LIGHT WEIGHT CEMENTED CARBIDE FOR FLOW EROSION COMPONENTS

Abstract

A cemented carbide for a flow component for controlling the pressure and flow of well products includes in wt %: about 7 to about 9 Co; about 5 to about 7 Ni; about 19 to about 24 Ti C; about 1.5 to about 2.5 Cr.sub.3C.sub.2; about 0.1 to about 0.3 Mo and balance of WC. A cemented carbide for fluid handling components and seal ring a comprises in wt %: about 1 to about 30 Ti C; about 12 to about 20 Co+Ni; about 0.5 to about 2.5 Cr; about 0.1 to about 0.3 Mo and balance of WC. A cemented carbide for fluid handling components and seal ring a comprises in wt %: about 15 to about 30 Ti C; about 5 to about 20 Ni; about 0.5 to about 2. Cr; about 0.5 to about 2.5 Mo and balance of WC.

Claims

1. A cemented carbide for a flow component for controlling the pressure and flow of well products, the cemented carbide having a composition comprising in wt % (weight %) of: about 7 to about 9 Co; about 5 to about 7 Ni; about 19 to about 24 TiC; about 1.5 to about 2.5 Cr.sub.3C.sub.2; about 0.1 to about 0.3 Mo; and balance WC.

2. The cemented carbide for a flow component of claim 1, wherein the composition comprises about 20 to about 22 wt % TiC.

3. The cemented carbide for a flow component according to claim 1, wherein the composition comprises from about 1.8 to about 2.2 wt % Cr.sub.3C.sub.2.

4. The cemented carbide for a flow component according to claim 1, wherein the composition comprises from about 5.3 to about 6.0 wt % Ni.

5. The cemented carbide for a flow component according to claim 1, wherein the composition comprises from about 8.0 to about 8.6 wt % Co.

6. The cemented carbide for a flow component according to claim 1, wherein the composition comprises from about 0.15 to about 0.25 wt % Mo.

7. The cemented carbide for a flow component according to claim 1, wherein the composition comprises WC of from about 50 wt % to about 69 wt %.

8. The cemented carbide for a flow component according to claim 1, wherein the composition has a density of from about 9.6 to about 10.2 g/cm.sup.3.

9. A cemented carbide for fluid handling components and seal rings, the cemented carbide having a composition comprising in wt %: about 15 to about 30 TiC; about 12 to about 20 Co+Ni; about 0.5 to about 2.5 Cr.sub.3C.sub.2; about 0.1 to about 0.3 Mo; and balance WC.

10. The cemented carbide for fluid handling components and seal rings of claim 9, wherein the composition comprises from about 19.8 to about 21.8 wt % TiC.

11. The cemented carbide for fluid handling components and seal rings according to claim 9, wherein the composition comprises from about 1.8 to about 2.2 wt % Cr.sub.3C.sub.2.

12. The cemented carbide for fluid handling components and seal rings according to claim 9, wherein the composition comprises from about 5.3 to about 5.9 wt % Ni.

13. The cemented carbide for fluid handling components and seal rings according to claim 9, wherein the composition comprises from about 7.9 to about 8.5 wt % Co.

14. The cemented carbide for fluid handling components and seal rings according to claim 9, wherein the composition comprises from about 0.15 to about 0.25 wt % Mo.

15. The cemented carbide for fluid handling components and seal rings according to claim 9, wherein the composition comprises WC in an amount of from about 62.2 to about 64.2 wt %.

16. The cemented carbide for fluid handling components and seal rings according to claim 9, wherein the composition has a density of from about 9.6 to about 10.2 g/cm.sup.3.

17. The cemented carbide for fluid handling components and seal rings according to claim 9, wherein the composition has an average WC grain size of from about 4 μm to about 8 μm.

18. A cemented carbide for fluid handling components and seal rings, the cemented carbide having a composition comprising in wt %: about 15 to about 30 TiC; about 5 to about 20 Ni; about 0.5 to about 2.5 Cr; about 0.5 to about 2.5 Mo; and the balance WC.

19. The cemented carbide for fluid handling components and seal rings of claim 18, wherein the composition comprises from about 20 to about 23 wt % TiC.

20. The cemented carbide for fluid handling components and seal rings of claim 18, wherein the composition comprises from about 0.8 to about 1.5 wt % Cr.sub.3C.sub.2.

21. The cemented carbide for fluid handling components and seal rings according to claim 18, wherein the composition comprises from about 9.5 to about 14.5 wt % Ni.

22. The cemented carbide for fluid handling components and seal rings according to claim 18, wherein the composition comprises from about 0.7 to about 1.6 wt % Mo.

23. The cemented carbide for fluid handling components and seal rings according to claim 18, wherein the composition has a density of from about 9.8 to about 10.4 g/cm.sup.3.

24. The cemented carbide for fluid handling components and seal rings according to claim 18, wherein cemented carbide composition has an average WC grain size of from about 9.9 μm to about 1.3 μm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 is an optical microscopy image of an embodiment of the present disclosure of cemented carbide for a flow control apparatus and a seal ring.

[0038] FIG. 2 is a scanning electron microscope (SEM) image of the embodiment of FIG. 1.

[0039] FIG. 3 is an SEM image of another embodiment of FIG. 1.

[0040] FIG. 4 is an SEM image of a comparative example.

[0041] FIG. 5 is an SEM image of an embodiment of cemented carbide for a seal ring.

[0042] FIG. 6 is an SEM image of another embodiment of cemented carbide for a seal ring.

[0043] FIG. 7 is an SEM image of another embodiment of cemented carbide for a seal ring.

[0044] FIG. 8 is an SEM image of another embodiment of cemented carbide for a seal ring.

DETAILED DESCRIPTION

[0045] As used herein, the term “about” means plus or minus 10% of the numerical value of the number with which it is being used. Therefore, about 50% means in the range of 45%-55%.

[0046] As will be described fully herein, embodiments of the present disclosure relate to cemented carbides for flow components (herein, the term “component” means parts or pieces), particularly for seal rings and for choke trim components used in the oil and gas industry, where the components are subjected to high pressures of multi-media fluid and where there is a corrosive environment, particularly for choke valve components whose primary function of which is to control the pressure and flow of well products, such as pumps. Under severe conditions of multi flow media; these components may suffer from extreme mass loss by exposure to solid particle erosion, acidic corrosion erosion-corrosion synergy and cavitation mechanisms even when fitted with cemented carbide trims. The components will also suffer due to galvanic corrosion due to a electropotential difference between the binder and the housing for the flow control part.

[0047] The light weight cemented material can also be used in, for example, seal rings, to reduce the weight of the seal ring. In order to improve the corrosion resistance the light weight cemented carbide of the present disclosure can have a Ni—Cr—Mo binder.

[0048] An embodiment of a light weight cemented carbide for use in flow components, such as seal rings has a composition in wt % of about 15 to about 30 TiC, about 12 to about 20 Co+Ni, about 0.5 to about 2.5 Cr; and about 0.1 to about 0.3 Mo and the balance WC. The WC may have an average sintered grain size of about 0.5 μm. The sintered structure is also shown in FIGS. 1 and 2.

[0049] Seal rings are the key critical component in mechanical shaft seals for pumps. Cemented carbide show a good mechanical performance in this kind of application. The cemented carbide seal rings of the present disclosure have a reduced weight and therefore allow for less energy consumption. Furthermore, the cemented carbide seal rings have improved application relevant properties, such as improved corrosion resistance.

[0050] Referring to FIG. 1, the first cemented carbide for a flow component, LW, as defined hereinabove or hereinafter and used, for example, in a flow control apparatus, has the following composition ranges in weight %: about 7 to about 9 wt % Co, about 5 to about 7 wt % Ni, about 19 to about 24 wt % TiC, about 1.5 to about 2.5 wt % Cr.sub.3C.sub.2, about 0.1 to about 0.3 wt % Mo and the balance WC.

[0051] The hardness of the cemented carbide component as defined hereinabove or hereinafter may be of from about 1350 to about 1500 HV30 (IS03878), the toughness (KIc) being about 8.5 to about 9.5 MPa.Math.√m by indentation technique according to KIc (SEVNB)>8.5 MPa.Math.√m and the transverse rupture strength (TRS) according to IS03327 type C>1700 N/mm.sup.2.

[0052] The WC in the first, second or third cemented carbide may have an average sintered grain size of about 0.8 μm and the (Ti,W)C (titanium tungsten carbide) in the first, second or third cemented carbide may have an average sintered grain size of about 1.5 μm according to IS04499-2-2010.

[0053] The carbon content within the sintered cemented carbide as defined hereinabove or hereinafter should be kept within a narrow range in order to retain a high resistance to corrosion and wear, as well as have a high toughness. The carbon level of the sintered structure is held in the lower portion of the range between free carbon in the microstructure (top limit) and eta-phase initiation (bottom limit).

[0054] Magnetic saturation measurements for the magnetic binder phase of the sintered cemented carbide is expressed in terms of μT m.sup.3 kg-1 and relate to the nature of the combined multi element binder. For the sintered material according to the disclosure, this should lie between 80% and 90% of the 2-phase field of the binder. No eta-phase or graphite is permitted in the sintered structure. The sintered structure is shown in FIG. 1.

[0055] The re-passivity of the embodiment, depicted as LW is improved due to the significant addition of TiWC hard phase added to the composition. Corrosion resistance was determined using the ASTM G61. ASTM G61 covers a procedure for conducting potentiodynamic polarization measurements. See Table 1 below showing the results of ASTM G61 comparing an embodiment with a comparative example.

TABLE-US-00001 TABLE 1 ASTM G61 Evaluated parameters from polarization curves Eb Eb Ereprass Product 10 μm/cm.sup.2 100 μm/cm.sup.2 10 μm/cm.sup.2 Comparative 24 46 −333 Example LW 118 156 −76

[0056] “Eb” is the breakdown potential, at which localised corrosion occurs and is evaluated at two different criteria. The lower criterion of 10 μA/cm.sup.2 may be considered to give an indication of the ease of initiation of corrosion. The difference between this and the higher criterion of 100 μA/cm.sup.2 provides an indication of the propagation process.

[0057] “Erepass” is the potential required to repassivate the specimen

[0058] Conventional powder metallurgical methods such as milling, drying, pressing, shaping, sintering and sinter hipping, which are used for manufacture of conventional cemented carbides are used to manufacture the embodiments of the present disclosure.

EXAMPLES

[0059] It should be appreciated that the following examples are illustrative, non-limiting example. The compositions and results of the embodiments are shown in Tables 2 and 3 below.

[0060] In the examples below the powders were sourced from the following suppliers: (W,Ti)C from Zhuzhou or HC Starck, Co from Umicore or Freeport, Ni from Inco, Mo from HC Starck and Cr.sub.3C.sub.2 from Zhuzhou or HC Starck

Example 1 (‘LW Flow Control’—Reference A)

[0061] Cemented carbide grades with the composition in wt-% 21 TiC; 8.3 Co; 5.7; Ni; 0.2 Mo and 2 Cr.sub.3C.sub.2 with the balance of WC was produced using WC and (Ti,W)C powder with an average FSSS particle size (d.sub.50) of 0.8 μm and about 3 μm, respectively. The cemented carbide samples were prepared from powders forming the hard constituents and powders forming the binder. The powders were wet milled together with lubricant and anti-flocculating agent until a homogeneous mixture was obtained and granulated by drying. The dried powder was pressed on the Tox press to bodies and ‘green machined’ before sintering. Sintering was performed at 1360-1410° C. for about 1 hour in vacuum, followed by applying a high pressure, 50 bar Argon, at sintering temperature for about 30 minutes to obtain a dense structure before cooling.

[0062] The sintered cemented carbide structure comprises of some hexagonal WC with an average grain size of 0.8 μm together with (Ti,W)C grains with an average grain size of 1.5 μm as measured using the linear intercept method.

[0063] The material has a hardness of about 1350 to about 1500 HV30 depending on the selected composition and sinter temperature.

[0064] As shown in FIG. 3, the embodiment of the first cemented carbide disclosure, LW shows improved wear resistance to scratch testing in comparison to a comparative example of a fine grained oil and gas grade with 10.5 wt % binder (FIG. 4) with similar or hardness values. Testing was carried out using a diamond stylus with a 20 μm radius tip at 200 mN.

[0065] Wear resistance damage from scratching is considerably improved for an embodiment of the disclosure, LW, as shown by reduced ‘grey’ amorphous damage in FIG. 3 as compared to the comparative example in FIG. 4. Further, corrosion resistance for an embodiment of the disclosure, LW, in seawater is improved and with better repassivity (See Table 1).

[0066] The hardness of the cemented carbide component may be about 1350 to about 1500 HV30 (IS03878), the toughness (KIc) being about 8.7 MPa.Math.√m using Palmqvisst toughness technique according to IS028079 or KIc (LW15, SEVNB)>8.5 MPa.Math.√m and the transverse rupture strength (TRS) according to IS03327 type C>1700 N/mm.sup.2.

Example 2 (‘LW Seal Ring’—Reference B)

[0067] A cemented carbide grades with the compositions in wt-% of about 63.2 WC; about 20.8 TiC; about 2 Cr.sub.3C.sub.2; about 8.2 Co; about 5.6 Ni and about 0.2 Mo was produced using WC powder with an average FSSS particle grain size (d.sub.50) of 4-8 μm, respectively. The sintered structure is shown in FIG. 5.

[0068] The cemented carbide samples were prepared from powders forming the hard constituents and powders forming the binder. The powders were wet milled together with lubricant and anti-flocculating agent until a homogeneous mixture was obtained and granulated by drying. The dried powder was pressed on the Tox press to bodies and ‘green machined’ before sintering. Sintering is performed at 1360-1410° C. for about 1 hour in vacuum, followed by applying a high pressure, 50 bar Argon, at sintering temperature for about 30 minutes to obtain a dense structure before cooling.

[0069] Another embodiment of the light weight cemented carbide for seal rings according to the present disclosure, (LW+CR), has a composition of about 15 to about 30 wt % TiC, about 5 to about 20 wt % Ni, about 0.5 to about 2.5 wt % Cr, and about 0.5 to about 2.5 wt % Mo and the balance WC.

Example 3 (‘LW+CR Seal Ring’—Reference C)

[0070] A cemented carbide grades with the compositions in wt-% of about 66.04 WC; about 21.95 TiC; about 0.95 Cr.sub.3C.sub.2; about 0.95 Mo; about 10.11 Ni using WC and (Ti,W)C powder with an average FSSS particle size (d.sub.50) of greater than about 1 μm, for example 1.1 and 1.15 μm, respectively. It should be appreciated that a particle size of up to about 8 μm can be used.

[0071] The sintered structure is shown in FIG. 6.

[0072] The cemented carbide samples were prepared from powders forming the hard constituents and powders forming the binder. The powders were wet milled together with lubricant and anti-flocculating agent until a homogeneous mixture was obtained and granulated by drying. The dried powder was pressed on the Tox press to bodies and ‘green machined’ before sintering. Sintering is performed at 1360-1410° C. for about 1 hour in vacuum, followed by applying a high pressure, 50 bar Argon, at sintering temperature for about 30 minutes to obtain a dense structure before cooling.

[0073] The hardness of the cemented carbide component may be about 1550 HV30 (IS03878), the toughness (KIc) being about 8.5 MPa.Math.√m using Palmqvist toughness technique according to ISO28079 and a density of about 10.2 g/cm.sup.3.

Example 4 (‘LW+CR Seal Ring’—Reference D)

[0074] A cemented carbide grades with the compositions in wt-% of about 62.79 WC; about 20.86 TiC; about 1.29 Cr.sub.3C.sub.2; about 1.29 Mo; about 13.78 Ni WC and (Ti,W)C powder with an average FSSS particle size (d.sub.50) of greater than about 1 μm, for example 1.1 and 1.15 μm, respectively. It should be appreciated that a particle size of up to about 8 μm can be used.

[0075] The cemented carbide samples were prepared from powders forming the hard constituents and powders forming the binder. The powders were wet milled together with lubricant and anti-flocculating agent until a homogeneous mixture was obtained and granulated by drying. The dried powder was pressed on the Tox press to bodies and ‘green machined’ before sintering. Sintering is performed at 1360-1410° C. for about 1 hour in vacuum, followed by applying a high pressure, 50 bar Argon, at sintering temperature for about 30 minutes to obtain a dense structure before cooling.

[0076] The sintered structure is shown in FIGS. 7 and 8.

[0077] The hardness of the cemented carbide component may be about 1390 to about 1400 HV30 (IS03878), the toughness (KIc) being about 8.6 to about 9.3 MPa.Math.√m using Palmqvist toughness technique according to ISO28079 and a density of about 10.02 to about 10.17 g/cm3.

[0078] The grades disclosed herein demonstrate improved corrosion resistance in comparison to a standard seal ring grade. Corrosion resistance was determined using a modified test to ASTM G61. ASTM G61 covers a procedure for conducting potentiodynamic polarization measurements. The modification of this standard has been in the media used. Instead of using 3.5% NaCl solution in the tests, artificial seawater according to ASTM D1141 was used as the media. Furthermore, the flushed port cell used in ASTM G61 was replaced by sealing the specimen with epoxy to avoid crevice corrosion on the edge of the sample.

[0079] The pitting potential was used as a measure for comparison. The higher the value the better the corrosion resistance of the material. The value measured for a standard seal ring grade was Epit=263 mV SCE. However, for the LW grade Epit=318 mV SCE showing improved corrosion resistance.

TABLE-US-00002 TABLE 2 Ref A B C D Sample LW flow LW seal LW + CR seal LW + CR control ring ring seal ring WC (wt %) balance 63.2 66.04 62.79 WC grain size 0.8 4.0-8.0 1.05-1.15 1.05-1.15 (μm) TiC (wt %) 21 20.8 21.95 20.86 Co (wt %) 8.3 8.2 0 0 Ni (wt %) 5.7 5.6 10.11 13.78 Mo (wt %) 0.2 0.2 0.95 1.29 Cr.sub.3C.sub.2 (wt %) 2 2 0.95 1.29

TABLE-US-00003 TABLE 3 Ref A C D Sample LW flow control LW + CR seal ring LW + CR seal ring Density 9.8-10  10.2 10.02-10.17 (gm/cm.sup.3) Hardness 1350-1500 1550 1390-1400 (Hv30) Toughness 9.5 8.5-9.5 8.6-9.3 (K1.sub.C)

Itemized List of Embodiments

[0080] 1. A cemented carbide for a flow component for controlling the pressure and flow of well products the cemented carbide having a composition comprising in wt % of:

[0081] balance WC;

[0082] 7 to 9 Co;

[0083] 5 to 7 Ni;

[0084] 19 to 24 TiC;

[0085] 1.5 to 2.5 Cr.sub.3C.sub.2; and

[0086] 0.1 to 0.3 Mo.

[0087] 2. The cemented carbide for a flow component of item 1, wherein the composition comprises WC in an amount of from 50 wt % to 69 wt %.

[0088] 3. The cemented carbide for a flow component of item 1 or 2, wherein the composition comprises 21 wt % TiC.

[0089] 4. The cemented carbide for a flow component of any of the preceding items, wherein the composition comprises 2 wt % Cr.sub.3C.sub.2.

[0090] 5. The cemented carbide for a flow component of any of the preceding items, wherein the composition comprises 5.7 wt % Ni.

[0091] 6. The cemented carbide for a flow component of any of the preceding items, wherein the composition comprises 8.3 wt % Co.

[0092] 7. The cemented carbide for a flow component of any of the preceding items, wherein the composition comprises 0.2 wt % Mo.

[0093] 8. The cemented carbide for a flow component of any of the preceding items, wherein the composition has a density of from 9.8 to 10 g/cm.sup.3, a hardness of from 1350 to 1550 HV30, a toughness of 9.5 MPa.Math.√m.

[0094] 9. The cemented carbide for a flow component of any of the preceding items, wherein the composition has an average WC grain size of about 0.8 μm.

[0095] 10. A cemented carbide for a seal ring, the cemented carbide having a composition comprising in wt %: [0096] balance WC; [0097] 15 to 30 TiC; [0098] 2 to 20 Co+Ni; [0099] 0.5 to 2.5 Cr.sub.3C.sub.2; and [0100] 0.1 to 0.3 Mo.

[0101] 11. The cemented carbide for fluid handling components and seal rings of item 10, wherein the composition comprises WC in an amount of 63.2 wt %.

[0102] 12. The cemented carbide for fluid handling components and seal rings of item 10 or 11, wherein the composition comprises 20.8 wt % TiC.

[0103] 13. The cemented carbide for fluid handling components and seal rings of any of items 10-12, wherein the composition comprises 2 wt % Cr.sub.3C.sub.2.

[0104] 14. The cemented carbide for fluid handling components and seal rings of any of items 10-13, wherein the composition comprises 5.6 wt % Ni.

[0105] 15. The cemented carbide for fluid handling components and seal rings of any of items 10-14, wherein the composition comprises 8.2 wt % Co.

[0106] 16. The cemented carbide for fluid handling components and seal rings of any of items 10-15, wherein the composition comprises 0.2 wt % Mo.

[0107] 17. The cemented carbide for fluid handling components and seal rings of any of items 10-16, wherein cemented carbide composition has an average WC grain size of about 0.8 μm.

[0108] 18. The cemented carbide for fluid handling components and seal rings of any of items 10-17, wherein the composition has a density of from 9.8 to 10 g/cm.sup.3, a hardness of from 1350 to 1550 HV30, and a toughness of from about 8.7 MPa.Math.√m.

[0109] 19. The cemented carbide for fluid handling components and seal rings of any of items 10-16, wherein cemented carbide composition has an average WC grain size of from about 4 μm to about 8 μm.

[0110] 20. A cemented carbide for fluid handling components and seal rings, the cemented carbide having a composition comprising in wt %:

[0111] 15 to 30 TiC;

[0112] 5 to 20 Ni;

[0113] 0.5 to 2.5 Cr.sub.3C.sub.2;

[0114] 0.5 to 2.5 Mo; and

[0115] balance WC.

[0116] 21. The cemented carbide for fluid handling components and seal rings of item 20, wherein the composition comprises WC in an amount of from 62 to 66 wt %.

[0117] 22. The cemented carbide for fluid handling components and seal rings of item 20 or 21, wherein the composition comprises of from 20 to 22 wt % TiC.

[0118] 23. The cemented carbide for fluid handling components and seal rings of any of items 20-22, wherein the composition comprises of from 0.95 to 1.3 wt % Cr.sub.3C.sub.2.

[0119] 24. The cemented carbide for fluid handling components and seal rings of any of items 20-23, wherein the composition comprises of from 10 to 14 wt % Ni.

[0120] 25. The cemented carbide for fluid handling components and seal rings of any of items 20-24, wherein the composition comprises of from 0.95 to 1.3 wt % Mo.

[0121] 26. The cemented carbide for fluid handling components and seal rings of any of items 20-25, wherein the composition has a density of from 10.02 to 10.2 g/cm.sup.3, a hardness of from 1390 to 1550 HV30 and a toughness of from 8.5 to about 9.3 MPa.Math.√m.

[0122] Although the present embodiments have been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.