阅读说明：本技术 一种10CrNi3MoV圆管坯及其制备方法和应用 (10CrNi3MoV round pipe blank and preparation method and application thereof ) 是由 李源 叶文冰 张健 王佳明 罗祥华 于 2020-06-02 设计创作，主要内容包括：本发明涉及钢铁冶金加工领域,公开了一种10CrNi3MoV圆管坯及其制备方法和应用,该方法包括以下步骤：(1)按配方量进行配料,依次进行电弧炉熔炼、钢包炉精炼、真空脱气精炼后,得到电渣自耗电极；(2)将步骤(1)所得电渣自耗电极进行电渣重熔得到钢锭；(3)当所述钢锭的锥度≤1.5％,进行去应力退火得到圆管坯；当所述钢锭的锥度＞1.5％,依次进行去应力退火、锻制和退火处理得到圆管坯。本发明方法制备的10CrNi3MoV圆管坯具有高纯净度、良好的韧性、极佳的成型性和耐腐蚀性,可用于制备综合性能优异的高压无缝钢管以及高压无缝钢瓶。(The invention relates to the field of ferrous metallurgy processing, and discloses a 10CrNi3MoV round pipe blank and a preparation method and application thereof, wherein the method comprises the following steps: (1) proportioning according to the formula amount, and sequentially carrying out electric arc furnace smelting, ladle furnace refining and vacuum degassing refining to obtain an electroslag consumable electrode; (2) carrying out electroslag remelting on the electroslag consumable electrode obtained in the step (1) to obtain a steel ingot; (3) when the taper of the steel ingot is less than or equal to 1.5%, performing stress relief annealing to obtain a round pipe blank; and when the taper of the steel ingot is larger than 1.5%, sequentially performing stress relief annealing, forging and annealing treatment to obtain the round pipe blank. The 10CrNi3MoV round pipe blank prepared by the method has high purity, good toughness, excellent formability and corrosion resistance, and can be used for preparing high-pressure seamless steel pipes and high-pressure seamless steel cylinders with excellent comprehensive performance.)

1. A preparation method of a 10CrNi3MoV round pipe blank is characterized by comprising the following steps:

(1) proportioning according to the formula amount, and sequentially carrying out electric arc furnace smelting, ladle furnace refining and vacuum degassing refining to obtain an electroslag consumable electrode;

(2) carrying out electroslag remelting on the electroslag consumable electrode obtained in the step (1) to obtain a steel ingot;

(3) when the taper of the steel ingot is less than or equal to 1.5%, performing stress relief annealing to obtain a round pipe blank; when the taper of the steel ingot is larger than 1.5%, sequentially performing stress relief annealing, forging and annealing treatment to obtain a round pipe blank;

in the step (2), the chemical components of the steel ingot are controlled as follows, wherein the total weight of the steel ingot is 100 percent: 0.07 to 0.14% of C, 0.17 to 0.37% of Si, 0.30 to 0.60% of Mn, 0.90 to 1.20% of Cr, 2.60 to 3.00% of Ni, 0.20 to 0.27% of Mo, 0.04 to 0.10% of V, and the balance of unavoidable impurities and Fe.

2. The method according to claim 1, wherein in step (1), the harmful elements in the electroslag consumable electrode are required to be: cu is less than or equal to 0.10 percent, S is less than or equal to 20ppm, P is less than or equal to 70ppm, and [ H ] is less than or equal to 2 ppm.

3. The method according to claim 1 or 2, wherein in step (2), the electroslag remelting adopts a quaternary electroslag slag system, and the electroslag slag system contains 55-70 wt% of CaF based on 100 wt% of the total weight of the electroslag slag system₂10 to 25 weight partsAmount% of Al₂O₃1-10 wt% of CaO and 2-10 wt% of MgO; the electroslag remelting requires that S is less than or equal to 10 ppm.

4. The method as claimed in claim 1, wherein in step (3), the forging temperature of the steel ingot is 1100-1250 ℃.

5. A method according to claim 1, wherein in step (3), the ingot is forged to a one-shot forging shape.

6. The method as claimed in claim 1, wherein in the annealing treatment after forging of the steel ingot in step (3), the annealing temperature is 650-700 ℃.

7. The method according to claim 1, wherein in the step (3), surface treatment is carried out after the round pipe blank is obtained;

preferably, the surface treatment is surface dressing or surface polishing.

8. Round pipe billet produced by the method according to any one of claims 1 to 7.

9. A seamless steel pipe produced from the round tube blank according to claim 8.

10. A seamless steel cylinder made from the seamless steel tube of claim 9.

Technical Field

The invention relates to the field of ferrous metallurgy processing, in particular to a 10CrNi3MoV round pipe blank and a preparation method and application thereof.

Background

The 10CrNi3MoV steel has good seawater corrosion resistance and seawater scouring resistance, is widely used for manufacturing marine equipment and environmental equipment, and has positive effects on the shock resistance and light weight manufacturing of ships due to good toughness.

At present, the circular tube blanks of the domestic similar section steel are mainly smelted by a converter or an electric arc furnace, and the high-pressure steel cylinder serving as a final product is mainly manufactured and molded by welding steel plates, and the welded high-pressure steel cylinder has the problems of poor toughness, welding quality risk of welding seams, poor performance consistency, easy corrosion of the welding seams, short service life of equipment structures and the like. Meanwhile, the high-pressure steel cylinder has high requirements on the purity of steel.

Therefore, the development of the 10CrNi3MoV round pipe blank for the high-pressure seamless steel cylinder solves the problems caused by the welded steel cylinder, and has a profound influence on the improvement of the overall quality of equipment.

Disclosure of Invention

The invention aims to provide a 10CrNi3MoV round pipe blank and a preparation method and application thereof.

The invention discloses a high-pressure welding steel cylinder which is prepared from a round tube blank of the same type of steel and has the problems of welding quality risk of a welding seam, poor performance consistency, easy corrosion of the welding seam, short service life of equipment structure and the like. After intensive research, the inventor of the invention also finds that when a steel ingot with a specific taper is prepared by adopting a specific smelting process, the prepared round pipe blank has high purity, good toughness, excellent formability and corrosion resistance, and the seamless steel pipe and the seamless steel cylinder forged by the round pipe blank have excellent comprehensive performance. Based on this, the present invention has been completed.

Specifically, the invention provides a preparation method of a 10CrNi3MoV round pipe blank, which comprises the following steps:

(1) proportioning according to the formula amount, and sequentially carrying out electric arc furnace smelting, ladle furnace refining and vacuum degassing refining to obtain an electroslag consumable electrode;

(2) carrying out electroslag remelting on the electroslag consumable electrode obtained in the step (1) to obtain a steel ingot;

(3) when the taper of the steel ingot is less than or equal to 1.5%, performing stress relief annealing to obtain a round pipe blank; when the taper of the steel ingot is larger than 1.5%, sequentially performing stress relief annealing, forging and annealing treatment to obtain a round pipe blank;

in the step (2), the chemical components of the steel ingot are controlled as follows, wherein the total weight of the steel ingot is 100 percent: 0.07 to 0.14% of C, 0.17 to 0.37% of Si, 0.30 to 0.60% of Mn, 0.90 to 1.20% of Cr, 2.60 to 3.00% of Ni, 0.20 to 0.27% of Mo, 0.04 to 0.10% of V, and the balance of unavoidable impurities and Fe.

Preferably, in step (1), the harmful elements in the electroslag consumable electrode are required to be: cu is less than or equal to 0.10 percent, S is less than or equal to 20ppm, P is less than or equal to 70ppm, and [ H ] is less than or equal to 2 ppm.

Preferably, in the step (2), a quaternary electroslag slag system is adopted for electroslag remelting, and the electroslag slag system contains 55-70 wt% of CaF based on 100% of the total weight of the electroslag slag system₂10 to 25% by weight of Al₂O₃1-10 wt% of CaO and 2-10 wt% of MgO; the electroslag remelting requires that S is less than or equal to 10 ppm.

Preferably, in the step (3), the forging temperature of the steel ingot is 1100-1250 ℃.

Preferably, in the step (3), the ingot is forged to be formed by one-shot forging.

Preferably, in the step (3), in the annealing treatment after forging the steel ingot, the annealing temperature is 650-700 ℃.

Preferably, in the step (3), after the round pipe blank is obtained, surface treatment is carried out; more preferably, the surface treatment is surface dressing or surface polishing.

The second aspect of the invention provides the round pipe blank prepared by the method.

A third aspect of the invention provides a seamless steel pipe produced from the round pipe blank described above.

In a fourth aspect, the present invention provides a seamless steel cylinder produced from the above seamless steel tube.

The method for preparing the 10CrNi3MoV round pipe billet adopts the modes of electric arc furnace, external refining and electroslag remelting, improves the density and purity of cast ingots, reduces the component segregation of steel ingots, and the round pipe billet prepared from the steel ingots with different tapers has high purity, good toughness, excellent formability and corrosion resistance.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a preparation method of a 10CrNi3MoV round pipe blank, which comprises the following steps:

(1) proportioning according to the formula amount, and sequentially carrying out electric arc furnace smelting, ladle furnace refining and vacuum degassing refining to obtain an electroslag consumable electrode;

(2) carrying out electroslag remelting on the electroslag consumable electrode obtained in the step (1) to obtain a steel ingot;

(3) when the taper of the steel ingot is less than or equal to 1.5%, performing stress relief annealing to obtain a round pipe blank; when the taper of the steel ingot is larger than 1.5%, sequentially performing stress relief annealing, forging and annealing treatment to obtain a round pipe blank;

in the step (2), the chemical components of the steel ingot are controlled as follows, wherein the total weight of the steel ingot is 100 percent: 0.07 to 0.14% of C, 0.17 to 0.37% of Si, 0.30 to 0.60% of Mn, 0.90 to 1.20% of Cr, 2.60 to 3.00% of Ni, 0.20 to 0.27% of Mo, 0.04 to 0.10% of V, and the balance of unavoidable impurities and Fe.

In the method of the invention, in the step (1), the harmful elements in the electroslag consumable electrode are required to be: cu is less than or equal to 0.10 percent, S is less than or equal to 20ppm, P is less than or equal to 70ppm, and [ H ] is less than or equal to 2 ppm; the specification of the electroslag consumable electrode can be selected conventionally in the field, and in a preferable case, the specification of the electrode is phi 300mm or phi 360 mm.

The high-quality electroslag consumable electrode is smelted by adopting electric arc furnace smelting, ladle furnace refining and vacuum degassing refining, so that impurity elements and gas in steel can be effectively removed, and the sulfur and phosphorus are removed. During electric arc furnace smelting, firstly, the decarbonization amount of steel is ensured, generally speaking, the decarbonization amount of alloy structural steel is not less than 0.30%, the decarbonization amount of 10CrNi3MoV steel is not less than 0.40%, and molten steel cannot be seriously oxidized, so that the phenomenon that the content of impurities in the steel is influenced due to incomplete removal of later-stage deoxidation products is avoided; in the external refining, the external smelting link is widely applied at home and abroad, and each manufacturer has a respective smelting mode. In order to give consideration to the refining and purification of molten steel and the accurate control of components, 10CrNi3MoV steel is refined, a refined desulfurization slag system is adopted, the slag system has the advantage that the sulfur content in the steel can be removed to the greatest extent, the sulfur content in the 10CrNi3MoV electroslag consumable electrode can be below 20ppm, and the cleanliness of the material is ensured. Compared with the traditional smelting, the method has the main difference that no aluminum or aluminum-containing deoxidizer is used in final deoxidation, deoxidation work is well done in the initial stage of reduction, no aluminum-containing deoxidizer is added in the later stage of reduction, and the cleanliness of the material can be effectively ensured. The principle is that after the aluminate inclusion is formed, the removal effect of electroslag is poor, and part of the aluminate inclusion is continuously deposited in a steel ingot, so that deoxidation work is required to be done at the initial stage of reduction in the smelting period outside the furnace, the conditions that the later-stage inclusion is formed and the removal effect is poor are reduced, and the purity of the material is favorably improved. In addition, the proper vacuum degassing temperature is ensured at the later stage of the stage, and the deoxidation and reduction requirements are sufficient; in the vacuum degassing refining, the degassing amount of the material is ensured by accumulating data and keeping the vacuum degree below 67Pa for 15 minutes. The degassing rate is related to the original gas content of molten steel, the effective carbon removal amount in the early-stage electric arc furnace smelting can reduce the pressure of later-stage vacuum degassing, and generally speaking, the hydrogen content [ H ] in the steel is less than or equal to 1.5ppm and [ N ] in the steel is less than or equal to 45ppm after the smelting operation is carried out on the steel.

In the method, in the step (2), a quaternary electroslag system with strong desulfurization is adopted for electroslag remelting, and the electroslag system contains 55-70 wt% of CaF (calcium fluoride) based on the total weight of the electroslag system being 100%₂10 to 25% by weight of Al₂O₃1-10 wt% of CaO and 2-10 wt% of MgO; the electroslag remelting requires that S is less than or equal to 10 ppm; the specification of the electroslag remelting ingot can be selected conventionally, and under the optimal condition, the specification of the electroslag remelting ingot is phi 550 mm.

Under the precondition of protecting electroslag remelting in protective atmosphere, the easily burnt elements in the steel ingot can be effectively controlled, the stability of chemical components of the steel ingot is improved, and meanwhile, the slag system has good slag inclusion removal and desulfurization capacity, so that the purity of the steel ingot is improved, and the finish of the steel ingot is good. By the electric arc furnace and slag adding duplex process, the material not only meets the technical requirements on purity, but also can provide high-quality steel ingots with uniform and compact structures for the next procedure, and the comprehensive performance of the material is improved.

In the invention, the taper of the steel ingot is less than or equal to 1.5 percent, which is beneficial to the smooth operation of the cross rolling pipe penetrating process and the hot rolling process in the seamless steel pipe rolling process, and simultaneously, the size difference of the head part and the tail part of the steel ingot before cross rolling pipe penetrating can be reduced by adopting a steel ingot machining mode, thereby preventing the surface malignant defect from occurring in the large-deformation cross rolling process and improving the surface quality of the seamless steel pipe.

In the invention, the steel ingot is subjected to stress relief annealing to obtain the round tube blank, so that the metal loss and the processing cost in the process of forming the forged tube blank are reduced, and the economic benefit of the product is obvious. In addition, the steel ingot is subjected to oblique rolling and pipe penetration after annealing, so that residual structure stress and temperature stress in the steel ingot can be effectively removed, and surface machining of the steel ingot is facilitated.

In the method of the present invention, in step (3), the forging temperature of the steel ingot is 1100-1250 ℃. Specifically, the forging temperature of the steel ingot may be 1100 ℃, 1150 ℃, 1200 ℃ or 1250 ℃. The forged round pipe blank is formed by one-time forging, and the temperature after forging is more than or equal to 850 ℃. The surface of the forged circular tube blank has no taper, so that the process of obliquely rolling and penetrating the tube in the process of forging the seamless steel tube is facilitated, and the rolling defects on the surface of the pierced billet are reduced.

In the method of the present invention, the forging heat number is a heating number in forging.

In the method, in the step (3), the annealing treatment is stress relief annealing after the forging and slow cooling to less than or equal to 200 ℃. The annealing temperature is not particularly required to be controlled, and the annealing temperature is only required to be favorable for removing the stress of the round tube blank. In specific embodiments, the annealing temperature is 650-700 ℃.

After the round tube blank is forged, annealing is carried out, so that residual structure stress and temperature stress of different degrees existing in the round tube blank can be removed, and the machining performance of the surface of the round tube blank is improved.

In the method of the invention, the surface treatment mode of the round pipe blank can be a conventional treatment mode in the field. Preferably, the surface treatment mode of the round pipe blank is surface grinding or surface polishing.

The second aspect of the present invention provides a round pipe blank produced by the above method.

The method for preparing the 10CrNi3MoV round pipe billet adopts the modes of electric arc furnace, external refining and electroslag remelting, improves the density and purity of cast ingots, reduces the component segregation of steel ingots, and the round pipe billet prepared from the steel ingots with different tapers has high purity, good toughness, excellent formability and seawater corrosion resistance.

A third aspect of the invention provides a seamless steel pipe produced from the round pipe blank described above.

In a fourth aspect, the present invention provides a seamless steel cylinder produced from the above seamless steel tube.

The 10CrNi3MoV high-pressure seamless steel tube prepared by the round tube billet and the high-pressure seamless steel cylinder prepared by the seamless steel tube solve the problems of equipment such as poor welding quality risk of welding seams, poor performance consistency, easy corrosion of the welding seams, short service life of equipment structures and the like, greatly prolong the service life of the equipment, basically meet the design requirement of the same service life of a gas cylinder and the equipment, and fill the blank of the equipment.

The present invention will be described in detail below by way of examples, but the scope of the present invention is not limited thereto.

The examples are used for illustrating the 10CrNi3MoV round pipe blank and the preparation method thereof provided by the invention.