JP2003001401A - Manufacturing method of barrel having horizontal hole, and the barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a barrel manufacturing method in which a lining layer is simultaneously formed on an inner circumferential surface of a barrel and an inner circumferential surface of a horizontal hole, and the barrel having the horizontal hole with excellent productivity can be manufactured at a low cost. SOLUTION: An intermediate member 12 formed of steel and having a barrel hole 13 so as to form a cast iron barrel base material 10 with the horizontal hole 14 opened in its side surface is cast in an inside diameter part of the barrel base material 10, and the lining layer 16 formed of Ni-B-Si-Mo corrosion- resistant and wear-resistant alloy is simultaneously formed on the inner circumferential surface of the intermediate member 12 and the inner circumferential surface of the horizontal hole 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a barrel used in an extrusion molding machine or an injection molding machine and the barrel, and more particularly, to a horizontal hole used for charging materials.
The present invention relates to a method of manufacturing a barrel and an inner peripheral surface that require corrosion resistance and wear resistance.

[0002]

2. Description of the Related Art A barrel for an extrusion molding machine or an injection molding machine is a hollow-shaped component in which a mating component such as a screw slides or rotates. Therefore, when kneading and injecting a resin containing hard particles. Friction occurs on the inner peripheral surface, which is a problem. In addition, there is a problem that the resin is damaged by the corrosive gas generated from the molten resin. As a countermeasure, a hard alloy layer having excellent corrosion resistance and wear resistance has been conventionally lined (coated) on the inner peripheral surface of the barrel.

The method of lining a hard alloy layer having excellent corrosion resistance and wear resistance on the inner peripheral surface of the barrel includes shrink fitting, thermal spraying,
There are many things such as vapor phase film formation and plating, and most of the hard materials that have been conventionally used as the material for the alloy layer to be lined are manufactured by the powder metallurgy method and the hot isostatic pressing method. There are many things.

Some barrels have lateral holes formed on their side surfaces for the purpose of introducing raw materials and degassing. Unlike the inner peripheral surface of the barrel, there is no friction due to the screw on the inner peripheral surface of the horizontal hole for feeding the raw material, but abrasion resistance is required due to the influence of the glass fibers and hard particles added to the raw material, and degassing The horizontal holes for use are required to have corrosion resistance against the influence of corrosive gas generated from the raw material resin. Generally, the inner peripheral surface of the lateral hole is plated, but the requirements for corrosion resistance and wear resistance have not been sufficiently satisfied due to the influence of small film thickness and fine cracks on the surface. Therefore, regarding the technology of lining the corrosion-resistant and wear-resistant alloy layer on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole in the process of manufacturing the barrel having the lateral hole,
The following technologies have been proposed.

The barrel material is processed from a forged base material, and a lining layer is formed on the inner peripheral surface of the barrel by a hot isostatic pressing method or the like, and then mechanical processing is performed to form a lining layer at a location where a lateral hole is formed. What to join.

By processing the material of the barrel from the forged base material,
A lining layer is simultaneously formed on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole by the hot isostatic pressing method.

A barrel material is produced from a cast base material, and a lining layer is formed on the inner peripheral surface of the barrel by thermal spraying and sintering.
Machined after drilling the side hole, the inner surface of the side hole is plated.

[0008]

In the above-mentioned conventional technique, it is necessary to remove a part of the lining layer formed on the inner peripheral surface of the barrel by a special process in order to open a hole communicating with the lateral hole. In most cases, the lining layer formed on the inner surface of the barrel is a special alloy with excellent wear resistance and cannot be removed by normal machining, so special processing such as electrical discharge machining must be used. High cost.
Also, it is necessary to consider the costs for manufacturing and joining the insert pieces.

The above-mentioned conventional technique has an advantage that a lining layer can be simultaneously formed on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole. However, in order to form the lining layer, the filling space of the alloy powder is created in advance by a welded structure of steel material, the welded structure is filled with the alloy powder, and further deaeration and sealing are performed, followed by hot working. It is treated by the hydrostatic pressure method. After the treatment, the welded structure needs to be removed by machining. As described above, the process is complicated and the hot isostatic pressing equipment is required, resulting in high cost.

On the other hand, in the above-mentioned prior art, since the material of the barrel is processed by casting instead of forging, it is possible to improve the productivity and reduce the cost for manufacturing the base material. Due to the complexity of the usage, the barrel has various shapes and complicated shapes, and since the number of products produced is large,
In that respect, casting is suitable for manufacturing such a barrel material.

However, in the case of a cast barrel material, when the hard material is lined on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole, the graphite and the hard alloy contained in the cast iron as the base material of the barrel material react during the joining process. As a result, poor bonding may occur. In addition, when the hard material is lined on the cast iron base material, the melting point of the hard material is as high as 1100 ° C. or higher, which causes a problem that the cast iron base material is deteriorated and deformed.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to simultaneously form a lining layer on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole, which is excellent in productivity and can be manufactured at low cost. It is to provide a method for manufacturing a barrel having a lateral hole and the barrel.

[0013]

In order to achieve the above-mentioned object, a method of manufacturing a barrel according to the present invention is a steel material for forming a barrel hole in order to form a cast iron barrel base material having a lateral hole open to the side surface. A step of casting an intermediate member consisting of the inner peripheral part of the barrel base material, and a lining layer composed of a Ni-B-Si-Mo-based corrosion-resistant wear-resistant alloy on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole at the same time. And a lining step of forming.

By using a cast iron base material as the barrel base material, it is possible to simultaneously cast a plurality of base materials, which is advantageous in reducing the cost of the base material. However, depending on the type of corrosion-resistant and wear-resistant alloy to be lined, the base material made of cast iron is used. Defects may occur at the boundary when directly joined with. The cause is considered to be the influence of graphite contained in cast iron. As graphite diffuses into the lining layer, voids and coarse carbide layers are formed at the boundaries, which reduce the strength.

In the present invention, in order to eliminate the influence of graphite in the cast iron base material, the intermediate member forming the barrel inner peripheral surface for lining the corrosion-resistant and wear-resistant alloy is cast around the barrel base material, and the inner peripheral surface of the intermediate member is cast. By lining the surface with a corrosion-resistant and wear-resistant alloy, the cast iron base material and the wear-resistant alloy are not directly joined.

On the other hand, in a lateral hole for venting gas, since the joining strength of the lining layer does not need to be as high as that of the inner peripheral surface of the barrel, it is not necessary to wrap the intermediate member in the lateral hole, but this lining layer is used. It is necessary to select a corrosion-resistant and wear-resistant alloy that can be firmly joined to cast iron.

From this point of view, the corrosion-resistant and wear-resistant alloy used as the material for the lining layer is a Ni-B-Si-Mo alloy, and preferably, its composition is B: 0.6 to about in weight%.
3.2%, Si: 0.5-8%, Mo: 5-37%,
C: 0.01 to 1% is contained, and the balance is preferably a corrosion and wear resistant alloy having a composition of Ni and inevitable impurities.

Here, the reason for limiting the composition ratio of the above corrosion-resistant and wear-resistant alloy is as follows. First, B lowers the sintering temperature and forms borides with Ni and Mo to enhance the corrosion resistance and wear resistance of the alloy. If the B content is high or low, the transverse rupture strength is reduced, so the content was made 0.6 to 3.2%. The B content is more preferably 1.0 to 3.1%.

Si, like B, lowers the sintering temperature. The sintering temperature decreases as the Si content increases, but if it exceeds 8%, the transverse rupture strength decreases sharply. Even when the amount of Si is small, the transverse rupture strength is lowered and the sintering temperature is raised, so the lower limit is made 0.5%. Therefore, the Si content is set to 0.5 to 8%. The Si content is more preferably 2.5 to 7%.

Mo forms a boride with B, and has the effects of increasing the wear resistance and improving the corrosion resistance of the binder phase mainly composed of Ni. Further, it has the effect of making the crystal grains of the alloy finer and significantly increasing the strength and the transverse rupture strength. Such an effect occurs when Mo is 5%, and when it exceeds 40%, the transverse rupture strength decreases. This decrease in transverse rupture strength is considered to be because the sintering temperature becomes higher due to the increase in Mo, and as a result, the crystal grains become coarse due to the high temperature sintering. Therefore, the Mo content is 5 to 3
It was set to 7%. The Mo content is more preferably 15 to 32%.

The reason why the amount of C added is 0.01 to 0.1% is as follows. That is, when C is 0.01% or less, the effect of reducing the oxide film on the powder surface is small, and the addition amount is very small, so that it becomes difficult to control the C amount. Further, when C is 1% or more, a large amount of carbide is precipitated and the corrosion resistance and wear resistance characteristics of the alloy are changed. Therefore, the amount of C added is set to 0.01 to 1%.

It has been found that when a lining layer is formed from such a Ni-B-Si-Mo alloy, no voids or hard and brittle coarse carbide layer is formed at the joint boundary with the cast iron on the inner peripheral surface of the lateral hole. Obtained. Also, this alloy has a sintering temperature of 1
It is as low as 050 ° C. or lower, and the lining layer can be formed without degrading or deforming the cast iron base material.

The method for forming the lining layer can be selected from pressureless sintering bonding, pressureless bonding, thermal spraying-remelting, and brazing, and the heat treatment is performed in a vacuum furnace. By doing so, without using special equipment for carrying out hot isostatic pressing or hot pressing,
The running layer can be simultaneously formed on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole at a low cost. It is possible to reduce the cost by about half as compared with the conventional example of forming the lining layer by the hot isostatic pressing method.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a barrel having a lateral hole and a manufacturing method thereof according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a barrel for a twin-screw extruder manufactured by applying the manufacturing method of the present invention,
FIG. 1A is a view showing a vertical cross section of the barrel, and FIG. 1B is a view showing an end face of the barrel.

In FIG. 1, reference numeral 10 is a base material which constitutes the main body of the barrel. The base material 10 is formed by casting, and an intermediate member 12 made of a steel material is cast around the inner diameter portion of the base material 10.
A barrel-shaped barrel hole 13 is formed. Barrel hole 13
A screw (not shown), which serves to both knead and pump the resin, is inserted into the.

On the side surface of the base material 10, there is formed a horizontal hole 14 for introducing a raw material into a barrel from a hopper (not shown). The charged raw material is heated, melted, and kneaded in the barrel hole 13 while being pressure-fed forward by the screw, and is filled in the mold connected to the outlet.

Friction occurs between the rotating screw and the inner peripheral surface of the barrel, and when heated, it contacts the corrosive gas generated from the raw material resin and is worn. Therefore, a lining layer 16 made of a Ni-B-Si-Mo-based corrosion-resistant wear-resistant alloy having excellent wear resistance and corrosion resistance is formed on the inner peripheral surface of the intermediate member 12 corresponding to the inner peripheral surface of the barrel. . Also,
Lining layer 1 made of the same alloy on the inner peripheral surface of the lateral hole 14
6 is formed. Reference numeral 17 denotes a temperature control pipe that is cast in the base material 10.

The composition of this Ni-B-Si-Mo corrosion resistant wear resistant alloy is as follows: B: 3.1% by weight, Si: 4.6%, M
A material containing o: 20% and C: 0.01% with the balance being Ni and inevitable impurities was used.

Next, FIG. 2 shows a barrel for an injection molding machine manufactured by applying the manufacturing method of the present invention, and FIG.
FIG. 2 is a view showing a vertical cross section of the barrel, and FIG. 2B is a view showing an end face of the barrel.

Similarly, in the base material 20 of the barrel for the injection molding machine, a cylindrical intermediate member 22 made of a steel material is cast in the inner diameter portion, and a lateral hole 24 for introducing a raw material is formed on the side surface. ing. The intermediate member 22 forms a barrel hole 23 into which the screw is inserted, and the inner peripheral surface of the intermediate member 22 corresponding to the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole 24 are Ni-BS.
A lining layer 26 made of an i-Mo-based corrosion resistant wear resistant alloy is formed. The composition of this Ni-B-Si-Mo-based corrosion-resistant wear-resistant alloy is the same as that of the barrel shown in FIG.

FIG. 3 is a process drawing of the method for manufacturing the barrel. The process of FIG. 3 will be described in connection with the production of the barrel for the twin-screw extruder shown in FIG. First of all, the intermediate member 1
2 and the temperature control pipe 17 are processed to have a required size. For the intermediate member 12, for example, a steel material made of S35C is used. Next, the intermediate member 12 and the temperature control pipe 17 are incorporated into a mold together with the core, and the base material 10 is cast into a casting by casting the base material 10 as a whole. As the casting material used in this casting process, ductile cast iron (F
CD600) is preferred. When the intermediate member 12 is cast, the intermediate member 12 is cast only in the axial direction of the barrel, and the lateral hole 14 is formed by machining the base material 10 formed after the cast-in-hole casting.

The lining layer 16 has a barrel inner peripheral surface formed by the intermediate member 12 through the above steps and the lateral hole 1
Alloy powder of the above composition (particle size 40-150μ
m atomized powder) is sprayed. Then, the base material 10 is put into a vacuum furnace and heated at 1040 ° C. for 120 minutes to perform heat treatment for remelting the sprayed lining layer to make it dense. The thickness of the formed lining layer was 2.0 mm on the inner peripheral surface of the barrel and 1.1 mm on the inner peripheral surface of the lateral hole. The process of forming this lining layer 16 is the same as Ni-B-S.
Pressure-free sintering using i-Mo system corrosion resistant wear resistant alloy powder,
It is also possible to use pressureless diffusion bonding or brazing.

Finally, the barrel is cut and machined to final product dimensions.

Next, FIG. 4 is a metallurgical micrograph showing the boundary between the lining layer and the intermediate member (material S35C) formed under the above-mentioned conditions. According to this
The intermediate member and the lining layer were firmly metal-bonded together, and no coarsening of crystal grains was observed on the intermediate member side.

FIG. 5 shows the inner peripheral surface of the lateral hole (material F
It is a metallurgical micrograph which shows the boundary of (CD600) and a lining layer. Although the ductile cast iron and the lining alloy were in direct contact with each other on the inner surface of the lateral hole without the intermediate member, the ductile cast iron and the lining alloy layer were strongly metal-bonded. Further, as clearly shown in the photograph, although formation of fine carbide was confirmed, defects such as voids and coarsened carbide were not confirmed. The metal micrograph shown as FIG. 6 shows the boundary between the lining layer formed only by thermal spraying without remelting and the substrate, but in the case of thermal spraying only,
Since the lining layer becomes a porous layer, there is a concern that the alloy strength and the bonding strength with the base material may become insufficient. Therefore, as described above, it is preferable to re-melt and densify the lining layer. In this remelting, the sintering temperature of the corrosion-resistant and wear-resistant alloy used in the conventional barrel lining is 1
Since it can be performed at a temperature lower than 110 ° C., it is possible to prevent the base material from being deformed.

FIG. 7 shows the results of the transverse rupture strength test of the inner peripheral surface of the barrel, the lining layer on the inner peripheral surface of the lateral hole, and the alloy itself of the lining layer.

Further, the wear amount and the corrosion amount as a result of being used in the actual machine were compared with that of the barrel described as the prior art, and the wear amount was equal, but the corrosion amount of the lateral hole was about the same as that of the barrel. The life was more than doubled.

[0038]

As is apparent from the above description, according to the present invention, a lining layer having excellent corrosion resistance and abrasion resistance is simultaneously formed on the inner peripheral surface of the barrel and the inner peripheral surface of the lateral hole, which is excellent in productivity and low in productivity. Barrels with side holes can be manufactured at a cost.

[Brief description of drawings]

1 is a view showing a barrel for a twin-screw extruder manufactured by a manufacturing method of the present invention, FIG. 1 (a) is a longitudinal sectional view, FIG.
(B) is an end view.

FIG. 2 is a view showing a barrel of an injection molding machine manufactured by the manufacturing method of the present invention, FIG. 2 (a) is a longitudinal sectional view, and FIG. 2 (b).
Is an end view.

FIG. 3 is a process drawing of the method for manufacturing the barrel according to the embodiment of the present invention.

FIG. 4 is a metallurgical micrograph showing a boundary between an intermediate member and a lining layer.

FIG. 5 is a metallurgical micrograph showing a boundary between cast iron and a lining layer in a lateral hole.

FIG. 6 is a metallurgical micrograph showing a lining layer when the lining layer was not remelted in forming.

FIG. 7 is a view showing a result of a bending strength test of a lining layer.

[Explanation of symbols]

10 Base material 12 Intermediate member 13 barrel holes 14 Horizontal holes 16 lining layer 20 Base material 22 Intermediate member 23 barrel holes 24 side holes 26 Lining layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shuhei Homma             2068 Ooka, Numazu City, Shizuoka Prefecture Toshiba Machine Co., Ltd.             In the company F-term (reference) 4F207 AJ02 AJ09 KA01 KA17 KK14                       KL32 KL41                 4K031 AA02 AB08 CB23 FA02

Claims (4)

[Claims] 1. A step of casting an intermediate member made of a steel material for forming a barrel hole into an inner diameter portion of the barrel base material so as to form a cast iron barrel base material having a lateral hole open to a side surface, and the intermediate member. Ni at the same time on the inner peripheral surface of the
And a lining step of forming a lining layer made of a B-Si-Mo-based corrosion-resistant and wear-resistant alloy, and a method of manufacturing a barrel having a lateral hole. 2. The composition of the Ni-B-Si-Mo-based corrosion-resistant and wear-resistant alloy is B: 0.6 to 3.2% by weight, Si:
0.5-8%, Mo: 5-37%, C: 0.01-1%
2. The method for producing a barrel having a lateral hole according to claim 1, wherein the barrel contains a metal and the balance is Ni and inevitable impurities. 3. The lining step comprises pressureless sintering joining,
The method for manufacturing a barrel having a lateral hole according to claim 1 or 2, wherein the method is one of pressureless joining, spraying-remelting, and brazing. 4. A barrel having a lateral hole for a plastic molding machine, the lateral hole of which is formed on a side surface of the barrel. The intermediate member made of a steel material forming the barrel hole is formed of a cast iron barrel base material, and the inner peripheral surface of the intermediate member is formed. A lining layer made of a Ni-B-Si-Mo-based corrosion-resistant and wear-resistant alloy is formed on the inner peripheral surface of the lateral hole.
-The composition of the Mo-based corrosion-resistant wear-resistant alloy is B: 0.6 in% by weight.
~ 3.2%, Si: 0.5-8%, Mo: 5-37%,
C: A barrel having a lateral hole containing 0.01 to 1%, the balance being Ni and unavoidable impurities.