WO2008109113A1

WO2008109113A1 - Tubular members with hard coating and method for making same

Info

Publication number: WO2008109113A1
Application number: PCT/US2008/002947
Authority: WO
Inventors: Robert Z. Reath; Alvin J. Kertesz
Original assignee: U.S. Chrome Corporation
Priority date: 2007-03-06
Filing date: 2008-03-06
Publication date: 2008-09-12

Abstract

The invention includes manufacturing processes and products made using these processes. An exemplary process includes providing a metallic tubular member for processing and subjecting the metallic tubular member to a substantially uniform radially inward clamping force along substantially its entire length. The method further includes refining the interior surface of the tubular member to improve the surface finish and concentricity of the interior surface, followed by applying a coating of material on the inner surface of the tubular member.

Description

Express Mail No. EV 155 278 366 US

TUBULAR MEMBERS WITH HARD COATING AND METHOD FOR MAKING SAME

CROSS-REFERENCE TO RELATED APPLICATION

[001] This application claims the benefit of priority from U.S. Provisional Patent

Application Serial No. 60/905,462 filed March 6, 2007, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

[002] The present invention relates to materials having hard coatings and methods for making materials having hard coatings. Particularly, the present invention is directed to methods for making improved tubular members having hard coatings as well as the tubular members so produced.

Description of Related Art

[003] A variety of methods are known in the art for providing materials, such as tubular members, with hard coatings on their interior.

[004] To reduce cost, tubes of relatively short length are generally fabricated by processing a longer "multiple length" tube and then dividing the multiple length tube into multiple tubes of shorter length. Inside diameters of long multiple length tubes are thus electroplated with hard coatings and honed prior to dividing them into the shorter individual tubes. For long tubes, however, the applied plating voltage drops along the length of the anode based on the anode resistance. This voltage drop, IR, decreases current density along the length of the anode resulting in a variation of coating thickness on the cathode. This effect is illustrated in Fig. l(A). Moreover, as the anode resistance (R) increases along the length of the anode, the variability of the coating thickness is magnified. [005] A variety of solutions have been proposed to eliminate this thickness variability. For example, in accordance with a first technique, a shorter length anode that is electrically connected to an insulated conductor may be slowly moved along the length of the cathode (e.g., along the inside diameter of a tube) as illustrated in Fig. 2. A uniform coating is deposited only over the short length of the tube ID. By making the anode shorter, the variability in the coating thickness may be reduced. The tube ID is thus plated uniformly by moving the short anode and the zone of uniform plating thickness to cover the entire tube

STM ₂45865 1 1 Express Mail No. EV 155 278 366 US length. Thicker and uniform coatings can be deposited using multiple passes. However, the moving anode electroplating process accordingly has a relatively low plating rate compared to that of a static anode having a length that corresponds to the entire length of the cathode. Moreover, the moving anode process is less economical than use of a static cathode. [006] Generally, in order to fabricate an inside diameter coated tube with superior concentricity and surface finish, a thick coating of hard material is generally electrodeposited along the inside of the tube. The coating is honed to final thickness with enhanced concentricity and surface finish. The coating is preferably thick enough to hone off any non- concentricity stemming from non-uniformity of coating thickness or from the starting ID of the tube prior to plating. Honing is generally performed in two stages. During a first state, a high material removal rate coarse honing is performed to eliminate gross non-concentricity and surface roughness. Second, a finish honing is performed with smaller cuts or polishing. [007] The relatively long tube needs to be firmly secured during honing. This is typically accomplished by way of mechanical clamping devices with uniformly distributed clamping pressure around the tube circumference. These clamping devices are placed along the length of the tube. Although the tube clamping pressure is uniform around the circumference proximate the clamping device, this pressure varies along the tube length as there is no clamping pressure in between the devices.

[008] The localized and non-uniform mechanical clamping results described above results in elastic deformation of the thin-wall tube as depicted in Fig. 3. specifically, the thin wall tube is elastically compressed at clamped areas which, when honed, introduce reduced coating thickness areas. After the honing operation, the clamps are released, and nonuniform coating thickness results. This effect is magnified with the clamping force - the higher the clamping force the higher the non-uniformity.

[009] Because of the slow plating rate of the moving anode and slow multiple stage honing of hard coating using mechanical clamping described above, the conventional manufacturing processes for providing interior coated tubular materials are expensive, even though these techniques involve the use of long tubes that may be separated into multiple shorter tubes.

[0010] As will be appreciated, there still exists a need for a lower-cost manufacturing process for thin-wall tubes with hard interior coatings having an enhanced concentricity and surface finish. The present invention provides a solution for these and other problems.

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SUMMARY OF THE INVENTION

[0011] Advantages of the present invention will be set forth in and become apparent from the description that follows. Additional advantages of the invention will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.

[0012] To achieve these and other advantages and in accordance with the purpose of the invention, as embodied herein, the invention includes a manufacturing process. The process includes providing a metallic tubular member for processing and subjecting the metallic tubular member to a substantially uniform radially inward clamping force along substantially its entire length. The method further includes refining the interior surface of the tubular member to improve the surface finish and concentricity of the interior surface, followed by applying a coating of material on the inner surface of the tubular member. [0013] In accordance with a further aspect of the invention, the coating of material is harder than the metallic tubular member. The tubular member may have a wall thickness, for example, between about 0.050 inches and about 0.150 inches. Preferably, the tubular member has a wall thickness of about 0.80 inches. The tubular member may be provided in any suitable length, such as between about 12 inches in length and about 36 inches in length. [0014] In accordance with another aspect of the invention, the clamping force may be applied to the tubular member using a clamp that is actuated by pressurizing a fluid in a reservoir. The fluid may be pressurized, for example, to a pressure between about 50 psi and about 100 psi. More preferably, the fluid is pressurized to a pressure between about 60 psi and about 80 psi. The clamp may be, for example, between about 5 inches in length and about 40 inches in length.

[0015] In accordance with still a further aspect of the invention, the refining step may include at least one of a honing process and a burnishing process. In accordance with a preferred embodiment, the inside diameter may be enlarged by up to about 0.02 inches during honing. In accordance with another embodiment, the inside diameter of the tubular member may be increased by between about 0.012 inches and about 0.20 inches in about a 50 second period during the refining step. As described herein, the honing may result in an interior tubular surface having a mean roughness between about 5 and about 10 microinches. If desired, the honing may include a multiple-step honing process, such as a three-step honing process.

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[0016] If desired, the interior surface of the tubular member may be burnished to improve the concentricity of the interior surface after honing and prior to the coating step. Burnishing may be carried out, for example, by way of roller burnishing. Honing may result in an interior tubular surface having a mean roughness between about 3 to about 4 microinches. Preferably, burnishing removes substantially all marks on the interior surface of the tubular member created during honing, if honing is performed. [0017] In accordance with yet another aspect of the invention, the coating may be applied using an electroplating process. Preferably, the electroplating process includes high deposition rate electroplating. In accordance with one embodiment, the electroplating process may be performed using an anode having a platinum-coated copper core. Even more preferably, the anode has a voltage drop along its length that is sufficiently low to facilitate formation of an electrodeposited coating on the tubular member having a substantially uniform thickness.

[0018] In accordance with still another aspect of the invention, the process may include masking the tubular member in at least one location prior to the coating step to prevent the masked location from being coated. For example, the tubular member may be masked proximate the ends of the tubular member. In accordance with another aspect of the invention, the coating may include at least one of a chromium material, a Co-P material and a Co-P electrocomposite coating.

[0019] In accordance with a further aspect of the invention, the process may further include at least one finishing step after the coating step. The at least one finishing step may include, for example, one or more honing, polishing or burnishing steps. The polishing step may include polishing the inside of the tubular member with a radially adjustable cylindrical mandrel including abrasive material disposed on its surface.

[0020] In further accordance with the invention, a manufacturing process is provided.

The process includes providing a metallic tubular member and subjecting the metallic tubular member to a substantially uniform radially inward clamping force along substantially its entire length. The method further includes refining the interior surface of the tubular member to improve the concentricity of the interior surface, and applying a coating of material on the inner surface of the tubular member using a high conductivity anode.

[0021] In accordance with a further aspect of the invention, the voltage drop along the anode is preferably between about 0.1 volt and about 0.25 volts. The anode may include, for

STM 245865 1 Express Mail No. EV 155 278 366 US example, platinum coated copper. The coating of material preferably has a thickness between about 0.00075 inches and about 0.0013 inches.

[0022] In further accordance with the invention, a metallic tubular member is provided defining a bore therethrough and an interior cylindrical surface within the bore, wherein the interior cylindrical surface includes a coating disposed thereon, and wherein the coating has a mean roughness between about 8 to about 10 microinches, and the coating has an average variation in thickness between about 0.00015 inches and about 0.00025 inches. [0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the invention. Together with the description, the drawings serve to explain the principles of the invention.

[0011] Fig. l(A) is a schematic view of electroplated coating thickness variation resulting from substantial electrical resistance of an anode.

[0012] Fig. l(B) is a schematic view of a plating fixture that may be used to coat the inner surface of a tubular member.

[0013] Fig. 2 is a schematic view of uniform thickness plating using a moving anode.

[0014] Fig. 3 is a schematic showing the effect of using intermittent conventional clamps during manufacturing processes on hard coating thickness of a tubular member. [0015] Fig. 4 is a schematic view of a pressurized bladder clamp employed in accordance with an embodiment of the invention.

[0016] Fig. 5 is an isometric view of a burnishing device employed in accordance with an embodiment of the invention.

[0017] Fig. 6 is a schematic view of a polishing device employed in accordance with an embodiment of the invention.

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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0017] Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Innovative and synergistic processes are disclosed herein, as well as the products made by these processes. These processes yield materials, such as tubular materials having a hard coating disposed therein with less expense and effort in comparison with the prior art techniques described above.

[0018] The processes described herein may be used on any suitable material. The processes disclosed herein are particularly advantageous for providing hollow tubular members with an inner hard coating wherein the tubular members have a generally round cross section. The present invention is also particularly applicable to tubular members having relatively thin walls, such as those having a wall thickness in the range for example of about 0.050 inches to 0.150 inches, preferably about 0.080 inches.

[0019] In accordance with a preferred embodiment of the invention, the process includes a plurality of steps.

[0020] In accordance with a first step, one or more relatively short tubular members are provided for processing.

[0021] For purposes of illustration and not limitation, as embodied herein, a preferred embodiment of a method carried out in accordance with the invention begins by providing one or more tubes of a suitable metallic material of relatively short length, such as between about 12 and about 36 inches in length in any desired increment, in contrast with known techniques that begin by using longer "multiple-length" tubes that are later divided into shorter lengths after processing. Any suitable diameter tubes may be processed in accordance with the teachings herein. Preferred diameters include, for example, from about one inch to about two inches, even more preferably tube diameters from about 36 mm to about 46 mm. Each tube is processed individually using the subject method at a reduced cost because of further novel processing described herein that provides, among other things, honing and roller burnishing prior to hard coating as described below. By refining the surface geometry of the interior of the tubular member prior to hard coating, it is possible to achieve a near net thickness precision hard coating (such as chromium plating). Moreover, this also facilitates simplified finishing of the individual tubes, as opposed to needing to remove large amounts of hard coating from inside the tubular member, a labor and time intensive process typical of prior art techniques.

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[0022] In accordance with a further step of the method, the relatively short tubular member is subjected to a radially inward substantially uniform clamping force along substantially its entire length.

[0023] For purposes of illustration and not limitation, as embodied herein, a preferred embodiment of a method carried out in accordance with the invention includes applying a clamp 20 capable of applying a substantially uniform compressive force to the tube 10. In accordance with a preferred embodiment, a clamping device 20 employing a pressurized bladder is utilized as depicted in Fig. 4. The clamps 20 provided in accordance with the subject invention may be provided in lengths between about five inches to about forty inches in any suitable length increment, such as inches or fractions of an inch. [0024] In operation, in accordance with a preferred embodiment, the entire length of tube 10 is clamped using a relatively high length to diameter ratio pressurized bladder clamp 20 as depicted in Fig. 4. Such a pressurized bladder clamp may be relatively long, having a clamping length between about thirty inches and about forty inches. While technically feasible, the inner tube 22 of clamp 20 becomes prohibitively expensive for extremely long clamping applications. Advantageously, unlike localized mechanical clamping, the pressurized bladder clamp 20 clamps thin-wall tube 10 substantially uniformly throughout its entire length and eliminates any clamping pressure-induced non-concentricity and non- uniformity. Preventing such elastic deformation results in a more uniform coating thickness, as described below.

[0025] The pressurized bladder clamp 20 includes a polymeric (e.g., polyurethane or similar polymeric material) inner tube 22 of appropriate thickness. As depicted, the inner tube 22 may be sealed to a metallic outer casing 24 forming an annular cavity 26 between the two. By pressurizing the annular cavity 26, using a suitable fluid such as a liquid or air or other suitable gas, the inner tube 22 compresses a split metallic sleeve 28 which in turn uniformly clamps the thin walled tube 10 as depicted in Fig. 4. Accordingly, the thin-wall tube 10 is firmly secured under substantially uniform pressure during subsequent process steps described below. As will be appreciated by those of skill in the art, higher clamping pressures may be applied using clamp 20 for relatively higher material removal rates during subsequent process steps (e.g., honing). Any suitable pressure ranges may be applied inside of cavity 26. In accordance with a first embodiment, the fluid pressure inside of cavity 26 may be between about 50 psi to about 100 psi, more preferably between about 60 psi to about 80 psi. As will be recognized by one of skill in the art, these are gage pressures.

STM 245865.1 Express Mail No. EV 155 278 366 US

[0026] In accordance with still a further step of the method, the tubular member is refined, for example, by way of honing along its interior to prepare it for further process steps, such as burnishing and/or hard plating.

[0027] For purposes of illustration and not limitation, as embodied herein, a preferred embodiment of a method carried out in accordance with the invention includes honing tubular member 10 while it resides in clamp 20. By honing tubular member 10 while it is confined in clamp 20, it is possible to create a tubular member 10 of enhanced concentricity and surface finish prior to hard plating. This may be practiced, for example, by providing tubular member 10 with a slightly smaller (e.g. by about -0.02") inside diameter and honing the inside surface 12 of tubular member 10 to the desired diameter, thus providing enhanced concentricity. Because of the higher uniform gripping pressure of the bladder clamp 20, the inner surface 12 of tubular member 10 may be honed at a relatively high material removal rate to reduce machining time, and hence, cost. It should be noted that relatively high machining speeds (e.g., about 600 RPM to about 800 RPM, but any other suitable machine speed may be used) and relatively high material removal rates (e.g., removal of a thickness of about 0.006 inches to about 0.010 inches of material in about a 50 second period along the length of the entire tubular member 10) can be practiced in accordance with the present invention. Generally, in prior art systems, honing of thin-wall tubular members cannot be achieved with use of conventional mechanical clamping devices without introducing non concentricity into tubular member 10, which results in a non-uniform inner diameter. The removal of a small amount (such as about 0.004" - about 0.008") of material from the inner surface 12 of tubular member 10 prior to applying a hard coating therein facilitates removal of surface imperfections from surface 12 to yield an optimum surface finish. For example, a desired mean roughness ("Ra") of about 5 to 10 micro-inches after honing and prior to burnishing (if desired), can result in an optimum surface finish. [0028] In accordance with yet a further step of the method, a burnishing step may be performed on the tubular member prior to hard coating.

[0029] For purposes of illustration and not limitation, as embodied herein, a preferred embodiment of a method carried out in accordance with the invention may include a refining operation such as burnishing (instead of or after honing). In accordance with a preferred embodiment, the burnishing may be roller burnishing. Roller burnishing of inner surface 12 of tubular member 10 helps provide an optimum surface finish of surface 12 prior to applying a hard coating thereto. Roller burnishing may be accomplished, for example,

STM ₂45865.1 O Express Mail No. EV 155 278 366 US using a roller burnishing tool similar to the one illustrated in Fig. 5, which is commercially available as Model No. R-Ol 812 from Cogsdill Tool Products, Inc. of Camden, South Carolina, USA. Roller burnishing the inner surface 12 of tubular member 10 may further reduce the mean roughness (Ra) from about 5 to about 10 micro-inches to about 3 to about 4 micro-inches. Moreover, roller burnishing may improve the overall concentricity of tubular member 10 and remove the appearance of honing lines. As such, depending on the particular end use intended for tubular member 10, this step may be desirable. The burnishing step may be optional, particularly when used in conjunction with a multiple step (e.g., three step) honing process prior to hard coating. However, burnishing is generally preferable in association with various embodiments of the invention.

[0030] Multiple step honing generally involves honing with initially lower (i.e., rougher) stone grits to remove material quickly, followed by successively higher (i.e., finer) stone grits to achieve smoother, scratch-free desirable surface finish at the desired dimension. Abrasive material can be made, for example, from diamond, vitrified stones, silicon carbide or aluminum oxide, among other materials. Vitrified stone material is generally preferred. [0031] Achieving an optimum, scratch-free surface finish prior to hard coating is particularly advantageous because once tubular member is hard coated, removing surface imperfections of the hard coating is much harder and time consuming than processing the base material. This adds undesired labor, time and expense to the process. [0032] In accordance with still a further step of the method, a coating of hard material is deposited on the inner surface of the tubular member. [0033] For purposes of illustration and not limitation, as embodied herein, a preferred embodiment of a method carried out in accordance with the invention may include depositing a hard coating on inner surface 12 of tubular member 10 using an electroplating process. Preferably, the electroplating process includes precision high deposition rate electroplating.

[0034] Precision high deposition rate electroplating is preferably accomplished by using a high conductivity anode. For example, chromium plating rates of about 0.001" to about 0.0015" per hour are achievable compared with about 0.0003" to about 0.0005" per hour using traveling anode techniques. A preferred anode may be constructed using platinized copper. Such material includes a copper core with a thin platinum plating to prevent reactivity of the copper core with the electroplating bath. Suitable anode material may be obtained, for example, from Anomet Products (Shrewsbury, MA, USA, exemplary

STM ₂45865 1 Q Express Mail No. EV 155278 366 US product name: Anomet 40). Using such a material for an anode permits high rate electrodeposition of material on tubular member 10. Preferably, the anode has a length that substantially corresponds to the entire length of tubular member 10. Because of the extremely low resistivity of the anode material in such a process, such as platinized copper, the voltage drop (IR) along the anode is minimized (e.g., to about 0.1 to 0.25 volts) as compared with a relatively long tubular member (for which voltage drops could be about 1-3 volts) to assure a substantially uniform thickness coating along the length of tubular member 10 (e.g., thicknesses from about 0.00075 inches to about 0.0013 inches thick). [0035] Moreover, by plating a relatively short tube instead of a multiple length tube as in prior art techniques, it is possible to mask tubular member 10 at selected places, such as at tube ends 14, 16 where additional features could be machined on the bare base metal without machining through the hard coating. Prior art processes employing, for example, long tubes with a moving anode do not offer this selective masking capability. [0036] A variety of hard coatings may be deposited on tubular member 10 in accordance with the invention, including, for example, chromium, Co-P alloy coatings as well as Co-P electrocomposite coatings incorporating tribological particles, such as those described in copending U.S. Patent Application Serial No. 11/510,417, filed August 25, 2006 and published on July 26, 2007 as US20070170068(Al), which is incorporated by reference herein in its entirety. When applying such a nanocomposite coating including tribological particles, in the context of the present disclosure, it is presently preferred to use a cobalt- plated consumable anode, although a platinized copper core inert anode may also be used. A heat treatment step of this nanocomposite coating may also be carried out, preferably at temperatures from about 180⁰C to about 240⁰C for a time period from about 30 minutes to about 120 minutes in any desired increment.

[0037] In further accordance with the method, the hard coated tubular member may undergo one or more finishing steps.

[0038] For purposes of illustration and not limitation, as embodied herein, a preferred embodiment of a method carried out in accordance with the invention may include one or more honing or burnishing steps, as desired. Specifically, because the tubular member 10 was honed and/or burnished prior to hard coating, coated tubular member 10 already possesses enhanced concentricity and an optimized surface finish before electroplating. Moreover, by providing a precision near-net thickness coating by way of a high conductivity anode, the need for over plating and expensive multiple stage honing to achieve ID tube

STM ₂45865 1 \ Q Express Mail No. EV 155278 366 US surface finish and dimensional characteristics typical of prior art techniques is eliminated. Accordingly, while additional steps could be practiced, the inner surface 12 of the tubular member can be finish honed or polished in a single operation. This is particularly advantageous since the material of the hard coating is typically much harder to machine than the base material of tubular member 10.

[0039] While a variety of polishing techniques may optionally be employed, a preferred polishing technique includes disposing an radially outwardly expandable cylindrical mandrel inside of the tubular member 10, wherein the cylindrical surface of the mandrel includes abrasive material disposed thereon, such as Emory cloth or sandpaper including silicon carbide or aluminum oxide abrasive material. The radial dimension of the cylinder can be expanded by any suitable means. In accordance with a preferred embodiment, the cylindrical mandrel includes a resilient outer surface that may be expanded by application of fluid pressure inside the cylinder. An exemplary embodiment of such a mandrel 200 is depicted in Fig. 6. Mandrel 200 includes a generally cylindrical body 210 having a first end 212, a second end 214 and defining a generally hollow interior 216 therein for receiving a pressurizing fluid. Body 210 further includes a perforate frame 218 defining openings 219 therein for supporting an outer flexible skin 215 attached to the frame 218. [0040] As depicted, cylindrical body 210 of mandrel 200 is inflated by way of a pressurized fluid that can be injected through an elongate tubular member 220 having a first end 222 and a second end 224, such as a rigid valve stem. The connection from frame 218 to member 220 is preferably rigid, such that second end 224 may be held in a stationary manner, such as in a tool holder of a lathe, and tubular member 10 can be rotated about mandrel 200 as mandrel 200 is moved back and forth along the length of tubular member to perform the polishing operation. Abrasive material 250 (e.g., sandpaper or Emory cloth) is disposed about mandrel 200 to perform the polishing. Pressurized fluid can be supplied in the form of compressed air, for example, at pressures such as about 10 psig - 100 psig, preferably about 30-50 psig. As will be appreciated by those of skill in the art, other pressurizing fluids and pressures may also be used, as appropriate.

[0041] Embodiments of the novel low-cost manufacturing process embodied herein results from an innovative synergy of manufacturing steps where each step is facilitated because of the preceding step. Specifically, the processing of individual tubes instead of much longer multiple length tubes and then dividing them into individual tubes solves a number of problems inherent in prior art techniques. Practicing this technique on multiple

STM ₂45865.1 \ \ Express Mail No. EV 155 278 366 US shorter tubes instead of a single longer tube is counterintuitive, since one of ordinary skill in the art would perceive this teaching as one that would be cumbersome and labor intensive. In actuality, the opposite is true.

[0042] Moreover, the high speed/high material removal rate honing techniques coupled with burnishing prior to plating rather than over plating and multiple stage honing provides for an optimum surface preparation for plating that minimizes post plating operations. Use of a relatively high length to diameter pressurized bladder clamping substantially the entire tube length instead of localized non-uniform mechanical clamping minimizes elastic deformation of the tubular member, which results in less complications during subsequent manufacturing steps. Also, near-net thickness plating using a high conductivity anode covering substantially the entire tube length provides a substantially uniform coating along the length of tubular member 10. The need for over plating is eliminated because of prior honing of a tubular member having enhanced concentricity. Substantially higher plating rates can be achieved compared to that of prior art techniques such as the slow moving anode process. Light finish honing or polishing instead of expensive two stage honing after hard coating applications may also be realized using the techniques described herein.

[0043] The variation of plating thickness in exemplary embodiments of tubular members 10 are approximately 0.00015" to 0.00025" using methods disclosed herein. Since prior art techniques generally apply thicker coating deposits (followed by honing to finish size) there is more thickness variation after plating using prior art techniques than the precision plating technique described herein.

[0044] The methods and systems of the present invention, as described above and shown in the drawings, provide a method and resulting product with superior properties. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention include modifications and variations that are within the scope of the subject disclosure and equivalents.

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Claims

Express Mail No. EV 155 278 366 USCLAIMS What is claimed is:

1. A manufacturing process comprising: a) providing a metallic tubular member for processing; b) subjecting the metallic tubular member to a substantially uniform radially inward clamping force along substantially its entire length; c) refining the interior surface of the tubular member to improve the surface finish and concentricity of the interior surface; and d) applying a coating of material on the inner surface of the tubular member.

2. The process of Claim 1, wherein the coating of material is harder than the metallic tubular member.

3. The process of Claim 1, wherein the tubular member has a wall thickness between about 0.050 inches and about 0.150 inches.

4. The process of Claim 1, wherein the tubular member has a wall thickness of about 0.80 inches.

5. The process of Claim 1, wherein the tubular member is between about 12 inches in length and about 36 inches in length.

6. The process of Claim 1, wherein the refining step includes at least one of a honing process and a burnishing process.

7. The process of Claim 1, wherein the clamping force is applied to the tubular member using a clamp that is actuated by pressurizing a fluid in a reservoir.

8. The process of Claim 7, wherein the fluid is pressurized to a pressure between about 50 psi and about 100 psi.

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9. The process of Claim 7, wherein the fluid is pressurized to a pressure between about 60 psi and about 80 psi.

10. The process of Claim 7, wherein the clamp is between about 5 inches in length and about 40 inches in length.

11. The process of Claim 6, wherein the inside diameter is enlarged by up to about 0.02 inches during honing.

12. The process of Claim 1, wherein the inside diameter of the tubular member is increased by between about 0.012 inches and about 0.20 inches in about a 50 second period during the refining step.

13. The process of Claim 6, wherein honing results in an interior tubular surface having a mean roughness between about 5 and about 10 microinches.

14. The process of Claim 6, wherein honing includes a multiple-step honing process.

15. The process of Claim 14, wherein the multiple-step honing process is a three-step honing process.

16. The process of Claim 6, wherein the interior surface of the tubular member is burnished to improve the concentricity of the interior surface after honing and prior to the coating step.

17. The process of Claim 16, wherein burnishing is carried out by way of roller burnishing.

18. The process of Claim 6, wherein honing results in an interior tubular surface having a mean roughness between about 3 to about 4 microinches.

19. The process of Claim 16, wherein burnishing removes substantially all marks on the interior surface of the tubular member created during honing.

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20. The process of Claim 1, wherein the coating is applied using an electroplating process.

21. The process of Claim 20, wherein, the electroplating process includes high deposition rate electroplating.

22. The process of Claim 20, wherein the electroplating process is performed using an anode having a platinum-coated copper core.

23. The process of Claim 20, wherein the anode has a voltage drop along its length that is sufficiently low to facilitate formation of an electrodeposited coating on the tubular member having a substantially uniform thickness.

24. The process of Claim 1, further comprising masking the tubular member in at least one location prior to the coating step to prevent the masked location from being coated.

25. The process of Claim 24, wherein the tubular member is masked proximate the ends of the tubular member.

26. The process of Claim 1, wherein the coating includes at least one of a chromium material, a Co-P material and a Co-P electrocomposite coating.

27. The process of Claim 1, further comprising at least one finishing step after the coating step.

28. The process of Claim 27, wherein the at least one finishing step includes one or more honing, polishing or burnishing steps.

29. The process of Claim 28, wherein the polishing step includes polishing the inside of the tubular member with a radially adjustable cylindrical mandrel including abrasive material disposed on its surface.

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30. A manufacturing process comprising: a) providing a metallic tubular member; b) subjecting the metallic tubular member to a substantially uniform radially inward clamping force along substantially its entire length; c) refining the interior surface of the tubular member to improve the concentricity of the interior surface; and d) applying a coating of material on the inner surface of the tubular member using a high conductivity anode.

31. The process of Claim 30, wherein the voltage drop along the anode is between about 0.1 volt and about 0.25 volts.

32. The process of Claim 30, wherein the anode includes platinum coated copper.

33. The process of Claim 30, wherein the coating of material has a thickness between about 0.00075 inches and about 0.0013 inches.

34. A metallic tubular member defining a bore therethrough and an interior cylindrical surface within the bore, wherein the interior cylindrical surface includes a coating disposed thereon, and wherein the coating has a mean roughness between about 8 to about 10 microinches, and the coating has an average variation in thickness between about 0.00015 inches and about 0.00025 inches.

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