JPH02213455A - Wear resistant member - Google Patents

Abstract

PURPOSE:To produce a wear resistant member excellent in mechanical strength by diffusion-joining a coating layer consisting of wear resistant hard grains and matrix metal to a base material composed of a martensitic stainless steel containing specific amounts of C. CONSTITUTION:For example, plural screw elements 14a, 14b fitted and fixed on the outside periphery of a screw shaft 11 of an extruding screw 10 for plastic working are constituted by diffusion-joining a coating layer 14B consisting of hard grains of wear resistant material and matrix metal to the surface of at least a part of a base material 14A formed of a martensitic stainless steel containing <=0.5wt.% C. Further, the above hard grains are composed of either of carbide grains and boride grains or of a mixture of plural kinds (e.g. WC), and the above matrix metal is composed of any of Ni-base, Co-base, and Fe-base self-fluxing alloys. By this method, the screw elements 14a, 14b free from the occurrence of the peeling and cracking of the coating layer 14B can be produced relatively easily.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention is intended for use in applications where abrasion resistance is required for screws and the like used in processing plastics filled with optical fibers such as glass fibers. It is related to members.

(Prior Art) In recent years, plastics containing fillers such as glass fiber and silica have been used. Cylinders, screws, etc. for processing such plastics are subject to wear due to the above-mentioned filling, and therefore are strongly required to have wear resistance. In particular, screws and components such as non-return valves used in combination with screws have complicated shapes.
Screws for extruders are hollow split screws that need to be fitted into the screw shaft to form a single screw, and require both abrasion resistance and mechanical strength. . Therefore, it has been slower to impart wear resistance to screws and check valves than to cylinders, and conventionally, they have been treated with nitriding or carburizing, or have been made with wear-resistant materials such as Ni-based self-fusing alloys. A thermally sprayed coating was used.

(Problem to be solved by the invention) Since the nitrided screw has a thin nitrided layer of 0.2+- or less, and the carburized process has a low treatment hardness of about Hv800, 30% by weight of the nitrided screw is mixed into the glass fiber. In the case of plastic, the flight part of the screw wore out so thickly that it became unusable after about one to two months. In addition, when coating a gold film by thermally spraying a Ni-based self-fluxing alloy, etc., there is a large difference between the thermal expansion coefficient of the coating layer and that of the screw base material, so annealing treatment cannot be applied after coating. is essential;
As a result, the hardness of the screw base material was very low, and there was a drawback that the full mechanical strength required for the screw could not be obtained.

Furthermore, in hollow segmented screws, the entire screw is made of a composite of TiC particles and Fe-based self-fluxing alloy, but this is a hard and extremely brittle compound, and the flight part and hollow There is a drawback that the key groove provided in the hole is destroyed.

The object of the present invention is to provide a wear-resistant member that has excellent wear resistance, sufficient mechanical strength, almost no peeling or breakage, and a long service life.

[Structure of the invention]

(Elaborate means to solve the problem) A base material made of atomic stainless steel, hard particles of wear-resistant material, and a matrix metal that are diffusion bonded to at least a part of the surface of the base material. It consists of a covering layer.

The above-mentioned hard particles are preferably a mixture of one or more types of carbide and boride particles, and the matrix metal is preferably a mixture of Nl group, LL group, etc.
It is preferable that the alloy is a self-fluxing alloy containing either three groups or one Fe group.

(Function) The coating layer made of hard particles of wear-resistant material and matrix metal provided on the surface of the base material is formed by so-called sintering, and has excellent wear resistance due to the presence of hard particles. It has the following. On the other hand, if the base material is formed of martensitic stainless steel with a carbon content of 0.5 weight coefficient or less, the temperature of the AI transformation point of the base material is temporarily maintained during cooling after the completion of sintering of the coating layer. By this simple heat treatment operation, the hardness of the base material 'fr:HRC20
~30, and does not cause cracking or peeling of the coating layer.In addition, the base material and the coating layer are diffusion bonded, so they have a very high bonding strength, and the coating layer does not peel off during use. Not at all.

That is, in the wear-resistant member of the present invention, the base material has HRC20~
It has a sufficient mechanical strength of 30% and has a highly abrasion-resistant coating layer firmly bonded to its surface. It also satisfies mechanical strength and can be applied to various wear-resistant members.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 to 3. 1 and 2 show the next side of a screw 10 for extrusion in the entire plastic processing of the present invention, and this screw 10 has a screw shaft 11 extending over the entire length of the screw=+0, Threaded portion 12a at its tip
It consists of a screw head 12 which is fixed at the edge of - and a plurality of screw elements +43, +4b, etc. which are fitted and fixed to the outer periphery of the screw shaft 11 through the entire key 13.

The screw elements +4a, 14b... have lead dimensions, capacitance, shape, etc. that change depending on their position on the screw shaft 11, and are divided according to these changes, with some parts being divided as screws. Although there are parts that have multiple simple protrusions and grooves rather than shapes, all of these will be described as the entire screw element.

FIG. 2 is a view of one screw element viewed from the +4ati surface side, and 15 is a hole, 16 is a keyway, 17 is a valley bottom, and 18 is a top.

In this embodiment, the screw shaft 11, screw head I2, and key 13 are made of metal materials commonly used for these, and the screw element +48. +
The present invention is applied to 4b... That is, to explain using an example of the screw element 14ai, the screw element 14a has a base material +4A and a coating layer 14 provided on a screw-shaped portion (hereinafter referred to as a flight portion) on the outer periphery.
It consists of B. The base material 14A is 5U according to the JIS standard.
8420J2 (component weight%, C: 0.26~
0.40, 8 i: 1.00 or less, formed by Mn.

The coating layer 14B is made of a Ni-based self-fusing alloy (component weight %, B: 2.40. Si: 4.70. Fe: 1.
5 or less = C"0.5, Bal: Ni, others 0.9 or less) Sintered.

In addition, the covering layer 14B was manufactured as follows. A slurry was prepared by mixing an average of 14 parts by weight, and the slurry was coated on the flight portion of the base material 14A using a spray device. After drying, the coated part is machined on a lathe so that the thickness of the coated part becomes 1 m, and then the powder of the Ni-based self-fusing alloy is formed on the flight part together with the base material 14A. The sample was placed in a sintering crucible in contact with the coated portion and sintered.

The sintering conditions were: degree of vacuum: 1 x IQ-'torr, sintering temperature: 20-400°C (30°C/H, 400-11
00℃ (5℃/-).

1100℃ (held for 30 minutes), 1100-650℃ (10
℃/-).

650℃ (At transformation point, held for 60 minutes) → Furnace cooling.

The hardness of the coating layer 14B of the screw element +43 manufactured as described above is distributed in the range of uvgoo to 1100, and the hardness of the base material 14A is HRC 20 to 30, which has sufficient mechanical strength. The base material 14A and the coating layer 14B were tightly adhered to each other by diffusion bonding, and no peeling or cracking occurred during the manufacturing process.

Furthermore, I, a friend, produced the screw element in this way + 4 al 14 b...Using sound, I made the screw 10 for extrusion using the method shown in Figure 1, mixed in 30% by weight of glass fiber, and used it for extrusion molding of plastic. Used results,
Wear on the flight part has decreased significantly, and it has been confirmed that there is almost no wear even after two months of testing.Furthermore, the keyway 16 of the base material 14A has not been deformed at all, and the screw shaft 11 and the key 13 There was no looseness in the engagement relationship.

FIG. 3 shows an example in which the present invention is applied to an injection molding apparatus for plastic processing, where 20 is an injection cylinder;
21 is a screw, 22 is a screw head, 23 is a front spacer for a check valve, 24 is a rear spacer for a check valve,
25 is a check valve. Among the various parts of the core, the parts that come into strong contact with plastics and metals and produce abrasion noise are the inner surface of the injection cylinder 20, the surface of the flight part of the screw 21, and the front and rear spacers 23 and 24 for the check valve.
and the contact surfaces of the check valve 25 and the outer surface of the check valve 25, and the parts where such wear is mainly caused are marked with symbols 20B, 21B, 23B, and 24B.
And as shown by 25B, a covering layer similar to the above-mentioned covering layer 14B is provided, and these base materials 2OA.

21A, 23A, 24A, and 25A are made of the same material as the screw base material 14A described above.

In this embodiment, the same effects as in the above-mentioned embodiment can be obtained, and in particular, the life of the front and rear spacers 23 and 24 for the check valve and the check valve 25, which conventionally suffer from severe wear and short life, can be significantly extended. I can do it.

The above-mentioned example shows an example in which WC is used as the hard particles forming the coating layer 14B, etc.
* may be a boride, or a mixture of all of these may be used. Next, in the above example, a Ni-based self-fusing alloy was used as the matrix metal for the hard particles, but the following examples are not limited to this, and in particular, a Co-based self-fusing alloy or a Fe-based self-fusing alloy 1- Almost the same characteristics and characteristics as the CN single-base self-fusing alloy can be obtained.

Furthermore, in the above embodiment, the base material such as the base material 14A is 5U8A20J2' according to the JIS standard! : Although the example is shown, the example is not limited to this, and SUS 403.
410,410J+, 416,420JI and 42
If the martensitic stainless steel has a carbon content of 0.5% by weight or less, such as 0F, the same effect as 11 can be obtained, although the mechanical strength will vary slightly.

Furthermore, it goes without saying that the present invention is applicable not only to the above-mentioned members for the glass chip processing apparatus, but also to various other members.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a wear-resistant member consisting of a coating layer having extremely high wear resistance and a base material having sufficient mechanical strength, and the peeling and cracking of the coating layer can be prevented. There are advantages such as relatively simple manufacturing.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway view showing an example of a plastic extrusion screw according to the present invention, FIG. 2 is a front view of the screw element shown in FIG. It is a sectional view showing a part of. 10...Screw, 11...Screw shaft, 2.
・・Screwhep) e, +3 ・・Key 4a, +4b・
...Screw element, 4A, 20A, 21A, 23
A, 24A, 25A...Base material, 4B, 20B, 21B
, 23B, 24B, 25B...covering layer, 5...hole,
16...key groove, 17...bottom,...top,
20...Injection cylinder,...Screw, 22.
・Screwheb・・・Front spacer for non-return valve, ・・・Rear spacer for non-return valve, ・・・Pre-return valve 0

Claims (1)

[Scope of Claims] 1. A base material made of martensitic stainless steel with a carbon content of 0.5% by weight or less, and at least one of the base material made of hard particles of a wear-resistant material and a matrix metal. A wear-resistant member consisting of a coating layer that is diffusion bonded to a portion of the surface. 2. The hard particles are either carbide or boride particles
Claim 1 characterized in that it is a mixture of two or more types.
Wear-resistant member as described. 3. The wear-resistant member according to claim 1 or 2, wherein the matrix metal is a self-fusing alloy of any one of Ni-based, Co-based, and Fe-based.