CN103266249A - Vanadium titanium carbide hard alloy and drilling bit prepared from same and preparation method - Google Patents

Abstract

The invention discloses a vanadium titanium hard alloy and a drilling bit prepared from the same. The vanadium titanium hard alloy comprises the following components: titanium carbide, vanadium carbide and the balance of iron and inevitable impurities. A vanadium titanium carbide alloy bit prepared from the vanadium titanium hard alloy disclosed by the invention does not adopt tungsten in a traditional bit preparation material, the consumption of strategic reserve resources is reduced, and the manufacturing cost of the bit is reduced. The bit preparation method disclosed by the invention adopts an integrated forming technology, obviously simplifies the preparation process of a drilling bit, and effectively reduces the bit cost.

Description

A kind of vanadium carbide titanium cemented carbide and the drilling bit prepared therefrom and its preparation method

technical field

The invention relates to a hard alloy drilling bit, in particular to a vanadium carbide titanium hard alloy drilling bit and a manufacturing method thereof. the

Background technique

Due to the need to impact and break hard rock formations during oil drilling, the drill bit material used is usually high-strength diamond or cemented carbide. The cemented carbide material used in the drill bit in the prior art is mainly cobalt-bonded tungsten carbide cemented carbide, and its hardness is usually 84-94 HRA. Tungsten and cobalt are strategic reserve resources, and the reserves in the earth's crust are relatively small, and the price is high, which directly leads to the high cost of oil drilling bits. the

At the same time, the drill bits in the prior art mostly adopt the welding method of preparation: first, the main part of the drill bit is respectively cast with steel, and the cobalt-bonded tungsten carbide cemented carbide is prepared by powder metallurgy, and then the cemented carbide is welded by welding. On the surface of the main part of the drill bit, a tungsten-cobalt cemented carbide drill bit is prepared. In this preparation method, the main part of the drill bit and the hard alloy blade part need to be formed separately, and then welded. The phenomenon of welding failure leads to the damage of the whole drill bit. the

Contents of the invention

The purpose of the present invention is to overcome the shortage of tungsten and cobalt scarce resources and high cost in the prior art, to provide a vanadium-titanium carbide cemented carbide with equivalent hardness, and a steel-bonded vanadium-titanium carbide The drill bit is made of cemented carbide, and the invention also provides a casting process in which the steel-bonded vanadium carbide titanium carbide and the main body of the drill are formed at one time by casting. the

In order to realize the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A vanadium-titanium carbide hard alloy contains the following components by weight percentage, 85% to 95% of the hard phase, and the balance is iron and unavoidable impurities. The hard phase is vanadium titanium carbide, wherein the vanadium/titanium molar ratio is not greater than 1. the

The hard phase in cemented carbide is vanadium-titanium carbide. If a single titanium carbide is used as the hard phase to prepare cemented carbide, the sintering temperature is 1400-1450°C. Adding an appropriate amount of vanadium carbide can reduce the sintering of cemented carbide. Temperature, the sintering temperature of vanadium carbide titanium carbide is 1390-1420 ℃. This is because when vanadium carbide and titanium carbide form vanadium-titanium carbide, lattice defects are generated, which increases the internal energy of the lattice, thereby activating the lattice, which is beneficial to the migration of substances and the dissolution of hard phases. In addition, adding an appropriate amount of vanadium carbide can improve the morphology of the hard phase, from the irregular titanium carbide hard phase to the spherical vanadium titanium carbide hard phase, thereby improving the performance of the cemented carbide. the

It is particularly preferred that the vanadium/titanium molar ratio is 0.3 to 0.5, which can significantly improve the hardness of the cemented carbide. The hardness of cemented carbide is significantly higher than that of cemented carbide prepared using titanium carbide alone. the

Iron is used as the bonding phase in cemented carbide, and after iron is used as the bonding phase, the bonding performance between the cemented carbide and the substrate is significantly improved. the

Further, the vanadium-titanium carbide hard alloy also includes the following elements by weight percentage, copper 0.10-0.30%. Since the melting point of copper is only 1083°C, which is lower than that of steel, copper can increase the liquid phase in vanadium-titanium carbide cemented carbide during alloy forming, which is beneficial to improve the densification of cemented carbide, thereby improving the drill bit edge. hardness. The amount of copper should not be too much or too little. Although the melting point of copper is low, the liquid phase can be increased after adding to improve the densification of the cemented carbide, but too little copper can hardly achieve the effect of increasing the liquid phase. The performance effect is not obvious; too much copper will reduce the hardness of the alloy and affect the performance of the alloy. the

Further, the vanadium-titanium carbide hard alloy also includes the following element by weight percentage, 0.03-0.15% of yttrium. Yttrium can refine the grains of vanadium-titanium carbide cemented carbide and strengthen the grain boundaries, thereby increasing the hardness of the drill bit. the

Further, the raw materials for the above-mentioned vanadium-titanium carbide hard alloy also include copper powder and/or yttrium-iron alloy powder. Copper 0.10-0.30%, Yttrium 0.03-0.15%. the

The hardness of the vanadium carbide titanium hard alloy is 86-95HRA. the

Application of the above-mentioned vanadium carbide-titanium carbide in the preparation of drilling bits. the

A method for preparing the vanadium-titanium carbide drill bit as described above, comprising the following steps:

(1) Weigh titanium carbide, vanadium carbide, graphite, reduced iron powder, copper, and yttrium-iron alloy powder in proportion. the

(2) Mix the raw materials weighed in step (1), grind them finely in a protective environment isolated from air, and pass through a 320-500 mesh sieve to obtain powder pellets, dry them, and then add 1wt%-1.5wt% polyethylene glycol Alcohol solution, fully stirred, passed through a 45-60 mesh sieve to obtain granules. the

(3) Put the granules into the mold and press them with a pressure of 350-700MPa for 10-60s to obtain a compact. the

(4) Place the compact in a vacuum furnace, pre-sinter at 200-350°C for 30-120 minutes, and the absolute pressure inside the vacuum furnace is less than or equal to 3Pa. the

(5) Put the block pre-sintered in step (4) into the mold, and pour molten steel, so that the block is densified under the heat of molten steel, and vanadium carbide interacts with titanium carbide to form vanadium-titanium carbide. Finally, a vanadium carbide titanium carbide drill bit is obtained. the

The yttrium-iron alloy powder contains 70% by weight of yttrium, and the balance is iron. the

After the raw materials are mixed in step (2), the protective environment for isolating air is inert gas protection, vacuum protection or adding absolute ethanol for isolating gas protection. It is preferred to use absolute ethanol to immerse the powder for air isolation protection, and to dry the powder granules after grinding can be natural drying or vacuum drying. The vacuum drying temperature is 100-200°C, and when it is higher than 250°C, side reactions between alloy raw materials are prone to occur, which will affect the final performance of the alloy. The molecular weight of the polyethylene glycol is 1450-6000. The solvent in the polyethylene glycol solution is a volatile organic solvent, such as methanol, ethanol, ether, chloroform, n-hexane, petroleum ether, etc. Anhydrous ethanol is preferred. The concentration is 1wt% ~ 40wt%, which is a concentration with suitable fluidity and convenient use. Add polyethylene glycol solution to make the finely ground powder pellets form pellets, and have a certain size difference and fluidity, so that it can be better controlled in the pressing process of step (3), and the molding effect is better, especially can Sufficient flow fills the dead corners, effectively improving the uniformity of the molding density of the compact during the pressing process, and avoiding the effect of subsequent sintering due to the incompact structure caused by the poor fluidity of the pellets. The 320-500 mesh sieves are Taylor sieves. Balance the particle size and component consumption of the finely ground pellets, and choose a 320-500 mesh sieve, which not only takes into account the effect of the pellets in the subsequent firing and molding, but also controls the time and cost of grinding, and at the same time avoids excessive grinding. Unfavorable accidents caused by long-term grinding treatment, such as powder oxidation, difficult operation, etc. the

Further, the grinding process in step (2) is processed by a ball mill, the ball-to-material ratio is 6:1-20:1, the ball-milling time is 48-120 hours, and the speed of the ball mill is 150-300 r/min. During the ball milling process, the proportion of balls, milling time and rotating speed have a great influence on the grinding effect of raw materials. If the proportion of ball material is too low during the grinding process, the time is too short, or the speed is slow and the strength is low, the grinding effect of each material will be uneven, which will eventually lead to the change of the proportion of each raw material in the sieved powder, making the subsequent molding The content of various elements in the billet is different from the design, which seriously affects the strength and performance of the alloy, and even fails to achieve the design effect. the

In step (3), a pressure of 350-700 MPa is selected for pressing, and the pressing time is 10-60 s. Taking into account the particle size and fluidity of the ground pellets, pressing under this pressure not only ensures that the pressed compact has sufficient strength, but also can maintain a good structure during the process of pouring molten steel, and will not be affected by If the pressing is too strong, the heat transfer of molten steel will be blocked, and the forming effect of the briquette will be affected. the

The temperature of the pre-sintering process in step (4) does not exceed 350°C. If the temperature is too high, the pores in the compact will be discontinuous, and isolated closed cells will be formed, which will hinder the heat transfer of molten steel and make it difficult to achieve densification of the compact. If it is too low, it will be difficult to completely volatilize the polyethylene glycol solution used in the auxiliary preforming, which will affect the performance of the final formed alloy drill bit poured into molten steel. At the same time, the heating rate in step (4) is preferably 3-10°C/min. On the one hand, the heating rate is too fast, which may lead to the cracking of the block, and on the other hand, the effect of volatilization of the polyethylene glycol solution is not good, and may affect The cavity in the block structure leads to the hardness, strength and shear force resistance of the alloy drill bit formed after pouring molten steel. If the heating rate is too slow, the compact will be at the pre-sintering temperature for a long time, the possibility of side reactions will increase, and even the carbonization reaction of polyethylene glycol itself will form organic carbonized impurities, which cannot be removed from the compact. Seriously affect the performance of cast alloy drill bits, resulting in unqualified products. the

In step (5), the molten steel is poured into the mold, and the pre-sintered compact interacts with the molten steel. On the one hand, the liquid phase sintering is carried out, and the hardening is completed through the liquid phase flow and particle rearrangement phase, the dissolution-precipitation phase, and the solid phase sintering phase. sintering densification of alloys. On the other hand, the vanadium carbide in the cemented carbide compact reacts with titanium carbide to form vanadium titanium carbide. After the molten steel is solidified, the vanadium-titanium carbide is fused with the steel to prepare a drill bit. Furthermore, before the molten steel is poured, an appropriate amount of ferromanganese and ferrosilicon are added for deoxidation treatment, and the deoxidation process is maintained for 2 to 5 minutes. Reducing the oxygen content in the steel can significantly improve the properties of the steel matrix. the

Further, the cemented carbide also contains 0.20-0.40% of silicon, 0.40-0.70% of manganese, 0.80-1.10% of chromium, and 0.15-0.25% of molybdenum. Silicon, manganese, chromium, and molybdenum are specially added to the cemented carbide to enhance the strength of the steel matrix. Silicon and manganese elements can dissolve into the steel matrix to form a solid solution, which improves the strength of the steel matrix. At the same time, silicon and manganese have strong deoxidation capabilities, which can remove oxygen in cemented carbide, and the resulting silicon dioxide and manganese oxide have higher The hardness can improve the performance of the alloy material. Chromium and iron can form solid solutions and metal compounds to increase the strength of steel. In terms of heat treatment, chromium can significantly improve the hardenability of steel. Molybdenum and iron can also form solid solutions and metal compounds to increase the strength of steel. Furthermore, molybdenum is a strong carbide-forming element. In terms of heat treatment, molybdenum can improve the hardenability, red hardness and prevent temper brittleness of steel. When steel-bonded vanadium-titanium carbide cemented carbide is sintered, molybdenum will undergo morphological changes and redistribution, that is, an unbalanced solid solution of vanadium-titanium carbide-molybdenum carbide will be formed at the edge of vanadium-titanium carbide grains, which will help improve the bonding phase of the steel. Wettability between vanadium carbide and titanium. Moreover, silicon, manganese, chromium, and molybdenum exist in the alloy at the same time, which can synergistically make the alloy have better heat treatment performance, and make the formed alloy easier to form martensite in the process of quenching and tempering. Increase the strength of the alloy. the

Further, it is preferable to use 35CrMo steel for pouring molten steel. 35CrMo steel contains trace amounts of silicon, manganese, chromium, and molybdenum, which are the same as the doping components in the alloy and have similar proportions, which can enhance the integrity between the steel matrix and the alloy material, and prevent the The difference between the base material and the alloy material forms an interfacial layer structure. The base body of the drilling bit formed of 35CrMo steel and the alloy blade are integrally formed, with high bonding strength, and will not be damaged due to collision with the hard rock layer during drilling. the

Further, the pouring temperature of the molten steel in step (5) is 1570-1580°C. By adopting the above-mentioned preparation process, the alloy drill bit is integrally formed. The temperature of the molten steel is the key to the sintering and densification of the alloy compact, and the key to the reaction of titanium carbide and vanadium carbide to form vanadium titanium carbide. The use of molten steel at 1570-1580°C can well complete the densification of the compact and can better improve the quality of titanium carbide. The reaction speed between vanadium carbide and the crystal phase structure of vanadium carbide titanium alloy is optimized. the

Compared with the prior art, the present invention has beneficial effects: the vanadium carbide titanium alloy prepared by the present invention does not need to use tungsten in the preparation material of traditional drill bits, and reduces the consumption of strategic reserve resources. When used as a material for preparing drilling bits, the cost can be effectively reduced. The preparation method of the drill bit provided by the invention adopts an integral molding process, which significantly simplifies the drill bit preparation process and effectively reduces the cost of the drill bit. the

Detailed ways

The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention. All proportions in the following examples that are not specifically stated are percentages by weight. the

Example 1

Vanadium carbide-titanium hard alloy, composition weight percentage: titanium carbide 64%, vanadium carbide 23%, and the balance is iron. Alloy hardness 90.8HRA. the

Example 2

Vanadium carbide-titanium hard alloy, composition weight percentage: titanium carbide 69.8%, vanadium carbide 20.2%, and the balance is iron. Alloy hardness 91.7HRA. the

Example 3

Calculate and weigh titanium carbide, vanadium carbide, graphite, and reduced iron powder. The components are represented by weight percentage: 77% of titanium carbide, 16% of vanadium carbide, and the balance is iron. Then put the above powder into a stainless steel ball mill tank, and perform ball milling on a planetary ball mill to mix the powder. The weight ratio of the ball to material is 10:1. Add absolute ethanol to the ball mill tank, and the absolute ethanol just completely submerges the powder. For 60 hours, the rotational speed of the ball mill was 180r/min. Pass the ground powder through a 320 mesh sieve and let it dry naturally. Then add a polyethylene glycol solution (PEG molecular weight 1450, solvent is absolute ethanol, concentration 22wt%) of 1% of the total mass of raw materials, fully stir to make it a pellet with a certain size and fluidity, and pass through a 45-mesh sieve . Put the above-mentioned pellets into a mould, press and form, the pressing pressure is 400MPa, and the pressing time is 15 seconds. Finally, put the pressed compact into a vacuum sintering furnace for pre-sintering. The sintering temperature is 300°C, the heating rate is 5°C/min, and the heat preservation is 60min. piece. Place the carbide slab into the mold. Put 35CrMo steel into the crucible, heat and melt, after the steel is completely melted, raise the temperature to 1520-1600°C and keep it warm, then add an appropriate amount of ferromanganese and ferrosilicon for deoxidation, let it stand for 3 minutes, and pour it into the mold at 1570-1580°C , the cemented carbide block placed in the mold is under the action of the heat of molten steel, on the one hand, the densification of the cemented carbide block is completed, and on the other hand, the vanadium carbide in the cemented carbide block interacts with titanium carbide to form vanadium carbide titanium. After the molten steel is solidified, the vanadium carbide-titanium carbide and 35CrMo steel are fused together to prepare the drill bit. The prepared steel-bonded vanadium carbide-titanium carbide drill bit has a hardness of 92.6HRA at the cutting edge. the

Example 4

Steel-bonded vanadium carbide-titanium carbide drill bit, the composition is weight percent: 68.4% titanium carbide, 21.6% vanadium carbide, 0.2% copper, and the balance is iron. The hardness of the drill bit is 93.3HRA. the

Comparative example 3, after adding copper, because the melting point of copper is lower than steel, so molten steel is poured in the mold, when steel bonded vanadium carbide titanium hard alloy utilizes heat to finish densification, the addition of copper can increase vanadium titanium carbide The liquid phase in the cemented carbide is conducive to improving the densification of the cemented carbide, so the hardness of the cutting edge of the drill bit is improved. the

Example 5

Calculate and weigh titanium carbide, vanadium carbide, graphite, reduced iron powder, copper powder, and yttrium-iron alloy powder (the content of yttrium is 70wt%). Then put the weighed powder into a stainless steel ball mill jar, and perform ball milling on a planetary ball mill to mix the powder. The weight ratio of the ball to material is 10:1. Add absolute ethanol into the ball mill jar, and the absolute ethanol just completely submerges the powder. material, the ball milling time was 60 hours, and the ball mill rotating speed was 180r/min. Pass the ground powder through a 400-mesh sieve and let it dry naturally. Then add a polyethylene glycol solution (PEG molecular weight 6000, solvent is absolute ethanol, concentration 10wt%) of 1.5% of the total mass of raw materials, and fully stir to make it a pellet with a certain size and fluidity, and pass through a 60-mesh sieve . Put the above-mentioned pellets into a mould, press and form, the pressing pressure is 400MPa, and the pressing time is 15 seconds. Finally, put the pressed compact into a vacuum sintering furnace for pre-sintering. The sintering temperature is 300°C, the heating rate is 3°C/min, and the heat preservation is 60min. piece. Place the carbide slab into the mold. After the steel is completely melted, heat it up to 1520-1600°C and keep it warm, then add an appropriate amount of ferromanganese and ferrosilicon for deoxidation, let it stand for 3 minutes, pour it into the mold at 1570-1580°C, and place the cemented carbide billet in the mold Under the action of the heat of molten steel, on the one hand, the densification of the cemented carbide compact is completed, and on the other hand, vanadium carbide in the cemented carbide compact interacts with titanium carbide to form vanadium titanium carbide. After the molten steel is solidified, the vanadium-titanium carbide is fused with the steel to prepare a drill bit. the

Steel-bonded vanadium carbide-titanium carbide drill bit, the composition is weight percent: titanium carbide 67.5%, vanadium carbide 26.2%, copper 0.2%, yttrium 0.15%, and the balance is iron. The hardness of the drill bit is 93.7HRA. the

Compared with Example 4, after adding yttrium, yttrium can further refine the crystal grains, strengthen the grain boundaries, and improve the hardness of the cutting edge of the drill bit. the

Embodiment 6～12

The preparation process of Examples 6-12 is the same as that of Example 5, and the proportion of each component is shown in Table 1. The hardness of the sintered cemented carbide is shown in Table 1. the

Table 1 Vanadium Carbide Titanium Carbide Drill Bits

It can be seen from Examples 6 to 12 that the proportion of vanadium carbide in the cemented carbide drill bit in vanadium carbide and titanium increases, and the hardness of the cemented carbide first increases and then decreases. When the molar ratio of vanadium/titanium reaches 0.4, the hardness of the cemented carbide reaches the maximum . the

Example 13

Vanadium carbide-titanium carbide, composition weight percentage: titanium carbide 76.8%, vanadium carbide 15.2%, silicon 0.20-0.40%, manganese 0.40-0.70%, chromium 0.80-1.10%, molybdenum 0.15-0.25%, and the balance is iron . Alloy hardness 91.5HRA. the

Comparative example 1

The implementation process is the same as in Example 3, and the heating rate is 15° C./min during the pre-sintering process. After the pre-sintering is completed, the compact cracks. the

Comparative example 2

The implementation process is the same as that of Example 3, and the pouring temperature of the molten steel is 1520-1530°C. The prepared drilling bit has a hardness of 89.8HRA. Because the pouring temperature of molten steel is lower and the heat provided is less, there are pores in the cemented carbide as the drill bit, the density is lower, and the hardness of the drill bit is lower. the

Comparative example 3

The implementation process is the same as that of Example 3, and the pouring temperature of the molten steel is 1620-1630°C. The prepared drilling bit has a hardness of 90.6HRA. Because the pouring temperature of molten steel is too high, more heat is provided, and the vanadium-titanium carbide particles in the cemented carbide as the drill bit blade and the grains of the binder phase steel are relatively coarse, and the hardness of the drill bit is reduced. In addition, because the molten steel pouring temperature is too high, the molten steel is oxidized seriously, and incomplete deoxidation treatment will reduce the bonding strength between the drill bit and the substrate. the

Claims (10)

1. a vanadium carbide titanium Wimet is characterized in that, comprises following component in percentage by weight, hard phase 85%～95%, and surplus is iron and unavoidable impurities; Described hard is the vanadium carbide titanium mutually, and wherein vanadium/titanium mol ratio is not more than 1.

2. according to the described Wimet of claim 1, it is characterized in that vanadium/titanium mol ratio is 0.3～0.5.

3. according to claim 1 or 2 described Wimet, it is characterized in that, also comprise the bonding phase in the Wimet, described bonding is iron mutually.

4. according to the arbitrary described Wimet of claim 1-3, it is characterized in that, also comprise the element of following weight percent, copper 0.10-0.30%.

5. according to the arbitrary described Wimet of claim 1-4, it is characterized in that, also comprise the element of following weight percent, yttrium 0.03-0.15%.

6. according to the arbitrary described Wimet of claim 1-5, it is characterized in that described vanadium carbide titanium Wimet hardness is 86～95HRA.

7. according to the application of the arbitrary described Wimet of claim 1-6 in the preparation petroleum drilling bit.

8. the preparation method of the drilling bit of a vanadium carbide titanium Wimet may further comprise the steps:

(1) takes by weighing titanium carbide, vanadium carbide, graphite, reduced iron powder, copper, yttrium iron alloy powder in proportion;

(2) raw material that step (1) is taken by weighing mixes, and is levigate under the protection environment of secluding air, crosses 320～500 mesh sieves, obtain the powder pellet, drying adds 1wt%～1.5wt% polyglycol solution then, fully stir, cross 45～60 mesh sieves, obtain particulate material;

(3) particulate material is put into mould, with the pressure compression moulding of 350～700MPa, compacting duration 10～60s gets briquet;

(4) briquet is placed vacuum oven, under 200～350 ℃, presintering 30～120 minutes, the inner absolute pressure of vacuum oven is smaller or equal to 3Pa;

(5) will put into casting mold through the good briquet of step (4) presintering, and pour into molten steel, vanadium carbide and titanium carbide effect form the vanadium carbide titanium, obtain vanadium carbide titanium inserted drill.

9. described preparation method according to Claim 8 is characterized in that, heat-up rate is 3～10 ℃/min in the step (4).

10. described preparation method according to Claim 8 is characterized in that, also comprises in the step (1) taking by weighing the following composition of weight percent: silicon 0.20-0.40%, manganese 0.40-0.70%, chromium 0.80-1.10%, molybdenum 0.15-0.25%.