JPH05287319A - Hot isostatic pressing method - Google Patents

Abstract

PURPOSE:To inexpensively and easily produce a material with the base material provided with corrosion resistance, high-temp. corrosion resistance, oxidation and wear resistance by a surface coat. CONSTITUTION:The inner surface of a hollow metallic material 1 is coated with the powder 2 of another metal by HIP and drawn by hot extrusion to produce a double tube. In this case, a corrugated tube is used for a capsule to be filled with the powder in HIP, hence the capsule is not broken in HIP, and a uniform HIP layer is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot isostatic pressing method, and more particularly to a method for coating the inner surface of a metal pipe with a layer having characteristics such as corrosion resistance, high temperature corrosion resistance, oxidation resistance and wear resistance. It is about.

[0002]

2. Description of the Related Art In recent years, materials have come to be used in an increasingly severe environment due to industrial progress and technological development. For example, in energy resource development, petroleum and natural gas (so-called sour oil and sour gas) containing a large amount of hydrogen sulfide and carbon dioxide in the production fluid have been developed, but materials for oil well pipes and line pipes used for the development As low-alloy steel causes corrosion and cracking, Hastelloy C-2
Nickel alloys such as 76 and Inconel 625 (both are trade names) have already been used. However, the great disadvantage is that these alloys are very expensive. Therefore, it has been considered to use so-called clad steel in which these alloys are used as a laminated material only on the surface of the structural material and the strength is secured by the underlying metal (for example, low alloy steel).

Various manufacturing methods have been established or proposed for the clad steel as a seamless pipe or a welded pipe when the shape thereof is a tube, and as a rolled plate when the shape is a plate. However, in addition to the drawback that the manufacturing process is complicated and the yield is poor, Hastelloy C-276 and Inconel 6
Clad steel made of a nickel alloy such as 25 as a composite material, in particular, a clad steel pipe is very difficult to manufacture and has not yet been put to practical use. According to the study of the present inventors, the reason is that the deformation resistance during hot working of these alloys is significantly larger than that of the low alloy steel or carbon steel as the base material,
It is conceivable that it is difficult to join the laminated material and the base material because they cannot be uniformly processed by a normal manufacturing process such as hot rolling and both metals are independently deformed.

On the other hand, the spindle portion of the valve, the sliding portion such as the piston and the cylinder of the reciprocating pump, or the member such as the pipe for slurry transportation is required to have wear resistance, and therefore, for example, Stellite alloy (trade name) is used. ,
It is used after being built up or sprayed. Further, pressure vessels and steel pipes used at high temperatures are coated with an oxidation resistant material such as a Ni-Cr alloy, a Ni-Cr-Al-Y alloy or a Co-Cr-Al-Y alloy by overlaying or spraying. There are cases where However, these are all very expensive because they are built up or sprayed onto the final product. In addition, it has a drawback that it cannot cover a narrow portion such as the inner surface of a small diameter pipe.

By the way, the hot isostatic pressing method is a well-known technique in the past, and a cladding product utilizing this method has been proposed. For example, JP-A-61-2
Japanese Patent No. 23106 discloses a method for efficiently producing a high alloy clad product by heating the high alloy powder to a temperature above the solidus temperature of the powder and pressurizing the gas. However, all of the previously reported or proposed methods for producing clad products using the hot isostatic pressing method, such as this method, cover the final product, resulting in high cost, large-scale products, and long-life products. Measure (for example, 12m length)
However, it has a drawback that it cannot be manufactured.

Further, Japanese Patent Laid-Open Nos. 61-190007 and 61-190008 each disclose a capsule formed of a thick malleable metal cylinder and a thin metal cylinder having a diameter different from that of the malleable metal cylinder. Powder is filled and sealed inside, and this is pressed by cold isostatic pressure to compress the powder into a billet, which is hot extruded, and the concentric cylindrical inner and outer two In a container of rubber or similar substance having a heavy wall, a malleable metal cylindrical material is housed in close contact with one container wall, and a powder material is filled between the other container wall and the cylindrical material. It is disclosed that a material is taken out from the container and is hot extruded as a billet. Also by these methods, when a coating layer of a material having a large deformation resistance such as a nickel alloy such as Hastelloy C-276 or Inconel 625 described above is formed and hot-worked, the adhesion to the base material is weak and the base material is weakly adhered. The difficulties of peeling and cracking of the coating layer cannot be eliminated.

On the other hand, in Japanese Patent Laid-Open No. 64-202, a hot isostatic pressure is applied to the surface of a metal material by applying a gas pressure of a powder of another metal at a temperature below the solidus temperature of the other metal. A method of forming a coating layer by pressing (HIP), followed by hot working and stretching, a method of forming a coating layer and then subjecting to solution treatment and hot working, and soaking. There has been proposed a method of performing hot working and stretching immediately after the addition of the above.

However, in this method, particularly when the inner surface of the hollow metal is coated with various metals, hot working is carried out and stretched to produce a steel pipe whose inner surface is coated with another metal, the inner diameter of the hollow metal is increased. The smaller is the deformation amount that the capsule of the powder-filled part undergoes during hot isostatic pressing becomes extremely large on the stretching side, so that the capsule often breaks during hot isostatic pressing, and coating cannot be performed sufficiently. There was a problem.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the problems of these prior arts, and is a metal tube provided with characteristics such as corrosion resistance, high temperature corrosion resistance, oxidation resistance, and wear resistance on its inner surface. The present invention provides a method for easily and inexpensively manufacturing.

[0010]

The inventors of the present invention have conducted various experiments and studies in order to achieve the above-mentioned object, and as a result, the extremely large deformation on the stretched side which the capsule undergoes during hot hydrostatic pressure is It has been found that this can be solved by using a material that allows a large deformation in the stretching direction, that is, a corrugated tube, as a material.

The present invention has been made on the basis of the above findings, and the gist of the invention is that the inner surface of a hollow metal material is
In a method of forming a powder of another metal as a coating layer by a hot isostatic press applying a gas pressure below the solidus temperature of the other metal, using a corrugated tube as a capsule material of the powder filling portion. It is a feature of the hot isostatic pressing method.

Here, the kinds of the hollow metal material as the "base material" and the other kind of metal as the "composite material" are not particularly limited, and examples of the metal material include carbon steel, low alloy steel and stainless steel. Examples include steel, nickel and nickel alloys, cobalt and cobalt alloys, titanium and titanium alloys, and the like. On the other hand, as the other metal, corrosion resistance, high temperature corrosion resistance, oxidation resistance, wear resistance, etc. may be selected according to the required function, for example, Hastelloy,
Stellite, Ni-Cr alloy, stainless steel, Fe-based superalloy, nickel and nickel alloys, cobalt and cobalt alloys, titanium and titanium alloys, etc. may be mentioned.

[0013]

The present invention will be described in detail below. In the present invention, the coating layer of another kind of metal is formed on the inner surface of the hollow metal material by the hot isostatic pressing method. However, the other kind of metal is powder and the metal material 1 is formed in the manner shown in FIG. And another kind of metal powder 2 are filled and sealed in a capsule, and then hot isostatic pressing is performed. At this time, a corrugated tube is used as the capsule material at the position 3 in FIG. Since the filling degree of ordinary powder is limited to 70%, for example, when a coating layer having a wall thickness of 20 mm is to be formed on the inner surface of a hollow metal material having an inner diameter of 90 mm, the outer diameter of the capsule is 10 mm. At this time, the outer diameter of the capsule after hot isostatic pressing was 50 mm, which was actually 5 mm.
Although the amount of pipe expansion is doubled, if a corrugated tube is used as the capsule material, it is possible to withstand a pipe expansion amount of 5 times.
Hot isostatic pressing can be performed without problems.

In the present invention, various conditions (for example, temperature, pressure, etc.) at the time of hot isostatic pressing can be set arbitrarily. Further, the material after hot isostatic pressing may be used as it is, or may be stretched by, for example, hot extrusion. Regarding the shape after stretching, it can be applied to various shapes such as a square tube in addition to an ordinary tube.

[0015]

EXAMPLES Examples of the present invention will be described below. A hot isostatic pressing process was performed using the hollow metal material and the metal powder having the dimensions and materials shown in Table 1. Here, No. 1 to
No. 4 of the present invention, No. 4 5-8 is a comparative example. In the comparative example, an ordinary tube conventionally used as a capsule material was used. The results are also shown in Table 1.

In Table 1, No. which is a comparative example. In all of Nos. 5 to 8, the capsules broke during hot isostatic pressing. On the other hand, Example No. manufactured according to the present invention was used. Each of the materials 1 to 4 could be hot isostatically pressed without any problems, and it was confirmed from the microscopic observation results that the coating layer had no pores and a uniform and good bonding interface was obtained.

[0017]

[Table 1]

[0018]

As described above, according to the hot isostatic pressing method of the present invention, it is possible to produce a surface-coated metal having excellent properties, which is extremely significant in contributing to the development of industry.

[Brief description of drawings]

FIG. 1 is a diagram showing a filling procedure in a hot isostatic press for forming a coating layer of another metal on the inner surface of a hollow metal.

[Explanation of symbols]

 1 Metal material 2 Other metal powder 3 Capsule 4 Caps of capsule

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical indication location B30B 11/00 E 7128-4E H 7128-4E (72) Inventor Hiroyuki Ogawa 20 Shintomi, Futtsu City, Chiba Prefecture -1 Inside Nippon Steel Co., Ltd. Technology Development Division

Claims (1)

[Claims] 1. A method of forming a powder of another metal on the inner surface of a hollow metal material as a coating layer by a hot isostatic press applying a gas pressure at a temperature below the solidus temperature of the other metal as a coating layer. A hot isostatic pressing method, characterized in that a corrugated tube is used as a capsule material for some parts.