JPS61262420A - Inner liner for hot extruder - Google Patents

Abstract

PURPOSE:To increase the strength at high temp. and wear resistance and to reduce the cost by performing a powder body build up welding on the using face of an inner liner and by forming the build up layer which holds a hard particle with dispersion on the base consisting of Fe base, Ni base or Co base alloy or these alloys. CONSTITUTION:An inner liner 3 is fitted into the outer liner 2 which is fitted into the inner diameter of the container tyre 1 of the container for hot extruder and a powder body build up welding zone 4 is formed on the inner peripheral part of the inner liner 3. The inner liner 3 is to form a build up layer 4 by powder body build up welding on the inner peripheral face after subjecting to solution heat treatment and aging treatment in advance with hot tool steel, super heat resistant alloy, etc. as the base metal and this build up layer is made by the melt melting the powder which can optionally select each component and its compounding ratio, so the high temp. strength and wear resistance can be increased sufficiently.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides powder meat with excellent high-temperature wear resistance, etc., which fits into the inner diameter of a container for a hot extruder such as Kiepro NL Cw Cu alloy, FC, etc. This relates to a full inner liner.

[Conventional technology]

Conventionally, martensitic die steel has been used for inner liners for hot extruders. However, when extruding steel alloys, etc., where the temperature of the extruded material exceeds 600°C, the inner surface of the inner liner comes into contact with the high-temperature extruded material during use and is subjected to high extrusion pressure. In this case, the inner surface is severely worn out and worn out.
In addition, high-temperature tempering causes a decrease in strength, and in some cases, cracks occur in the extrusion direction of the inner liner, resulting in the end of its life in a short period of time. For this reason, so-called super heat-resistant alloys have recently been used, and Cupron N
When the temperature of the extruded material exceeds 1000°C, as in extrusion i, or when the temperature of the material to be formed exceeds 750°C, such as copper alloy.
When extruding tubes at 50℃ and with a relatively short extrusion time, it is possible to improve the life by about 15-5 times compared to inner liners made of martensitic die steel, but due to the high cost, it is not necessary to use tools. Cost savings have not been achieved. Also, like pure copper, the temperature of the extruded material is 800-900
℃, but in extruded materials with high thermal conductivity, the temperature of the inner liner increases rapidly and the temperature difference in the radial direction of the inner liner increases, resulting in large thermal stress and shortening the service life of even super heat-resistant alloys. is short. Particularly in the case of extrusion of pure copper bars, which requires a long extrusion time, the life expectancy is significantly reduced, and the extrusion does not contribute to any reduction in tool costs.

On the other hand, it has been proposed to apply weld build-up to the inner peripheral portion of the inner liner using a welding rod.

The present inventors have developed an inner liner in which the austenitic hot work tool steel disclosed in JP-A No. 59-104214 is used as a base material, and a super heat-resistant alloy or the like is sensually welded to the working surface of the tool steel, and the effect has been achieved. In this method, the inner circumferential surface of the inner liner is overlaid with Ni-based super heat-resistant alloy or the like by MIG welding. However, (1) In the case of MIG welding, the amount of penetration is large and it is difficult to adjust the build-up thickness, so after applying 2-3 layers of build-up, the inner peripheral surface is processed to the specified dimensions. This causes variations in the thickness of the built-up layer. In addition, (2) it is difficult to adjust the overlay specifications, etc., so hot cracking and cooling cracking are likely to occur (TI
It is necessary to repair using the G welding method. Therefore, due to the above two reasons, wear and deformation occur locally, which is still insufficient in that the lifespan of the inner liner varies widely. Sara K.

In the case of the MIG welding method, there is a limitation in that it can only use sensuous materials within the range that can be manufactured into wire rods.

[Problem that the invention seeks to solve]

As explained above, conventional inner liners lack high-temperature strength and abrasion resistance when extruding Cu, Cu alloys, and KiepaNi, where the temperature of the extruded material exceeds 600°C. However, even though they are expensive, I have not been able to save money on tools.

An object of the present invention is to provide an inexpensive inner liner that has excellent high-temperature strength and abrasion resistance.

[Means for solving problems]

The present invention uses hot work tool steel, super heat-resistant alloy, etc. as a base material, and uses powder overlay welding on the surface of the base material to form a base material VcWc' made of Fe-based, Ni-based, or CO-based alloy, or an alloy thereof. * Tsc + TtN * TiB15
The above object is achieved by providing a built-up layer in which hard material particles such as We #5iO1 are dispersed and held. Note that when an austenitic alloy is selected as the base material, it is also useful to perform appropriate heat treatment such as aging treatment after powder build-up welding to improve the strength of the build-up layer.

[Effect]

The inner liner of the present invention has a powder build-up layer on its use surface. This build-up layer is made of a molten material made by melting each component and powder whose blending ratio can be selected arbitrarily.
High temperature strength and wear resistance can be made sufficiently high. In addition, in powder build-up/welding, the penetration rate is extremely small at 54 or less, allowing for subtle adjustments to the build-up layer thickness, and there is almost no risk of hot cracking that occurs with MIG welding. This was revealed as a result of the experiment.

In addition, if an austenitic alloy is used as a base material, the base material has a large thermal expansion coefficient, so the contraction during cooling after build-up is large (this is due to the tensile stress caused by the cooling shrinkage pressure of the build-up layer). It was found that the occurrence was low.

This shows that the overlay material can be made into a material with higher strength, and on the other hand, it is possible to make the overlay material higher in strength than when combined with the powder overlay method, which allows the material to be selected regardless of the manufacturability of the welding rod. This makes it possible to manufacture high-performance inner liners. Further, since the austenitic alloy has high high temperature strength, the retention strength of the built-up layer is high.

In addition, the plasma powder build-up welding method allows easy control of heat input, and enables finer control of penetration amount, build-up thickness, etc.

〔Example〕

Table 1 shows examples of combinations of inner liner base material and build-up material in examples of implementing the present invention, as well as practical results, using index values when the number of pieces extruded under the same extrusion conditions as the conventional A286 inner liner is 100. show.

Also table 2Kr! I! The composition of each alloy used is shown below.

Margin Table 1 Below: Figure 1 is a sectional view of a container showing one embodiment of the present invention. 3 is an inner liner base material, and 4 is a powder build-up layer, which is press-fitted into the outer liner fitted into the inner diameter of the container tire 1.

The inner liner base material was previously subjected to solution treatment and aging treatment, and then a fleshy layer was formed on the inner peripheral surface. In all cases, there were no cracks in the build-up layer, no significant deformation, etc., and it was possible to grind and finish as is.

In Table 1, the usage results are blank after the liner has been completed, but before or during actual machine testing. From the surface of the wood, it can be seen that all of the products for which the test results were found have a longer lifespan than the comparative materials.

The same type of life extension is also expected for products before or during use.

〔Effect of the invention〕

As stated above, the inner layer for a hot extruder of the present invention is welded on its use surface by powder build-up welding, and has particularly high temperature strength, high temperature wear resistance, and high temperature softening properties. It has significantly increased resistance. In addition, because of its composite structure, it can be supplied at a relatively low cost, and in addition to improving tool life, its industrial value is extremely large.

In addition, in the case of an inner liner for hot extrusion, what is required is high deformation resistance during hot heating, and as a build-up material, Fe-based, Ni-based, Co
Among the basic super heat-resistant alloy steels, materials with strong high-temperature strength are desirable. The present invention is not limited to the composition of these super heat resistant alloys (any conventional super heat resistant alloys may be used.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a container having a container with a powder overlay liner. 1... Tire (outer cylinder), 2... Outer liner (
intermediate cylinder), 5...inner liner (inner cylinder), 4...
・Powder overlay welding part. Procedural amendment (voluntary) 1. Indication of the case 1985 Patent Application No. 105232 2, Name of the invention Inner liner for hot extruder 3, Person making the amendment Relationship to the case Patent applicant address 1-2 Marunouchi 2-chome, Chiyoda-ku, Tokyo Name (50g) Hitachi Metals Co., Ltd. 4
, Detailed description of the invention in the specification to be amended. 5. Amendment contents table 1

Claims (1)

[Claims] 1. In an inner liner for a hot extruder, the surface to be used is powder welded to form Fe-based alloy, Ni-based alloy,
An inner liner for hot extrusion, characterized in that it has a base made of a Co-based alloy, or a base made of these alloys, and a built-up layer that disperses and holds hard particles. 2. A hot extruder according to claim 1, characterized in that the base material is austenitic die steel, Fe-based, Ni-based super heat-resistant alloy, and powder build-up welding is performed by a plasma method. inner liner.