JP2912473B2 - Manufacturing method of long preform by spray deposit method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a long preform by spray deposition.

[0002]

2. Description of the Related Art In general, the spray deposit method involves atomizing molten metal with an inert gas,
A method in which finely pulverized droplets are rapidly cooled and solidified during scattering and deposited on a collector to obtain a preform (formed material) having a desired shape (for example, JP-B-54-29985 and JP-B-56-12220). And JP-A-64-152
No. 64, etc.) and has features such as the ability to form a uniform microstructure by rapid solidification, no macro segregation, and good workability / forgeability as compared with the ordinary casting method. I have.

[0003] Further, the spray deposit method,
Compared to the thermal spraying method in which a group of molten metal particles are sprayed onto the surface of a coating material to form a laminated coating, the porosity is reduced, a high-density preform is obtained, and the productivity is high.

However, when such rapid solidification is performed extremely, porosity occurs, and a high-density preform cannot be obtained. In other words, the cause of this porosity is that if the cooling by gas becomes too extreme, the ratio of solid phase particles in the particles deposited on the preform will increase, and the liquid phase and semi-molten It is considered that the gap between solid phase particles becomes porosity as it is because the number of particles decreases, and when the particle temperature becomes relatively low, the particles are less likely to flatten at the time of collision, and shadow Is formed.

[0005] However, if the temperature of the subsequent particles is sufficiently high in a molten state, the shadow portion can be filled, but if the temperature is low, it is considered that the shadow cannot be filled and porosity occurs.

As described above, the cause of the porosity in the preform is considered to be related to the temperature, but is still unclear. For example, when manufacturing a tubular preform, a porosity layer may be generated in the vicinity of the tube collector. When this is analyzed, it is considered that the temperature of the particles in contact with the collector becomes low, and porosity is generated for the above-described reason.

Therefore, it is conceivable to preheat the tube collector. When applying high-frequency preheating, plasma preheating, etc. as this preheating method, discontinuity of preheating or a temperature difference in the longitudinal direction occurs in the case of a tubular long object, there is still partial porosity generation, and When a clad layer is bonded to a solid billet, there is a problem that a porosity layer is generated between the collector side and the deposited layer.

On the other hand, the above-mentioned Japanese Patent Application Laid-Open No. Sho 64-15264 discloses a method of manufacturing a composite metal material using a spray deposit method, in which a separate preheating molten metal is used before spray depositing for a dissimilar metal. A method of manufacturing a composite metal material in which a metal is allowed to flow down onto a plate-like base material to form a coating layer on the base material, and a spray flow is deposited on the coating layer for use with a different kind of metal is disclosed. The method, like the general method of manufacturing rolled clad steel, to increase the bonding strength between the dissimilar metal and the base material, between the base material and the dissimilar metal,
For example, preheating molten metal to prevent carbon diffusion (for example,
Nickel) with a coating layer (so-called foil) interposed, and the boundary between the sprayed particles remains, so that porosity cannot be completely prevented, and
There is a problem that this cannot be applied as it is to a long hollow or solid preform.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems at once, and its gist is to provide an atomizer for ejecting an inert gas to a ceiling side of a chamber. A first container containing a molten metal for performing a spray deposit, receiving a spray flow from the atomizer, and rotating and moving in the longitudinal direction, a collector for a columnar long preform. Is laid laterally through the chamber,
On the upstream side in the moving direction of the collector, a second container is provided which is supported in the chamber and contains a preheating molten metal of the same quality as the molten metal of the first container. A molten metal stream for preheating is thinly poured from a spout that is wide and close to the axial direction of the collector to form a metal layer on the outer periphery of the collector that dissolves a porosity layer due to the spray flow. After that, there is provided a method for producing a long preform by a spray deposit method, wherein the porosity of the preform on the collector side is suppressed by depositing the spray flow.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings. FIG. 1 is a schematic view of an apparatus according to an embodiment of the present invention, and FIG. 2 is a side view as viewed from an arrow A in FIG.
It is suitable for producing a hollow or solid long tubular preform made of a ferrous or non-ferrous metal.

In FIG. 1, reference numeral 1 denotes a long tube collector (made of S25C) or a base material, which is supported by collector supports 3 and 3 which penetrate the chamber 2 in the lateral direction and are provided outside the chamber 2. 5 to 500
While rotating at rpm, the vehicle slowly moves from right to left in the figure.

Incidentally, this collector or base material 1
When producing a hollow preform, it becomes a collector, and when producing a solid preform, it becomes a base material. Hereinafter, both are collectively referred to as a collector.

Inside the chamber 2, a preheating tundish 4 is provided on the upstream side in the direction of movement of the collector 1 so as to be tiltable. On the ceiling side of the chamber 2, a spray deposit for spray deposit is formed in a downward flow. A container 5 such as a tundish or a crucible is provided. An atomizer 6 is mounted below the container 5.

The tundish 4 and the container 5 contain homogeneous molten metal (for example, SUS304) 7, but the molten metal 7 contained in the tundish 4 is maintained at a slightly high temperature. The pouring opening of the tundish 4 is wide so that a thin metal layer 8 can be formed around the collector 1 to form a metal layer 8 having a uniform thickness. The temperature of the metal layer 8 is measured by a thermometer such as a pyrometer (not shown), and the tilt of the tundish 4 is adjusted to control the amount of molten metal.

Below the position where the tundish 4 is arranged, an auxiliary straightening roll 9 is provided adjacent to the collector 1 so as to further smooth the metal layer 8 and to drop the metal flow. Prevention. Further, on the upstream side of the tundish 4 (with respect to the moving direction of the collector 1),
A preheater 14 may be provided as needed.

Immediately below the tundish 4, a saucer 12 lined with a refractory is provided to receive the pouring metal that could not be captured by the collector 1. Further, the spray stream 10 that cannot be captured by the collector 1 is collected by a dust collector (not shown) via an exhaust gas ventilator 13, similarly to a normal spray deposit apparatus.

Next, the operation of the present embodiment will be described. First, a thin molten metal stream for preheating is poured from the wide pouring port of the tundish 4 onto the outer periphery of the rotating collector 1, and the entire circumference thereof is Then, a smooth metal layer 8 is formed. At this time, the unevenness of the layer surface is eliminated by the auxiliary straightening roll 9 if necessary, thereby preventing a porosity layer due to the unevenness.

As a result, the collector 1 is evenly preheated in the axial direction. The preheated collector 1 is moved to a position immediately below the spray deposit container 5 to deposit the spray stream 10.

The spray flow 10 is applied to the chamber 2
Although it is scattered inside and mixed into the tundish 4, there is no problem because it is a molten metal of the same quality. As a result, the collector 1 is preheated by the previously coated metal layer 8 to prevent the occurrence of porosity, and even if a porosity layer is formed by spray deposition, the collector 1 can be dissolved and removed by the metal layer 8. .

[0020]

According to the present invention, since a collector or a base material for forming a hollow or solid preform is laid laterally through the chamber, a long preform can be formed. Since the metal layer poured from the wide spout of the tundish is preliminarily formed on the outer periphery of the collector or the base material and the collector or the base material is preheated, there is no irregularity on the surface of the metal layer, and the length is long. Even though the length is long, uniform heating is performed to prevent generation of porosity, and a long preform of good quality can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

[Explanation of symbols]

1 collector, 2 chamber, 4 tundish,
5 containers, 6 atomizers, 8 metal layers, 10 spray flows, 11 preforms

Claims (1)

(57) [Claims] 1. A first container containing a molten metal for performing spray deposition is provided on an upper side of a chamber via an atomizer that ejects an inert gas, and receives a spray flow from the atomizer, And it turns,
First , a column-shaped elongate preform collector that moves in the longitudinal direction is laid laterally through the chamber, and is supported in the chamber on the upstream side in the moving direction of the collector, and is provided in the first container. A second container containing a preheated molten metal of the same quality as the molten metal is provided, and the second container is wide and close to the axial direction of the collector.
A thin stream of molten metal for preheating is poured from the spout along the porosity, and a porosity by the spray flow is spread around the collector.
A method for producing a long preform by a spray deposit method , wherein a porosity of the preform on the collector side is suppressed by forming a spray layer after forming a metal layer for dissolving a metal layer.