JPS6114065A - Manufacture of metallic block, casting or section into whichhard metallic particle is buried and device thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing metal blocks, castings or profiles by transferring molten metal so rapidly that solidification continues from an upper heating zone to a lower cooling zone during chilling. .

Methods are already known for producing metal blocks by cooling molten metal in a controlled manner so that segregation does not occur. Various alloy mixtures are added to the molten metal so that the metal has several properties, such as hardness, toughness, weldability, wear resistance, and processing properties, by adding different alloy mixtures to the molten metal and crystallizing them in different ways depending on the concentration of the mixture and the cooling method. Gives characteristics such as gender. In this way, it is customary to consider the balance between characteristics depending on the intended use.

That is, as far as steel is concerned, high toughness cannot be obtained without sacrificing wear resistance, as in the case of manganese steel, and high wear resistance cannot be obtained without sacrificing toughness, as in the case of carbide-containing special metal molds. It is known that steel alloy molds provide only average hardness and average wear resistance.

To overcome this dilemma, it is known to use high-toughness materials, which are hard materials with protective layers welded to them, for objects exposed to severe abrasive conditions. This material increases its carbide content by dispersing metal carbides into the weld pool under certain conditions. This method has a limited thickness of the protective layer and is prone to tearing, so the probability of success is low and the cost is extremely high. Attempts to stack multiple layers tend to produce grating cracks, which further promotes layer fracture.

Comparison of hard materials, such as tungsten carbide, titanium carbide or hard metal scrap, which do not melt at the surface but are only kept solid by the compression of the steel matrix during solidification due to the large coefficient of thermal expansion. It is also known to produce castings by pouring particles of hard material into molten steel at a relatively low temperature. In this state, the hard material particles present on the surface of the workpiece are relatively easily separated under strong stress.

Since the hard metal particles are poured into the molten matrix material and the cooling temperature is connected for several minutes, it is also possible to set the temperature of the matrix material much higher than the melting point of the hard material particles so that the hard material particles are sufficiently melted. It is publicly known. There are two implementations of this known method. One involves alloying the hard material with cobalt and other mixtures that lower its melting point, the other is characterized by the application of extremely high temperatures at which the carbides decompose and carbonize the steel matrix. .

In the first aspect, the hardness of the hard material is relatively low, and in the second aspect, the hardness of the hard material is relatively low.
In this embodiment, the hardness of the matrix is significantly reduced. In addition, most of the hard material melts and recrystallizes in the easily soluble material,
Particularly weak carbon decomposes from the melt. This results in the formation of shrinkage cavities and cracks, and thus the hard material particles easily separate when stress is applied.

The object of the present invention is to enable mass production of metal blocks, metal castings or metal shapes with relative ease, to have both high toughness and high wear resistance, and to have uniform and strong hard material particles in a metal matrix, especially a steel matrix. A product that enables a product in which a relatively small amount of hard material remains in the form of particles in the matrix and crystallizes to avoid weakening of the matrix by shrinkage nests and hard material decomposition products, especially carbon particles. The goal is to propose the following.

In order to achieve this purpose, in the present invention, a hard material in the form of powder, particles or crystal grains is fed from an upper heating zone into the melt at a temperature below the melting point of the hard material during cooling of the molten metal, and is placed on the surface of the melt. This is achieved by distributing it.

In order to bond the hard material particles very strongly into the metal matrix, the surface of the particles is heated in a heating zone for a short period of time to a temperature above their melting point.

For example, if the height of the molten metal flowing into the chill casting formwork is relatively large, reaching 1 m7, the height of the hard material particles from the surface of the molten metal to the bottom of the molding formwork is relatively large. The transition time, for example, 30 seconds, is such that the hard material particles start dispersing approximately the transition time earlier than the start of cooling of the chill form, and the dispersion progresses during the cooling time including the transition time, and the hard material particles are dispersed. The cooling block is set to be distributed over the height of the cooling block according to the progress time of the cooling block.

Another preferred solution for achieving the objects of the invention is to constitute a heating zone with a layer of molten slag heated by electrical resistance heating to a temperature above the melting point of the hard material particles, and to increase the height of this heating zone by increasing the height of the hard material particles. It is provided by a method in which only the surface of the particles melts and the molten metal is continuously added to the cooled molten metal in a stream at a temperature below the melting point of the hard material particles.

The hard material particles remain in the hot molten slag for only about one second before settling into the molten metal. Hard material −
Measurements carried out on a metal block during the solidification of the metal surrounding the 15 material particles show that a zone several micrometers deep remains where the steel components penetrate into the hard material surface and eventually solidify in a eutectic state. . Hard materials with insufficient liquefaction have a depth of 100
A dendritic zone of ~300 micrometers is generated, and the crystal structure becomes poorly eutectic due to the quenching process.

In addition, a slight diffusion of hard material occurs in the dendritic zone and also in the steel matrix.

Therefore, the height of the molten metal is kept reasonably low so that the settling time of the hard material particles is relatively short.

Since the injection of molten metal into the chill is continuous, the concentration of the alloying material and the diffusing hard material particles are always in equilibrium, thus avoiding continuous concentration and consequent decomposition in the crystals. A homogeneous final product is obtained.

Therefore, various steel materials can be used depending on the application, and steel materials with hard materials added have better toughness, weldability, and castability than steel without additives, and the hardness and resistance change depending on the addition period. Since abrasiveness becomes extremely high, workability decreases.

For example, it consists of a matrix of high chromium alloy steel,
Monometal added with tungsten carbide exhibits higher wear resistance than 82 type sintered metal or H8S welded steel. This material may crack or crack when used under protective gas or when electrically butt welded.

Can be welded without any problems.

Therefore, for example, parts such as chisels, scrapers, scrapers, etc. can be made from a metal with added hard materials and holders, blades, shafts, etc. can be welded to them, and the latter can be processed as necessary. good.

Since the method of continuously supplying new molten metal toward the mold according to the solidification rate can be carried out with a continuous casting mold, it is possible to produce not only blocks and castings but also shapes of arbitrary length. In particular, by using this continuous casting method, the required additive zone is distributed in the cross section, for example, hard material particles are dispersed in the outer zone, and since the height of the melt is low, abrasion stress will later act on this outer zone. This can result in a relatively accurate hard material particle distribution in the final product. Thus, the additive-free zone, for example the inner part, can be machined (bored) and the matrix of the inner zone is not disturbed, thereby increasing the tensile strength.

It is also an advantage of the method of the invention that it can be applied to non-ferrous metals, such as light alloys. New possibilities are thus obtained for constructing wear-resistant armor plates, aircraft or rocket parts.

This completely new type of material is not only used to extend the service life and reduce the production costs of machine parts and tools that are subject to wear, but also to improve It can also be applied to give completely new possibilities to the composition of aggregates that have obtained the necessary properties.

The application of this new material to wear-prone and friction-prone products, such as in the case of rail car rims, where hard material particles hold up poorly on the surface, increasing roughness and therefore friction, can be avoided. Particularly advantageous. By using particles of appropriate size and shape and of appropriate hard material, effects depending on the application can be obtained.

The advantageous combination of properties of tungsten carbide added steels are listed below: high wear and abrasion resistance, - bending, rolling, - casting processable, resistance to decomposition or fracture, resistance to child heat. , and can be electrically welded without fear of cracking, can be cured, and can be heat treated.

When applying the method of the invention, hard materials must be used that do not melt at the temperature of the molten metal. Also, the specific gravity must be greater than that of the molten metal so that it sinks into the molten metal.

Hard material particles can be obtained from natural products or by sintering or melting and optionally grinding.

In order to properly distribute the hard material and achieve material homogeneity in the final product, the particles must be sorted according to size. This can be achieved by sieving or air or water separation. By homogenizing the hard material particle distribution from zone to zone in the final product by means of a variable addition method, it is possible to achieve a pattern of attachment, for example, a continuous transition valve from zone to zone.

The method of dispersing particles, powders or crystals into the cooling molten metal can be the same but impart other properties to the material. For example, armor plates can be made less weldable and less machinable.

An example of this is the method of adding carborundum or corundum to a light alloy.

Using multiple additive materials to provide different properties, such as tungsten carbide for wear resistance and carborundum for fire resistance, in the same molding process while correctly controlling the timing and amount of addition. be able to. In this way, other new types of materials with composite properties can be obtained. Selection of alloys and their respective addition concentrations can be readily determined by those skilled in the art through experimentation.

The cross-sectional shape of the mold may be set so that it can be applied to the production of shaped materials. A hollow profile is produced by introducing the core, and cooling water is passed through this hollow profile as well as the outer frame.

Type of alloy and mixing ratio with hard material: Preferred selections are illustrated below. Suitable application areas will be discussed while taking into account the mode of wear. Wear can be broadly classified into four types: a) Non-alloyed or low-alloy steel with addition of hard materials: this alloy is characterized by containing 0.8-1.8% manganese and about 1% silicon; . In addition to the mechanical quality values provided by silicon, the high silicon content also influences the melting in the mold.

If the silicon content is insufficient, the melt will not be stable enough if the molten material is supplied by melting the electrodes.

The silicon may be dispersed in the hot molten slag or incorporated as part of the electrode material. 80 to 250 g of hard material per ko of steel alloy must be added to this matrix material. If less than 80g is added, wear resistance will be insufficient. Addition of hard materials of 2509 or higher will cause cracks under bending stress. The particle size of the hard material also plays a role here. Particle size is determined by the given wear conditions. The basic rule is as follows: Particle diameters of up to 0.8 mm are preferred when subjected to rolling, impact or frictional stresses. For example, when strong grinding or cutting stress is applied as in the case of a boring head, a size of 3 to 5 mm is preferable.

b) Martensitic Steels: Steels that withstand severe wear due to mineral grinding primarily belong to this category. Wear resistance is significantly increased by adding hard materials. Preferred martensitic alloys are shown in FIG. 8 in order of hardness RC (Rockwell).

C) Austenitic Steels: This category includes rust-free and acid-resistant stainless-chromium-nickel steel alloys. For example, Cr18%, Ni8%
A welding material (Material No. 1.4370) containing 19% of Cr, 9% of Ni and Mo, or 18% of Cr, 8% of Ni, and 6% of Mn is known. These alloys are used when corrosive environments are expected.

It has no protective effect against mechanical wear, especially from mineral grinding.

By adding the hard particles of the present invention, completely new uses that were previously unimaginable become possible.

Other manganese-based hard steels are described below. They are particularly shock- and pressure-resistant, characterized by containing 1.2% carbon and 12-17% manganese.

There are limits to wear resistance. By adding the material of the present invention, wear resistance is increased and new applications become possible. A new special alloy with extremely high impact and wear resistance is obtained with the following additions: C=1.0%, 3i=1
．． '8%, Mn=17%, Cr-17%, W=3.5
% (average amount). By adding the hard materials of the invention, the wear resistance is significantly increased and a completely new material is obtained which can be used in a variety of applications with historical demand.

d) Nickel Based Alloys Materials containing high levels of nickel are unsuitable for use under impact and abrasion conditions. If the hard metal particles of the present invention are added, nickel, parrot leather, tuxteroy B
, Hastelloy C is also under high wear conditions.

Can be used under the handle. Extremely good corrosion resistance is obtained even at high temperatures, and hard material bonding offers completely new applications. This is because corrosion decomposition particles from molten metal are not mixed into the matrix during bonding.

The continuous operation of the forming apparatus has the advantage of vertical solidification of the matrix material, resulting in a compact material with excellent processability. The use of heating zones containing electrically heated slags can also benefit alloys with high Kumuro content.

Electrically heating the slag causes strong rotational motion in the slag and molten metal. The negative resistance properties of the slag material and the magnetic field of the flow cause it to constantly move out of the flow path and the hottest area in the slag. This phenomenon is increased by continuous rocking and rotation of the electrode. Fine crystals are created by the continuous rotation of molten metal. Because the molten slag is hotter than the molten metal, the molten metal material is always sandwiched between the hotter slag boundary zone and the cooler crystalline zone, and even if some crystals decompose, they will not return to the hot zone again. Since it is dissolved, the above effect is further increased. In addition, degassing becomes easier in the high temperature range.

A thin layer of slag covers the mold walls and acts as an excellent means of lubrication during demolding of the solidified material, eliminating the need for injection of other lubricating greases or oils containing carbon.
This is advantageous because no carbonization of the metal occurs and there is no need to add gaseous components or provide injection equipment.

Another preferred embodiment is to introduce an alloy material with a relatively low melting point at a temperature slightly above its melting point and to feed the high melting point alloy material to the molten slag at a higher temperature; Particular preference is given to using alloy materials as electrode materials or embedding them in molten electrodes. The material dissolved in the molten slag becomes fine-grained crystals upon transfer to the molten metal, and the crystals that settle to the solidification zone form mixed crystals that are strongly bound to this zone.

A device for supplying molten metal which can accurately quantify the supply flow rate and effectively prevent contamination by foreign objects and gases will be described with reference to FIG.

In order to control the apparatus for carrying out the method of the invention, a temperature sensor is arranged in the mold, and a monitor signal from the drive means is fed back to the control device so that the control device performs feedback control on a given basis. to be done.

The present invention will be described in detail below based on embodiments shown in the accompanying drawings.

Special molds or dip molding equipment can be used to produce blocks and hollow blocks using the method of the invention. This apparatus is shown in FIG.

First, the mold Ka is placed in the heating zone H2 in the heating container 50, the mold is filled with molten metal S, and then the hard material particles 3 are filled.
A feed device DV comprising a controllable dispersion device 57 of a is placed above the top surface 56 of the molten metal S.

To cool the molten metal, mold 1 (along with heating zone H)
The boundary 5 between the solidified material 14a and the molten material S is
5 is substantially flat, so that the rate of immersion in the cooling water is equal to the rate of solidification of the molten metal. In this way decomposition is avoided. The embodiment in which the mold is immersed downward, the water level of the cooling water KW surrounding the mold is raised by that amount, and the heating container 50 is lifted in parallel is not limited to the embodiment shown.

As shown in FIG. 2, the time required for the particles to settle or move through the total height hg of the molten material S is determined so that the distribution of the solidified material 14a1, that is, the hard material particles 33a in the manufactured block is uniform. The total amount of hard material is evenly distributed over a total time of 11 and a subsequent cooling time tk. The immersion of the mold Ka begins as soon as the hard material particles reach the bottom 51 of the mold.

FIG. 2 is the timing graph. The line ge shows the position of the boundary 55 with respect to the bottom 51 of the mold, the line d shows the amount of dispersion of hard material particles relative to the total amount hd,
, indicates the height of the addition zone.

Some machine parts made from solidified materials, such as the tip of a drill, are preferably made wear resistant in only a portion. In this case, depending on the position of the addition scene hde, hda in the total height k(l), the dispersion of the hard material is determined in the time slots te, ta for the total time tt+tk, (Figs. 3 and 4). Let's do it.

With this method, the countermovement of the settling of the particles 34a in the molten metal S and the growth of the solidified material 14a is always taken into account.

The dispersion takes a pre-travel time tte before the particles reach the boundary 55,
tta starts earlier.

The embodiment shown in FIG. 3 is more preferable than the fourth embodiment in that the settling time is short and errors are reduced. It is also within the scope of the present invention to add to both ends of the block by superimposing the methods of FIGS. 3 and 4.

It is also possible to add further dosing zones in the vertical direction of the block. These zones can be easily separated in the additive-free cross section.

It is impossible that the distribution of the hard material particles in the horizontal section is not uniform to some extent. For example, the additive concentration may increase in the outer part. Due to turbulent flow, sedimentation is not necessarily vertical, so sideways deviation must be expected.
This offset makes the lateral boundaries of the zone inaccurately defined.

The cross-sectional shape of the mold varies depending on the application. Further, a hollow body can be formed by inserting a core into a mold, and cooling water is passed through this hollow body from below as well as the outer wall of the mold.

Prevents the settling of the hard material particles from being hindered by bubbles generated on the surface 56 of the molten metal S, and prevents air from being mixed into the melt together with the hard material particles 31a, resulting in incomplete bonding of the hard material particles to the matrix. Therefore, the preferred device embodiment includes a protective gas between the dispersion device 57 and the surface 56.
For example, depending on the type of metal, argon, nitrogen, or carbon oxide may be introduced, or a vacuum of several Torr may be generated, which is effective for degassing the melt S. For this reason, mold 1
(An airtight cover 52 having a gas or vacuum supply port 53 is provided between the dispersion device 57 and the dispersion device 57. Preferably, the cover 52
a heating device for the hard material particles 31a passing therein;
For example, a plasma heating device 58 is arranged so that a heating zone HZb is formed directly above the surface 56 of the melt S.

In this heating zone 1-12)b, the surfaces of the hard material particles are heated for a short period of time, so that they become more firmly embedded in the matrix. The control of the dispersion timing with respect to the addition amount and dispersion distribution as well as the travel time and the cooling time is carried out by means that those skilled in the art refer to as a shaker, and for example, as shown in FIG. This is done with a switch. The control circuit detects the boundary 5 of the coagulated material by e.g. a sonar positioning device.
5 is also complemented by closed-loop control means which constantly control the movements of the cooling zone, such as the rise and addition times of the cooling water, accordingly.

Rather than uniformly doped material, variable dosing patterns, for example the formation of multiple dosing zones with gradual transitions, are also possible.

In the method of the present invention, it is also possible to add components other than hard materials to the molten metal in order to improve other properties, such as difficult-to-weld properties and difficult-to-cut properties required for shielding or defense equipment. For example, quartz or corundum can be added to the light metal.

Different types of fillers can be used to achieve different properties, such as tungsten carbide for wear resistance and quartz for fire resistance, each added to the molten metal at the appropriate time. disperse. This provides the novel composite properties of the present invention.

FIG. 5 shows a partially simplified vertical sectional view of a continuous casting apparatus implementing the method of the present invention using electrically heated molten slag as heating zone H2. It is possible to use molds with different cross-sectional shapes while employing the same method.

Furthermore, the illustrated injection/addition device can also be replaced by another one, and the drawing only shows its basic function.

The illustrated mold is made of copper, and the cooling water is connected to the connecting pipe KW1. K
Flows between W2. The horizontal cross section may be circular or rectangular.

For example, when the purpose is to manufacture plate materials, if the depth is much longer than the width in the drawing, as in the case of "1°", several electrodes 13 are placed side by side every few centimeters, and the molten slag 12 is If the bottom of the mold is closed, i.e. without a sampling device Z, it is possible to produce castings that match the shape of the mold.In this case, cooling The mold can be divided into at least two halves for later removal of the casting.

The illustrated mold is for manufacturing round materials, and has a diameter of 30++.
It is normal to be able to produce round materials with a diameter of +m or more. To produce smaller diameter products, the melting space of the molten slag is increased. For this purpose, a steel ring 1 is placed on top of the copper mold.
Place.

By arranging several electrodes 13 in parallel, a flat material, for example, with a cross section of 20
A flat material of 200ml x 200ml can be manufactured. The electrodes oscillate and the hard material 31 is distributed between them. A uniform distribution is thus obtained. The distribution is improved by pendulum motion and a strong magnetic field around the channel. This distribution effect is particularly pronounced when using sintered carbide or hard metal scrap. In this case, the hard metal particles 13 are attracted towards the electrode 13 by the magnetic field. Constantly melting the electrode,
Uniform distribution is achieved by even pendulum movement.

The raw material for rolled products has a cross section of 40x40mm2.50x
50mm2 or 60X 60+111112,
To obtain a consistent material, use at least 2 to 3 electrodes.
3 must be used to make a pendulum movement on a square cross section. Similarly, the hard material particles 31 are dispersed in the molten metal 12 or 53 while making a pendulum movement. If pendulum motion is not applied, slag cavities will occur near the mold wall. When hard material is dispersed in the center of the cross section, a columnar portion of hard material is formed in the center, and cracks are generated in this crystal columnar portion during subsequent rolling.

The manner in which the distribution on the cross section is controlled must be changed depending on the type of carbide used. Molten tungsten carbide tends to settle in the center of relatively deep boundaries;
Sintered tungsten carbide is driven against the mold wall under the influence of a magnetic field.

In this case, the result is a product with particles dispersed on its surface, as is normally desired.

When the cross-sectional area exceeds 70 x 70 mm2, crystal columns are more likely to be formed. Therefore, manufacturing of flat shaped members is extremely easy. FIG. 5 is an example of another cross-sectional shape.

After solidification, the profile leaves the mold in a red-hot state, and its extraction temperature is approximately 900° to 1,000°C. As the slag layer 15 descends from the mold, it first cools down and most of it peels off from the surface.

When melting the matrix material away from the mold, the molten metal S1 passes through the inlet SE and into the slag collection container S.
After being deslagged by the slag remover 21.22 from above and below, it settles into the funnel T through the controllable bottom valve . The funnel is rotationally symmetrical about its vertical axis and has a vertical cross-sectional shape such that the settling molten material S does not rotate and therefore does not entrain air.

The outlet TM of the funnel opens directly above the molten slag 12 located near the enlarged diameter 11 of the mold. The flow rate 323 into the mold is determined by the height h2 of the melt S2 in the funnel T. Therefore, the bottom valve (2) may be controlled by the valve control means VS in accordance with the height h2. However, in the embodiment shown, the weight of the filling funnel (2), which is mounted under springs and is connected to a weight sensor Gm, is constantly measured so that the flow rate 12 into the funnel T is equal to the given outflow rate S23. Note that the outflow amount 323 must be equal to the amount of solidified material extracted in order to proceed with continuous casting in an equilibrium state, and the state in which the molten metal in the mold reaches a predetermined height is set as the desired state. The drawing speed of the extracting device 7 is controlled by a hot water temperature detection signal from a temperature sensor TS3 provided below the mold.

The molten slag 12 is held in the funnel-shaped upper part N of the mold leading to the rim 1, which is not cooled by water inside but only by heat conduction into the mold. The height h of the molten slag is stabilized by mixing slag powder SP into the molten slag 12 using a slag supply device 3d1, for example, a shaker device.

The hard material particles 30 are stored in a container 40 from which a metered amount of particles is extracted by a controllable shaker R at the bottom.
``I9 daughter stream 31 preferably enters the molten slag 12 via a hose 41 and its mouth 42 which reaches in the vicinity of the electrode 31, said electrode 31 being coupled to a vibratory movement device A/P, by which the hose 41 As already mentioned, if the hard material particles 31 are magnetically permeable, they will be held by the magnetic field generated by the current flowing through the electrode 13 and the molten slag 12, and the flow path will constantly move around the magnetic field. ,
The hard material particles are carried by the force of the magnetic field and distributed on the slug surface up to the rim of the funnel-shaped part 11 of the mold. The shape of the funnel-shaped portion 11 together with the height hl from the lower edge of the molten slag 12 limits the distribution of hard material particles 32, 33 and 34 in the cross section of the molten slag 121) molten metal S2 and solidified material 14 be done. For example, increasing the volume of the dowel portion increases the hard material concentration in the zone near the surface.

During such continuous casting, different temperatures are measured at different heights of the mold wall, below the mold wall and at rim 1, and these temperatures influence the height of the slag surface, molten metal surface and, to some extent, the solidification boundary. suggest.

Therefore, temperature sensors TS1. TS2゜TS
3 are connected to a control device ST, and the control device controls the following requirements according to the signals.

1. Slag feed device Sd 21) Material feed flow rate S 23° 13a, 31 in a given ratio to each other, height of the melt S3 3, withdrawal speed of the withdrawal device Z, and 4. Mold K and electrode 13 Power supply m of generator G connected to
0 The electrode 13 is made of a high melting point material, for example tungsten, or is water-cooled from the inside. The electrodes are connected to a pendulum motion or stirring device A/P that moves continuously over the central area of the surface of the molten slag 12 with a period of several seconds, and the electrodes are immersed into the molten slag to about 1/4 or 1/2 of its height. be done.

In another embodiment in which the electrode 13 is made of an alloy material, the pendulum motion device also serves as a feed drive and is controlled in accordance with the required amount of alloy material corresponding to the flow rate S23 of molten material.

A tube filled with alloy material or a phosphate-coated strip may be used to supply the alloy material, and in some cases the entire molten material, through the electrodes. The alloy material is preferably composed of two or three types of alloy materials or crystals so that the melting point of the alloy is much lower than the melting point of the individual materials, and the ratio of the materials is determined depending on the desired alloy composition. For example, ferrosilicon, ferromanganese, ferrochrome,
Ferrous alloys such as ferro-tungsten, or Fe-
3 such as Cr-C, FeFe-8i-, Fe-W-C
Component alloys are used. The carrier material may be unalloyed iron or an iron-based alloy containing chromium or nickel.

The current or voltage of the generator G is set to such a strength that the electrode i13 is melted to an immersion depth of about 1/3 of the height of the molten slag 12. In some cases, only a small amount of alloying material is required, and if the heating current is required to be strong enough to reach a predetermined temperature of the molten slag, a melting electrode and an inert electrode must be juxtaposed.

The control device is a program-controlled processor whose program operates according to the method of the invention. From the output circuit of the control device @ST, control lines Sda,
Vsa, Za, A/Pa.

A control line Qa is connected to the generator G. The power generator 11G may be a controllable transformer with or without a rectifier circuit, or a pulse-controlled generator known in the welding art. When controlling the voltage rather than the current, the negative resistance properties of the molten slag create strong turbulence in the slag, which is in principle an advantageous phenomenon.

In the control method of the present invention, the sampling temperature, slag height,
Working conditions such as molten metal height, alloy material ratio, pendulum motion amplitude, slag temperature, etc. are entered into the control device ST via an input device E, for example a keyboard. The operating parameters and the deviations from the reference values are provided via an output device, for example a display or a printer. The drive device and container for the molten metal fis1, the slag powder SP1 hard material particles and electrodes, and the cooling water tank are provided with appropriate sensors that transmit their respective states to the control device, ST, via the monitor line RM.

In order to control the timing of starting and stopping, a control device W
ST is connected to a clock CL, and the clock signal determines a time constant for bringing the melting device into equilibrium according to a specific program. When operating a particular mold for the first time, the operator takes direct control, enters a set of working conditions and records the operating parameters actually given by the signals. In subsequent operations, the measured operational parameters are used as reference values for feedback control, and the deviations of the measured signals from the recorded parameters are used to control each control means such as the drive device, valves, etc. described above. For example, similar control is performed even when work is temporarily stopped to replace parts or refill materials.

The temperature of molten slag is between 1,700°C and 2,000°C when using tungsten carbide or hard metal scrap.
0°C is preferred.

The slag powder may be composed of, for example, the following mixture.

- 45% silicon oxide and titanium oxide, 10% calcium oxide and magnesium oxide, 40% aluminum oxide and manganese oxide, 5% calcium fluoride, or 35% silicon monoxide, 20% magnesium oxide, 25% aluminum oxide, fluoride Calcium chloride and other 10% The temperature at which the material is withdrawn from the mold K must be approximately i, ooo'c, ie always below the melting point of the matrix material used. In order to melt the hard material particles 32 in the molten slag 12 only on their surfaces, the supporting gage height and the slag temperature must be set correctly in relation to the time required for the particles to move through the slag. Refining and particle shape and specific gravity for the molten slag 12 are parameters to be considered along with the viscosity of the slag. The average standard height of the slag is 4 cm.

FIG. 6 is an electron microscope enlarged cross-sectional view of a matrix material sample containing a large amount of chromium and using tungsten carbide as the hard material. The hard material H1 is tightly surrounded by a diffusion zone D1 several micrometers deep. The matrix material M1 contains a low concentration of dendritic structures D2 of hard material forming branches approximately 1 micrometer thick. The spaces between the dendritic structures 02 are completely filled with matrix material. Figure 7 contains about 0.18% carbon, WC+Ta C+Ti
5T37 added with sintered hard metal particles H2 consisting of C
-2 is a low magnification cross-sectional view of a matrix material of non-alloy steel. No diffusion zone is visible on the inside, but this is because the magnification is lower than in Figure 6.

Dendritic zone D20 extends approximately 100 micrometers into the matrix material from particle H3.

A low concentration hard material diffusion zone D30 extends beyond the dendritic structure for a further 30 micrometers, and pure matrix material M2 is visible outside this zone.

It is also possible to apply the manufacturing method of the present invention in a mold consisting of two halves with a closed bottom, filling it with molten hot slag at the start of production, then filling it with molten metal, and heating the slag with an electric current while applying the electrodes. Add the hard material particles through.

This method allows the manufacture of chisels, drills, drill heads, scraper blades, plow blades, etc. without machining.
Depending on the application, the addition can be particularly limited to the outer surface or cutting edge. The controller starts, stops, and controls the drives and valves with respect to their respective timing and amounts according to a program created to properly control the individual melting processes.

If the hard material particles 31 are added in advance to the electrode material together with the alloy components in the required proportions, the control device and processing device can be simplified. In this way, there is no need to separately provide the hard material supply device R and the container 40.

When processing negative alloys and additives in the same processing equipment, different types of electrodes must be prepared.

By using a variety of electrodes together, a wide range of materials can be processed with a limited number of electrodes.

It is also possible to feed the strip containing the alloy material into the molten slag without being connected to the generator. In that case, melting energy is extracted locally from the slag, resulting in
A local temperature drop occurs, which can be used to advantage. The reason is that temperature distribution affects crystal phenomena.

A person skilled in the art can analyze this effect by analyzing a cross-section of the material produced.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of the immersion casting equipment, Figures 2 to 4 are timing graphs of the hard material addition block and additive cooling;
Fig. 5 is a partially simplified vertical cross-sectional view of the continuous casting device, Fig. 6 is an enlarged cross-sectional view of hard material particle boundaries under an electron microscope,
FIG. 7 is a cross-sectional view similar to FIG. 6, but at a lower magnification, and FIG. 8 is a table showing the chemical composition of preferred martensitic alloys in order of hardness. Patent Applicant Vualnal Schatz Patent Attorney Satoru Yoshimura Engraving of the drawing (no changes to the content) Z Fig, 1 1, Indication of the case 1939 Patent Application No. 227623 25) Title of the invention Embedding of hard metal particles 3, a method for manufacturing metal blocks, castings or shapes, and instructions therefor;
Relationship with the case of the person making the amendment Patent applicant address Federal Republic of Germany, 6119 Karlsba Kashi, Kalbak 81,.
7""7T~5・Supplementary 1 life'? j (7) 84″I
7W60'Mon'°B3 shots "8), -〇, subject to correction
Power of attorney, drawing 7, contents of amendments: The power of attorney, the same translation, and the engraving of p.

Claims (26)

[Claims] (1) The molten metal S3, 5 is transferred from the upper heating zone HZ, HZa, HZb to the lower cooling zone KW, preferably cooled with water, at such a rate that the solidification of the molten metal S3.5 is preceded. A method for manufacturing metal blocks, castings or profiles 14, 14a from a hard material 31, 31a consisting of powder, particles or crystal grains from an upper heating zone HZ, HZa, HZb during a cooling period. 31, molten metal S3 at a temperature below the melting point of 31a,
A method characterized in that the method is characterized in that it is distributed over and dispersed within the surface 56 of 5. (2) The temperature of the heating zones HZ and HZb is the hard material particle 3
1,31a, characterized in that the particles, before entering the molten slag, pass through a heating zone HZ, HZb at such a speed that the particles melt to a depth of about 1 micrometer from the surface. A method according to claim (1). (3) The method according to claim (2), characterized in that the heating zone HZb contains a plasma furnace in a protective gas atmosphere consisting of, for example, an inert gas. (4) Molten slag 1 in which the heating zone HZ is heated to a temperature higher than the melting point of the hard material particles 31 and 32 by electric resistance heating.
2, the height h of which is set so that only the surface of the hard material particles 32 is melted. (5) The height of the molten slag is 1 to 5 cm, the slag temperature is 1,700°C to 2,000°C, and the composition of the slag is: - 45% silicon oxide and titanium oxide, 10% calcium oxide and magnesium oxide %, aluminum and manganese oxides 40%, and calcium fluoride 5%, or - 35% silicon oxide, 20% magnesium oxide, 25% aluminum oxide, calcium fluoride and 10% other. The method described in item (4). (6) connecting a power source to the mold K, preferably made of an inert material, for example tungsten, cooled and swinging or rotating in the central area of the slag surface to approximately 1/1/2 of the depth of the molten slag S3; It is also connected to the electrode 13 which is immersed in the slag by 4 or 1/2, and preferably supplies hard material particles 31 near the electrode 13 as the electrode 13 swings or rotates. A method according to claim (5). (7) While connecting a power source to the mold K, it is connected to an electrode 13 made of metal that is continuously melting in the molten slag 12, and this electrode 13 is a molten metal S23 that is separately supplied into the slag 12. and the molten metal 5 in the mold K of the desired composition.
3 or at such a rate that the solidified material 14 is obtained, and the electrode 13 is 1/4 to 1/2 of the height h of the slag.
5. The method according to claim 5, wherein the amount of power supplied or the slag temperature is set so that the slag melts at a depth of 100 to 100 ml, and the electrode is oscillated or rotated in the central region of the slag surface. (8) The electrode 13 is formed of a tube or a strip material, and the alloy components of the molten metal S3 and hard material particles, such as tungsten carbide, are fixed to this electrode, and the melting point of the hard material particles is lower than the temperature of the molten slag 12. low, molten metal S3
Claim 7 characterized in that the temperature is higher than the temperature of
The method described in section. (9) withdrawing the solidified material 14 from the molten metal S3 from the cooling zone at the same rate as the solidification rate and, corresponding to this withdrawal, creating a molten metal flow S23 into the melt S3 with a melt height of approximately 2 to The method according to claim (1), characterized in that the distance is controlled to be 10 cm. (10) Transfer the molten metal S1 from the melting device to the slag collection container S
F into the funnel T through a controllable bottom valve V from the vessel.
feed the molten metal S3 in the mold into the mold through and maintain a constant material flow S23 by controlling the valve V in feedback mode depending on the height h2 or weight of the molten metal S2 in the funnel T for a given value. The supply and withdrawal temperature is approximately 1,
A patent characterized in that the solidified material 14 is extracted from the bottom side of the mold K at a rate such that the temperature reaches 000°C, and the supply rate and feed rate of the hard material particles 31 and the electrode 13 are set in proportion to this extraction rate. The method according to claim (9). (11) The travel time tt required for the hard material particles to settle the total height hg of uncooled molten metal, and the cooling time tk required for cooling the total height hg of the blocks in the mold Ka at a constant rate. The height hd, hd of the zones Zg, Ze, Za to be added in the blocks Bd, Be, Ba
Claim No.
The method described in section 1). (12) Hard material 3 consisting of powder, particles or crystal particles
1a by means of a sieve or preferably by wind or liquid into parts of equal settling velocity and feeding each part to the molten metal S taking into account the respective travel time tt which limits the time interval of addition. The method according to claim (11). (13) Hard material 3 to molten slag 12 and molten metal S
1. Process according to claim 1, characterized in that the dispersion of 1,31a is carried out in vacuum or in a protective gas, for example an inert gas atmosphere. (14) In the apparatus for carrying out the method according to claim (4), the mold K has a space on the top of the molten metal S3 to accommodate the molten slag 12 having at least a height h. , this space preferably extends in the form of a funnel 11 to a rim 1, preferably made of steel, and the mold K itself is preferably made of copper and is cooled by running water, and the height h1 of the molten slag 12 is controlled by a reciprocating device or A device characterized in that it is set such that a given horizontal hard material addition pattern occurs in the solidified material 14 in relation to the maximum amplitude of the rotation device. (15) Exit T of the molten metal supply device above the slag surface
M, a slag powder supply device Sd and a holder for the electrode 13 attached to at least one, preferably supply/reciprocating device A/P, and a hard material supply device 40, 41, 42, R are placed under the mold K. The apparatus according to claim 14, characterized in that a sampling device Z is disposed at. (16) The molten metal supply device is composed of a slag recovery container SF having a controllable bottom valve V, a funnel T having an outlet TM is arranged below the slag collection container SF, a weight sensor Gm is provided on the funnel T, and the signal thereof is The signal is supplied to a regulating device forming a part of the control device ST, and in the regulating device the signal is applied to the coagulating material 1.
Compared with the value proportional to the solidification rate or withdrawal rate of 4,
16. The device according to claim 15, wherein the output signal of the regulating device is supplied to control means for the bottom valve. (17) Input from control device ST to weight sensor Gm, rim 1
, temperature sensors TS1...TS3 provided on the inner wall of the mold and the material 14 taken out from the mold, monitor contacts or sensors of the valve control device VS, feeding and reciprocating device A/P, slag feeding device Sd, hard material feeding device Control signal lines VSa, A/Pa, Sda, Za, Ra, and Gs are connected to R, generator G, and sampling device Z, and the outputs are used to control the respective drive means or the current or voltage of the generator G. By connecting and applying a clock CL to the control device ST, the method is performed in conjunction with the program contained in the control device and the parameters given via the input device E, and the deviations from the specified parameters are detected by the output device. A, and the height of the molten slag 12 is controlled by the slag supply device Sd using the signal of the temperature sensor TS1 provided on the rim 1, and the current or voltage of the generator G is controlled. Temperature sensor T installed on the mold wall
Using the signal S2, the height of the molten metal S3 is controlled by the molten metal supply device, and the supply of the dispersed hard material is controlled, and the time constant of the device is corrected by the control described above. The device according to claim (16), characterized in that: (18) The control device ST controls the hard material supply device R in accordance with the timing of sampling performed by the sampling device Z, and controls the hard material flow rate in accordance with the molten metal flows S23 and 13a. Claims characterized in that the amplitude, position, and movement timing of the reciprocating and rotating device A/P are controlled so that zones with different hard material concentrations are generated in the vertical and horizontal directions such that the hard material concentration increases. The device according to paragraph (17). (19) Consisting of an immersion mold Ka, with a dispersion device 5 above it.
7 is attached, and the dispersing device disperses the hard material particles 31a onto the surface 56 of the molten metal S in the mold Ka while controlling the flow rate and timing thereof. Apparatus for carrying out the described method. (20) coupling the dispersion device 57 and the mold Ka so that a vacuum is maintained by the cover 52, and connecting the internal space defined by the cover to an inert gas or vacuum source;
The device according to claim 19, characterized in that the internal space is a heating zone HZb, in which preferably a plasma heater 58 is arranged. (21) In a casting or profile manufactured according to the method according to any one of claims (1) to (13), a diffusion zone with a depth of 0.3 to 3 micrometers. Hard material particles H1 surrounded by D1 without any gaps,
H2, for example tungsten carbide, with a matrix material diffused into the particles over said 0.3-3 micrometer depth, and around said diffusion zone D1 a low layer of about 1 micrometer thick. There is a zone D2, D20 containing a volume concentration of hard metal dendritic structures, the depth of said zone D2, D20 being 100-300 micrometers, reaching a depth of about 50 micrometers outside this zone. Casting or profile, characterized in that there is a hard material diffusion zone D30 with a low concentration, and the spaces between said dendritic structures, diffusion zones etc. are completely filled with matrix material M2. (22) The cast or shaped material according to claim (21), wherein the content of the hard material is 8 to 25% by weight relative to the matrix material. (23) Casting or profile according to claim 22, characterized in that the concentration of hard material on the outer surface, in particular in the zone close to the working surface or the cutting edge, is several times the average concentration of the whole. . (24) A patent claim characterized in that the diameter of the hard material particles is set to 0.3 to 0.8 mm for applications subject to rolling and impact stress, and 0.8 to 4 mm for applications subject to cutting or friction stress. The cast or shaped material according to item (21). (25) The matrix material is - a low alloy steel containing - 0.8-1.8% manganese and about 1% silicon or - a martensitic steel or - for example - 18% Cr, 8% Ni or - 19% Cr, 9% Ni and Mo Or an austenitic steel containing -Cr18%, Ni8%, Mn6% or -C1.2%, manganese steel containing Mn12-17% or -C1%, Si1.8%, Mn17%, Cr17%, W
3.5% of nickel or an alloy with a high nickel content. (26) The matrix material is a non-ferrous alloy, preferably AC
Mg3, AC Mg5, AC Si5, AC Mg
Casting or profile according to claim 21, characterized in that it is Zn1 and the hard material particles are metal carbides or oxides, such as colangum.