a raw material;

b. forging: placing the steel billet into a forging furnace, firstly heating the steel billet to 800 ℃ and preserving heat for more than or equal to 2 hours, then heating the steel billet at 800 ℃ to 1180 +/-20 ℃ and preserving heat for more than or equal to 3.5 hours, then forging the steel billet, forging the steel billet into a forged piece with an inner hole, controlling the initial forging temperature to be 1180 +/-20 ℃ and the final forging temperature to be 850 +/-20 ℃ in the forging process, controlling the drawing ratio to be more than 3:1, the upsetting ratio to be more than 2:1 and the total forging ratio to be more than 6:1 in the forging process, and cooling the forged piece to room temperature after the forging is finished;

c. normalizing, quenching and tempering: firstly, heating the forging to 580 ℃ and preserving heat for 1.5h, then heating the forging at 580 ℃ to 960 +/-10 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 hour/inch (inch is the maximum wall thickness dimension of the forging), and then air-cooling to room temperature; heating the forging to 580 ℃ and preserving heat for 1.5h, then heating the 580 ℃ forging to 920 +/-10 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 hour/inch (inch is the maximum wall thickness of the forging), then transferring the forging to cooling water within 90 seconds for water quenching to room temperature, and continuously spraying the cooling water into an inner hole on the forging by using a high-pressure fluid pump in the water quenching process; heating the forging to 200 ℃ and preserving heat for 1h, then heating the forging at 200 ℃ to 510 ℃ and preserving heat for 1.5h, finally heating the forging at 510 ℃ to 550 +/-8 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 h/inch (inch is the maximum wall thickness of the forging), and then air-cooling to room temperature;

d. and carrying out nondestructive inspection and machining.

Further, the deep sea natural gas pipeline test pressure cap and the F65M super-thick-wall-thickness high-strength forged piece for the butt joint hub are obtained through a smelting process of EF + LF + VD bottom pouring type vacuum protection pouring in the blanking step.

Further, the deep sea natural gas pipeline test pressure cap and the F65M super-thick-wall-thickness high-strength forging for the butt joint hub are adopted, wherein the heating rate in the forging process is controlled to be not higher than 125 ℃/h.

Further, the deep sea natural gas pipeline test pressure cap and the F65M super-thick-wall-thickness high-strength forged piece for the butt joint hub are characterized in that the heating rate in the normalizing, quenching and tempering processes is controlled to be not higher than 150 ℃/h.

The invention has the advantages that: the F65 rapid connector forging with the extra-large wall thickness produced by the production process has excellent weldability and low-temperature performance after the wall thickness exceeds 100mm, ensures the impact performance, has the yield strength of the center of the forging larger than 450MPa, and solves the problem that the single minimum requirement is not satisfied during low-temperature impact.

Detailed Description

The technical solution of the present invention will be further explained with reference to the preferred embodiments.

The invention relates to a production process of a deep sea natural gas pipeline test pressure cap and an F65M super-large wall thickness high-strength forging for a butt joint hub, which comprises the following steps:

a. blanking: taking a steel billet with the chemical components by weight percentage of less than or equal to 0.12 percent of C, 0.2 to 0.45 percent of Si, 1.1 to 1.4 percent of Mn, less than or equal to 0.01 percent of S, less than or equal to 0.015 percent of P, 0.1 to 0.5 percent of Cr, 0.5 to 0.99 percent of Ni, 0.15 to 0.5 percent of Mo, 0.02 to 0.055 percent of Al, less than or equal to 0.02 percent of Nb, less than or equal to 0.06 percent of V, less than or equal to 0.005 percent of Ca, less than or equal to 0.025 percent of Ti, less than or equal to 0.015 percent of Sn, less than or equal to 0.02 percent of Sb, less than or equal to 0.02 percent of As, less than or equal to 0.01 percent of Pb, less than or equal to 0.01 percent of Bi, less than or equal to 0.0005 percent of B, less than or equal to 0.3 percent of Cu, less than or equal to 2ppm of H, less than or equal to 0.012 percent of N, less than or equal to 25ppm of O and 0.4 to 0.45 percent of Cev As a raw material; then adopting a smelting process of EF + LF + VD bottom pouring type vacuum protection pouring;

b. forging: placing the steel billet into a forging furnace, heating the steel billet at a heating rate of not higher than 125 ℃/h, heating the steel billet to 800 ℃ and preserving heat for more than or equal to 2h, then heating the steel billet at 800 ℃ to 1180 +/-20 ℃ and preserving heat for more than or equal to 3.5h, then forging the steel billet, forging the steel billet into a forge piece with an inner hole, wherein in the forging process, the initial forging temperature is 1180 +/-20 ℃, the final forging temperature is 850 +/-20 ℃, in the forging process, the drawing ratio is more than 3:1, the upsetting ratio is more than 2:1, the total forging ratio is more than 6:1, and after the forging is finished, the forge piece is cooled to room temperature;

c. normalizing, quenching and tempering: heating the forge piece at a heating rate of not higher than 150 ℃/h, heating the forge piece to 580 ℃ and preserving heat for 1.5h, then heating the forge piece at 580 ℃ to 960 +/-10 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 hour/inch (inch is the maximum wall thickness of the forge piece), and then air-cooling to room temperature;

heating the forge piece at a heating rate of not more than 150 ℃/h, heating the forge piece to 580 ℃ and preserving heat for 1.5h, then heating the forge piece at 580 ℃ to 920 +/-10 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 hour/inch (inch is the maximum wall thickness dimension of the forge piece), then transferring the forge piece into cooling water within 90 seconds to carry out water quenching to room temperature, and continuously spraying the cooling water into an inner hole on the forge piece by using a high-pressure fluid pump in the water quenching process;

heating the forge piece at a heating rate of not higher than 150 ℃/h, heating the forge piece to 200 ℃ and preserving heat for 1h, then heating the forge piece at 200 ℃ to 510 ℃ and preserving heat for 1.5h, finally heating the forge piece at 510 ℃ to 550 +/-8 ℃ and preserving heat, controlling the heat preservation time to be 0.5-1 hour/inch (inch is the maximum wall thickness dimension of the forge piece), and then air-cooling to room temperature;

d. and carrying out nondestructive inspection and machining.

The mechanical test results of the F65M forging with extra-large wall thickness and high strength manufactured by the production process are as follows:

serial number	Performance of	Index (I)
			1	Tensile strength	The core performance of the product meets the requirements>＝530MPa
2	Yield strength	The core performance of the product meets the requirements>＝450MPa
			3	Elongation after fracture	A≥18％
4	Impact temperature	-46℃
			5	Impact (J)	≥50/38