Piercing plug for rolling high-alloy steel pipe and preparation method of piercing plug

Abstract

The invention discloses a piercing plug for rolling a high-alloy steel pipe and a preparation method thereof, the piercing plug comprises a plug base body and a reinforced alloy head, the plug base body is of a conical structure, the reinforced alloy head is fixedly connected with the head of the plug base body to form the piercing plug, and a high-strength alloy layer is arranged on the piercing plug; the reinforced alloy head is made of molybdenum alloy; the high-strength alloy layer is made of cobalt-based alloy. According to the piercing plug, the brazing molybdenum alloy head is designed at the head of the plug base body, the problem of nose collapse of the head of the plug is solved, the high-strength alloy layer is arranged on the outer wall of the piercing plug formed by the plug base body and the reinforced alloy head, the hardness and the abrasion resistance of the piercing plug are improved, and the service life of the plug is further prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of steel pipe piercing plugs, in particular to a piercing plug for rolling a high-alloy steel pipe and a preparation method thereof. Background Art

[0002] The piercing plug is one of the most consumed key tools in the production of seamless steel pipes. Due to the harsh working conditions of the piercing plug, the service life of the plug is short, which in turn affects the quality of the steel pipe and production efficiency. At present, the service life of the plug used for piercing ordinary carbon steel and low-alloy steel is basically the same, but the service life of the plug varies greatly when piercing high-alloy steel, and the individual differences of the same plug also vary greatly, and the service life is unstable. Currently, steel mills mainly use molybdenum-grade alloy plugs, which are expensive and have a complicated use process. They require preheating, water-free, glass powder lubrication, etc., and their service life is unstable, which seriously affects the production rhythm and product quality of high-alloy steel pipes. There is an urgent need for a piercing plug with stable service life, simple and controllable use process, and economical and applicable. The most important factor affecting the service life of the plug is the quality of the plug surface coating. How to achieve strong adhesion and continuous regeneration of the coating is the core of this technology. Therefore, it is necessary to design a piercing plug for high-alloy steel pipe rolling. Summary of the Invention

[0003] The object of the present invention is to overcome the deficiencies in the above-mentioned prior art and provide a piercing plug for rolling high-alloy steel pipes and a preparation method thereof. A brazed molybdenum alloy head is designed on the head of the plug base, which solves the problem of collapsed nose of the plug head. In addition, the outer wall of the piercing plug formed by the plug base and the reinforced alloy head is provided with a high-strength alloy layer, which improves the hardness and wear resistance of the piercing plug and further extends the service life of the plug.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is: a piercing plug for rolling high-alloy steel pipes, comprising a plug base and a reinforcing alloy head, the plug base being a conical structure, the bottom of the reinforcing alloy head being embedded in the top of the plug base and being fastened to the plug base to form a piercing plug, the piercing plug being provided with a high-strength alloy layer; the reinforcing alloy head being a molybdenum alloy; and the high-strength alloy layer being a cobalt-based alloy.

[0005] Preferably, the reinforced alloy head includes a top, a first connecting part and a second connecting part, the top is an arc-shaped structure, the horizontal part of the top is connected to the first connecting part, the side of the first connecting part away from the top is connected to the second connecting part, the side wall of the first connecting part is arc-shaped, and the side wall of the first connecting part is connected to the arc-shaped structure of the top.

[0006] Preferably, the base body of the plug is in a conical structure, the sidewall of the base body is arc-shaped and connected with the sidewall of the first connecting part, and the head of the base body is provided with a concave groove which is matched with the second connecting part to facilitate the embedding of the second connecting part in the concave groove.

[0007] Preferably, the thickness of the high-strength alloy layer is 0.5-2 mm.

[0008] Preferably, the molybdenum alloy comprises the following components in percentage by weight: Mo: 99.2-99.5%, Ti: 0.50%, and Zr: 0.08%.

[0009] Preferably, the cobalt-based alloy comprises the following components in percentage by weight: Co: 49-55%, Cr: 15-25%, W: 5-10%, Ni: 10-20%, Fe: 2-8%, B: 0.9-3%, and C: 1-4%.

[0010] Preferably, the high-strength alloy layer is added with hard alloy phase WC, and the molybdenum alloy is a titanium-zirconium-molybdenum alloy.

[0011] Preferably, the base body of the plug is made of one of 20CrNi3, 3Cr2W8V and 4Cr5MoSiV.

[0012] The application further discloses a preparation method of the high-alloy steel pipe rolling piercing plug.

[0013] Preferably, the temperature required for the vacuum sintering is 1000-1200 DEG C.

[0014] Compared with the prior art, the application has the following advantages:

[0015] 1. The application designs a brazed molybdenum alloy head at the head of the base body of the plug, solves the problem of nose collapse of the plug head, and the outer wall of the piercing plug formed by the base body and the reinforced alloy head is provided with a high-strength alloy layer, thereby improving the hardness and wear resistance of the piercing plug and further prolonging the service life of the plug.

[0016] 2. The outer periphery of the piercing plug is sintered with cobalt-based alloy by vacuum sintering, thereby improving the carrying capacity of the piercing plug under high temperature conditions and prolonging the service life of the piercing plug.

[0017] 3. The piercing plug adopts different materials according to the different mechanical properties required by the base body and the head, the head of the plug is a reinforced alloy head made of molybdenum alloy, thereby improving the head strength of the piercing plug and reducing the economic cost of the piercing plug.

[0018] The present invention is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the reinforced alloy head of the present invention;

[0021] Figure 3 It is a structural schematic diagram of the plug base of the present invention.

[0022] Description of the accompanying drawings:

[0023] 1—Plug base; 2—Reinforced alloy head; 3—Concave groove;

[0024] 4—piercing plug; 5—top; 6—first connecting part;

[0025] 7—Second connecting part; 8—Top rod. DETAILED DESCRIPTION

[0026] The present invention provides a piercing plug for high alloy steel pipe rolling, which has good high temperature strength and a service life of 2 to 5 times that of an original piercing plug.

[0027] like Figures 1 to 3 As shown, the present invention discloses a piercing plug for rolling high-alloy steel pipes, comprising a plug base 1 and a reinforcing alloy head 2. The plug base 1 is a conical structure, the bottom of the reinforcing alloy head 2 is embedded in the top of the plug base 1 and is fastened to the plug base 1 to form a piercing plug 4, and a high-strength alloy layer is provided on the piercing plug 4; the reinforcing alloy head 2 is a molybdenum alloy; and the high-strength alloy layer is a cobalt-based alloy.

[0028] In this embodiment, the reinforced alloy head 2 is made of molybdenum alloy, and the diameter of the plug base 1 gradually increases from top to bottom along the height direction. The reinforced alloy head 2 is installed on the top of the plug base 1 to prevent the nose of the perforating plug 4 from collapsing when the perforating plug 4 is working. A cobalt-based alloy is coated on the surface of the perforating plug 4 to improve the surface hardness and wear resistance of the perforating plug 4. When the perforating plug is working, the push rod 8 is connected to the plug base 1 through a quick connector tooling to facilitate the push rod 8 to push the perforating plug 4 forward.

[0029] The reinforced alloy head 2 includes a top 5, a first connecting part 6 and a second connecting part 7. The top 5 is an arc-shaped structure. The horizontal part of the top 5 is connected to the first connecting part 6. The side of the first connecting part 6 away from the top 5 is connected to the second connecting part 7. The side wall of the first connecting part 6 is arc-shaped, and the side wall of the first connecting part 6 is connected to the arc-shaped structure of the top 5.

[0030] In the embodiment, the top of the top head 5 is arc-shaped, the bottom of the top head 5 is horizontal, the first connecting part 6 is a conical structure, the diameter of the top of the first connecting part 6 is consistent with the diameter of the bottom of the top head 5, so that the side wall of the first connecting part 6 is seamlessly connected with the top head 5, the second connecting part 7 is a cylindrical structure, the diameter of the second connecting part 7 is consistent with the diameter of the bottom of the first connecting part 6, so that the side wall of the reinforced alloy head 2 composed of the top head 5, the first connecting part 6 and the second connecting part 7 is smooth, the perforation quality is improved, and the service life of the perforation top head 4 is increased.

[0031] In another possible embodiment, different from the above embodiment, the second connecting part 7 is arc-shaped away from the bottom of the first connecting part 6, the contact area of the second connecting part 7 with the top head base 1 is increased, and the stability of the connection between the reinforced alloy head 2 and the top head base 1 is improved.

[0032] The side wall of the top head base 1 is arc-shaped and connected with the side wall of the first connecting part 6, the head of the top head base 1 is provided with a concave groove 3, and the structure of the concave groove 3 is matched with the second connecting part 7 to facilitate the embedding of the second connecting part 7 in the concave groove 3.

[0033] In the embodiment, the concave groove 3 is a hollow cylindrical structure, the concave groove 3 is arranged at the center of the head of the top head base 1, the diameter of the concave groove 3 is consistent with the diameter of the second connecting part 7, and the concave groove 3 is tightly connected with the second connecting part 7.

[0034] Further, the bottom of the concave groove 3 is arc-shaped, which is matched with the arc-shaped structure of the bottom of the second connecting part 7, so that the second connecting part 7 fills the concave groove 3 completely.

[0035] In a possible embodiment, the second connecting part 7 is a square connecting block, the top of the second connecting part 7 along the length direction is fixedly connected with the center of the bottom of the first connecting part 6, the width of the second connecting part 7 is smaller than the diameter of the first connecting part 6, the concave groove 3 is arranged at the center of the head of the top head base 1, the size of the concave groove 3 is matched with the size of the second connecting part 7, and the end of the second connecting part 7 away from the first connecting part 6 is tightly attached to the bottom of the concave groove 3. At this time, the bottom of the first connecting part 6 is tightly attached to the head of the top head base 1, so that the reinforced alloy head 2 is tightly fixed on the top head base 1.

[0036] In another possible embodiment, the concave groove 3 horizontally penetrates the sidewall of the base body 1, the concave groove 3 is a hollow cavity with a small upper part and a large lower part, the second connecting part 7 has a shape matching that of the concave groove 3, the second connecting part 7 has a trapezoidal structure with a small upper part and a large lower part, the top of the second connecting part 7 is fastened to the first connecting part 6, the second connecting part 7 is horizontally inserted into the concave groove 3 along the opening of the sidewall of the concave groove 3, and the second connecting part 7 and the concave groove 3 are welded, both the concave groove 3 and the second connecting part 7 have a trapezoidal structure, and the fastening effect of the concave groove 3 on the second connecting part 7 is improved, that is, the penetration effect of the base body 1 on the strengthened alloy head 2 is improved.

[0037] The high-strength alloy layer has a thickness of 0.5-2 mm.

[0038] The molybdenum alloy comprises the following components in percentage by weight: Mo: 99-99.5%, Ti: 0.30-0.90%, and Zr: 0.08-0.15%.

[0039] The cobalt-based alloy comprises the following components in percentage by weight: Co: 49-55%, Cr: 15-25%, W: 5-10%, Ni: 10-20%, Fe: 2-8%, B: 0.9-3%, and C: 1-4%.

[0040] The design principle of each component in the cobalt-based alloy is as follows:

[0041] Co (cobalt): Since Co has the characteristic of high melting point, the addition of Co element in the cobalt-based alloy is beneficial to improving the load capacity, hot corrosion resistance, cold and hot fatigue resistance, and high-temperature creep resistance of the cobalt-based alloy under high-temperature conditions; however, if the content of Co is too high, the cost of the improvement project is increased, the performance-price ratio of the material is reduced, and the application range of the material is limited; therefore, the content of Co in the cobalt-based alloy is controlled to be 49-55%.

[0042] Cr (chromium): Cr can improve the oxidation resistance of the cobalt-based alloy under high temperature, and Cr combines with C to form chromium carbide to enhance the wear resistance of the cobalt-based alloy; however, if the content of Cr continues to increase, the addition amount of other alloy elements will be reduced, which is not conducive to the improvement of hardness and wear resistance; moreover, too high content of Cr will cause the billet to easily stick to the tool under high temperature and high pressure, resulting in failure or of the tool. Therefore, the content of Cr is controlled to be 15-25%.

[0043] W (tungsten): W can maintain the hardness and strength of the material under high temperature, and W forms stable carbide with C to enable the material to still have excellent cutting performance under high-temperature environment; however, too high content of W will easily form too much brittle phase such as intermetallic compound to reduce the toughness of the cladding layer, therefore, the content of W is controlled to be 5-10%.

[0044] Ni (nickel): Ni can improve the strength and toughness of the material, enhance corrosion resistance, and improve high-temperature performance. At the same time, Ni can also significantly reduce the oxidation of the material at high temperatures and slow down the penetration of oxygen into the material. However, if the Ni content is too high, the cost will increase, the cost-effectiveness of the material will decrease, and the application range of the material will be limited. Therefore, the Ni content is controlled at 10-20%.

[0045] Fe (Iron): Fe is the main component of steel. By adjusting the Fe content, the hardness, strength and corrosion resistance of the material can be significantly improved. Fe can improve the plasticity and toughness of cobalt-based alloys, improve machinability, and help reduce the Fe element content gradient between the cladding layer and the iron-based material, thereby reducing the difference between the dissimilar metals on both sides of the interface and improving the interface bonding strength. However, if the Fe element content is too high, it can reduce the high-temperature strength. Therefore, the Fe content is controlled at 2-8%.

[0046] B (boron): The main function of B is to increase the hardenability of steel, thereby saving other rare and precious metals, increasing the wettability between metals, reducing the sintering temperature while reducing the oxygen content in the coating, and playing a role in slag removal. Therefore, the content of B element is controlled at 0.9-3%.

[0047] C (Carbon): Element C combines with strong carbide-forming elements in the alloy to form stable carbides, which are distributed in the alloy matrix, effectively hindering grain growth and dislocation movement, and improving the high-temperature strength of the alloy. In addition, the high hardness of carbides can significantly improve the wear resistance of the alloy and extend the service life of alloy components in high-temperature environments. An appropriate amount of element C helps to form a dense oxide film, improving the alloy's antioxidant and corrosion resistance. Therefore, the content of element C is controlled at 1-4%.

[0048] The high-strength alloy layer contains a hard alloy phase WC, and the molybdenum alloy is a titanium-zirconium-molybdenum alloy.

[0049] The plug substrate 1 is made of one of 20CrNi3, 3Cr2W8V and 4Cr5MoSiV.

[0050] The above-mentioned method for preparing a piercing plug for rolling a high-alloy steel pipe comprises the following steps: obtaining a plug base 1 by machining, welding a reinforcing alloy head 2 to the head of the plug base 1 to form a piercing plug 4, and sintering a cobalt-based alloy on the surface of the piercing plug 4 by vacuum sintering to obtain the piercing plug 4 for rolling a high-alloy steel pipe.

[0051] The temperature required for the vacuum sintering is 1000-1200°C.

[0052] The following describes a piercing plug for rolling high alloy steel pipes and a method for preparing the same.

[0053] Example 1

[0054] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 20CrNi3 steel, the components of the reinforcing alloy head 2 are as follows by weight: Mo: 99%, Ti: 0.90%, Zr: 0.1%; the components of the high-strength alloy layer are as follows by weight: Co: 49%, Cr: 15%, W: 10%, Ni: 20%, Fe: 2%, B: 3%, C: 1%.

[0055] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforcing alloy head 2 is 99%, the weight percentage of Ti is 0.90%, and the weight percentage of Zr is 0.1%, that is, the reinforcing alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 49%, the weight percentage of Cr is 15%, the weight percentage of W is 10%, the weight percentage of Ni is 20%, the weight percentage of Fe is 2%, the weight percentage of B is 3%, and the weight percentage of C is 1%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 0.5 mm.

[0056] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can pierce up to 30 times, which means that 30 super 13Cr steel pipes can be produced, which is 2.5 times that of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12 times).

[0057] Example 2

[0058] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 20CrNi3 steel, and the components of the reinforcing alloy head 2 are, by weight, 99.2% Mo, 0.68% Ti, and 0.12% Zr; the components of the high-strength alloy layer are, by weight, 50% Co, 25% Cr, 5% W, 10% Ni, 6% Fe, 2% B, and 2% C.

[0059] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.2%, the weight percentage of Ti is 0.68%, and the weight percentage of Zr is 0.12%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 50%, the weight percentage of Cr is 25%, the weight percentage of W is 5%, the weight percentage of Ni is 10%, the weight percentage of Fe is 6%, the weight percentage of B is 2%, and the weight percentage of C is 2%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 1 mm.

[0060] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed by the number of piercings. The piercing plug in this embodiment can pierce 28 times, which means that 28 super 13Cr steel pipes can be produced, which is 2.33 times that of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12 times).

[0061] Example 3

[0062] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 20CrNi3 steel, and the components of the reinforcing alloy head 2 are, by weight, 99.5% Mo, 0.42% Ti, and 0.08% Zr; the components of the high-strength alloy layer are, by weight, 52% Co, 15% Cr, 7% W, 15% Ni, 5% Fe, 2% B, and 4% C.

[0063] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.5%, the weight percentage of Ti is 0.42%, and the weight percentage of Zr is 0.08%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 52%, the weight percentage of Cr is 15%, the weight percentage of W is 7%, the weight percentage of Ni is 15%, the weight percentage of Fe is 5%, the weight percentage of B is 2%, and the weight percentage of C is 4%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 1 mm.

[0064] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can achieve 25 piercings, which means that 25 super 13Cr steel pipes can be produced, which is 2.08 times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12).

[0065] Example 4

[0066] like Figure 1 As shown, the plug base 1 of the piercing plug for rolling high-alloy steel pipes in this embodiment is made of 20CrNi3 steel, and the components of the reinforcing alloy head 2 are, by weight, 99.5% Mo, 0.30% Ti, and 0.15% Zr; the components of the high-strength alloy layer are, by weight, 55% Co, 20% Cr, 5% W, 10% Ni, 8% Fe, 0.9% B, and 1.1% C.

[0067] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.5%, the weight percentage of Ti is 0.30%, and the weight percentage of Zr is 0.15%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 55%, the weight percentage of Cr is 20%, the weight percentage of W is 5%, the weight percentage of Ni is 10%, the weight percentage of Fe is 8%, the weight percentage of B is 0.9%, and the weight percentage of C is 1.1%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 2 mm.

[0068] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed by the number of piercings. The piercing plug in this embodiment can pierce 27 times, which means that 27 super 13Cr steel pipes can be produced, which is 2.25 times the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12 times).

[0069] Example 5

[0070] like Figure 1As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 3Cr2W8V steel, the components of the reinforcing alloy head 2 are as follows by weight: Mo: 99%, Ti: 0.90%, Zr: 0.1%; the components of the high-strength alloy layer are as follows by weight: Co: 49%, Cr: 15%, W: 10%, Ni: 20%, Fe: 2%, B: 3%, C: 1%.

[0071] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforcing alloy head 2 is 99%, the weight percentage of Ti is 0.90%, and the weight percentage of Zr is 0.1%, that is, the reinforcing alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 49%, the weight percentage of Cr is 15%, the weight percentage of W is 10%, the weight percentage of Ni is 20%, the weight percentage of Fe is 2%, the weight percentage of B is 3%, and the weight percentage of C is 1%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 0.5 mm.

[0072] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can pierce up to 60 times, which means that 60 super 13Cr steel pipes can be produced, which is five times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12 times).

[0073] Example 6

[0074] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 3Cr2W8V steel, and the components of the reinforcing alloy head 2 are, by weight, 99.2% Mo, 0.68% Ti, and 0.12% Zr; the components of the high-strength alloy layer are, by weight, 50% Co, 25% Cr, 5% W, 10% Ni, 6% Fe, 2% B, and 2% C.

[0075] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.2%, the weight percentage of Ti is 0.68%, and the weight percentage of Zr is 0.12%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 50%, the weight percentage of Cr is 25%, the weight percentage of W is 5%, the weight percentage of Ni is 10%, the weight percentage of Fe is 6%, the weight percentage of B is 2%, and the weight percentage of C is 2%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 1 mm.

[0076] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can achieve 56 piercings, meaning that 56 super 13Cr steel pipes can be produced, which is 4.66 times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12).

[0077] Example 7

[0078] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 3Cr2W8V steel, and the components of the reinforcing alloy head 2 are, by weight, 99.5% Mo, 0.42% Ti, and 0.08% Zr; the components of the high-strength alloy layer are, by weight, 52% Co, 15% Cr, 7% W, 15% Ni, 5% Fe, 2% B, and 4% C.

[0079] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.5%, the weight percentage of Ti is 0.42%, and the weight percentage of Zr is 0.08%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 52%, the weight percentage of Cr is 15%, the weight percentage of W is 7%, the weight percentage of Ni is 15%, the weight percentage of Fe is 5%, the weight percentage of B is 2%, and the weight percentage of C is 4%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 1 mm.

[0080] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can achieve 55 piercings, meaning that 55 super 13Cr steel pipes can be produced, which is 4.58 times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12).

[0081] Example 8

[0082] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 3Cr2W8V steel, and the components of the reinforcing alloy head 2 are, by weight, 99.5% Mo, 0.30% Ti, and 0.15% Zr; the components of the high-strength alloy layer are, by weight, 55% Co, 20% Cr, 5% W, 10% Ni, 8% Fe, 0.9% B, and 1.1% C.

[0083] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.5%, the weight percentage of Ti is 0.30%, and the weight percentage of Zr is 0.15%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 55%, the weight percentage of Cr is 20%, the weight percentage of W is 5%, the weight percentage of Ni is 10%, the weight percentage of Fe is 8%, the weight percentage of B is 0.9%, and the weight percentage of C is 1.1%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 2 mm.

[0084] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can achieve 58 piercings, meaning that 58 super 13Cr steel pipes can be produced, which is 4.83 times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12).

[0085] Example 9

[0086] like Figure 1As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 4Cr5MoSiV steel, the components of the reinforcing alloy head 2 are as follows by weight: Mo: 99%, Ti: 0.90%, Zr: 0.1%; the components of the high-strength alloy layer are as follows by weight: Co: 49%, Cr: 15%, W: 10%, Ni: 20%, Fe: 2%, B: 3%, C: 1%.

[0087] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforcing alloy head 2 is 99%, the weight percentage of Ti is 0.90%, and the weight percentage of Zr is 0.1%, that is, the reinforcing alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 49%, the weight percentage of Cr is 15%, the weight percentage of W is 10%, the weight percentage of Ni is 20%, the weight percentage of Fe is 2%, the weight percentage of B is 3%, and the weight percentage of C is 1%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 0.5 mm.

[0088] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can pierce up to 50 times, which means that 50 super 13Cr steel pipes can be produced, which is 4.16 times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12 times).

[0089] Example 10

[0090] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 4Cr5MoSiV steel, and the components of the reinforcing alloy head 2 are, by weight, 99.2% Mo, 0.68% Ti, and 0.12% Zr; the components of the high-strength alloy layer are, by weight, 50% Co, 25% Cr, 5% W, 10% Ni, 6% Fe, 2% B, and 2% C.

[0091] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.2%, the weight percentage of Ti is 0.68%, and the weight percentage of Zr is 0.12%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 50%, the weight percentage of Cr is 25%, the weight percentage of W is 5%, the weight percentage of Ni is 10%, the weight percentage of Fe is 6%, the weight percentage of B is 2%, and the weight percentage of C is 2%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 1 mm.

[0092] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can achieve 41 piercings, meaning that 41 super 13Cr steel pipes can be produced, which is 3.41 times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12).

[0093] Example 11

[0094] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 4Cr5MoSiV steel, and the components of the reinforcing alloy head 2 are, by weight, 99.5% Mo, 0.42% Ti, and 0.08% Zr; the components of the high-strength alloy layer are, by weight, 52% Co, 15% Cr, 7% W, 15% Ni, 5% Fe, 2% B, and 4% C.

[0095] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.5%, the weight percentage of Ti is 0.42%, and the weight percentage of Zr is 0.08%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 52%, the weight percentage of Cr is 15%, the weight percentage of W is 7%, the weight percentage of Ni is 15%, the weight percentage of Fe is 5%, the weight percentage of B is 2%, and the weight percentage of C is 4%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 2 mm.

[0096] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed in terms of the number of piercings. The piercing plug in this embodiment can pierce up to 45 times, meaning that 45 super 13Cr steel pipes can be produced, which is 3.75 times the service life of the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12 times).

[0097] Example 12

[0098] like Figure 1 As shown, the plug base 1 of the piercing plug for high-alloy steel pipe rolling in this embodiment is made of 4Cr5MoSiV steel, and the components of the reinforcing alloy head 2 are, by weight, 99.5% Mo, 0.30% Ti, and 0.15% Zr; the components of the high-strength alloy layer are, by weight, 55% Co, 20% Cr, 5% W, 10% Ni, 8% Fe, 0.9% B, and 1.1% C.

[0099] First, according to the size of the perforated plug, the plug base 1 is machined to obtain a perforated plug base of a preset size, and a reinforcing alloy head 2 is vacuum brazed on the head of the plug base 1. The weight percentage of Mo in the reinforced alloy head 2 is 99.5%, the weight percentage of Ti is 0.30%, and the weight percentage of Zr is 0.15%, that is, the reinforced alloy head 2 is a molybdenum alloy; a high-strength alloy layer is sintered on the surfaces of the plug base 1 and the reinforcing alloy head 2 by vacuum brazing. The weight percentage of Co in the high-strength alloy layer is 55%, the weight percentage of Cr is 20%, the weight percentage of W is 5%, the weight percentage of Ni is 10%, the weight percentage of Fe is 8%, the weight percentage of B is 0.9%, and the weight percentage of C is 1.1%, that is, the high-strength alloy layer is a cobalt-based alloy; and the thickness of the high-strength alloy layer is 2 mm.

[0100] The above process produces a high-strength piercing plug that meets the rigidity required for piercing while also having good high-temperature resistance. The service life is expressed by the number of piercings. The piercing plug in this embodiment can pierce 46 times, that is, 46 super 13Cr steel pipes can be produced, which is 3.83 times the original piercing plug (which uses 20CrNi3 material and has a piercing frequency of 12 times).

[0101] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A piercing plug for high alloy steel pipe rolling, characterized by: The invention comprises a plug base (1) and a reinforced alloy head (2), wherein the plug base (1) is a conical structure, the bottom of the reinforced alloy head (2) is embedded in the top of the plug base (1) and is tightly connected to the plug base (1) to form a perforated plug (4), and the perforated plug (4) is provided with a high-strength alloy layer; The reinforced alloy head (2) is a molybdenum alloy; The high-strength alloy layer is a cobalt-based alloy.

2. A piercing plug for rolling a high alloy steel pipe according to claim 1, characterized in that: The reinforced alloy head (2) comprises a tip (5), a first connecting portion (6) and a second connecting portion (7); the tip (5) is an arc-shaped structure; the horizontal portion of the tip (5) is connected to the first connecting portion (6); the side of the first connecting portion (6) away from the tip (5) is connected to the second connecting portion (7); the side wall of the first connecting portion (6) is an arc-shaped structure; and the side wall of the first connecting portion (6) is connected to the arc-shaped structure of the tip (5).

3. A piercing plug for high alloy steel pipe rolling according to claim 2, characterized in that: The side wall of the plug base (1) is arc-shaped and connected to the side wall of the first connecting portion (6). The head of the plug base (1) is provided with a concave groove (3). The structure of the concave groove (3) matches the second connecting portion (7) so that the second connecting portion (7) is easily embedded in the concave groove (3).

4. A piercing plug for rolling a high alloy steel pipe according to claim 1, characterized in that: The thickness of the high-strength alloy layer is 0.5-2 mm.

5. The piercing plug for high alloy steel pipe rolling according to claim 1, characterized in that: The molybdenum alloy includes the following components by weight percentage: Mo: 99.2-99.5%, Ti: 0.50%, and Zr: 0.08%.

6. The piercing plug for high alloy steel pipe rolling according to claim 1, characterized in that: The cobalt-based alloy includes the following components in weight percentage: Co: 49-55%, Cr: 15-25%, W: 5-10%, Ni: 10-20%, Fe: 2-8%, B: 0.9-3%, and C: 1-4%.

7. The piercing plug for high alloy steel pipe rolling according to claim 1, characterized in that: The high-strength alloy layer contains a hard alloy phase WC, and the molybdenum alloy is a titanium-zirconium-molybdenum alloy.

8. The piercing plug for high alloy steel pipe rolling according to claim 1, characterized in that: The plug base (1) is made of one of 20CrNi3, 3Cr2W8V and 4Cr5MoSiV.

9. A method for preparing a piercing plug for high alloy steel pipe rolling according to any one of claims 1 to 8, characterized in that: A plug base (1) is obtained by machining, a reinforcing alloy head (2) is welded to the head of the plug base (1) to form a perforated plug (4), and a cobalt-based alloy is sintered on the surface of the perforated plug (4) by vacuum sintering to obtain a perforated plug (4) for rolling a high-alloy steel pipe.

10. The method for preparing a piercing plug for high alloy steel pipe rolling according to claim 9, characterized in that: The temperature required for the vacuum sintering is 1000-1200°C.

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