JPS60243261A - Ionic application multipurpose heat treatment and apparatus - Google Patents

Abstract

PURPOSE:To perform the ionic carburizing treatment necessitating high temp. and the ionitriding treatment treated at low temp. by means of the same apparatus by making double walls having through-holes of the peripheral wall of a vacuum heating furnace in an ionic application heat-treatment apparatus and performing the adjustment of the temp. of the inside of the furnace with the opening and closing of the through-holes. CONSTITUTION:The material 18 to be treated is put on a cathode jig 34 of the inside of a vacuum heating furnace 16 provided with a vacuum pump 30 and the surface treatment is performed by causing glow discharge between an anode 36 and the cathode. In this case, ionitriding and ionic carburizing treatments are performed on the surface of the material 18 to be treated by introducing gaseous nitrogen or gaseous hydrocarbon from a gas introducing pipe 24. Since the ionitriding treatment may be performed at the low temp. of 400-600 deg.C, the through-holes 49 of inner wall 44 are allowed to coincide with the through-holes 51 of outer wall 46 to lower the temp. of the inside of the furnace by moving the outer wall 46 of double walls provided to the surrounding. In case of the ionic carburizing, the through-holes of inner and outer walls are closed by moving the outer wall 46 and the inside of the furnace is elevated to 900-1,050 deg.C with a heater 40 to perform the ionic carburizing treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion-applied multi-purpose heat treatment method and apparatus, and more particularly to an ion-applied multi-purpose heat treatment method and apparatus that can effectively handle both high-temperature treatment and low-temperature treatment in the same furnace. .

Regarding.

, N2 (nitrogen) and C3H in the atmosphere due to glow discharge.
A surface heat treatment method in which a gas such as a (hydrocarbon) is ionized and permeated and diffused into the object to be treated by ion bombardment.
Ionic carburizing, ionic nitrogen.

or CV D (Chemical Vapor
It has great potential for application to the surface technology (deposition) method and future development of surface technology, and manufacturers are progressing in adapting it to mass production.

The feature of heat treatment using this ion bombardment is that it efficiently ionizes a dilute gas, causes it to collide with the surface of the object to be treated, and at the same time allows atoms such as C and N to permeate and diffuse.
In addition, strong oxidizing atoms such as 02 do not exist in the furnace, so grain boundary oxidation does not occur on the iron surface, and there is no need to burn exhaust gas, so the furnace does not become dirty and the surrounding environment is good. There are benefits.

However, the currently available ion carburizing furnaces and ion nitriding furnaces are used individually for the treatment and are not shared. Therefore, in a multi-model, small-volume production line, it is necessary to install at least two types of furnaces: a low-temperature processing furnace used for ion nitriding, etc., and a high-temperature processing furnace used for ion carburization, etc. There were problems such as the considerable financial burden of investment and the fact that the two types of furnaces occupied a vast space, making it difficult to make effective use of the factory space.

Given this background, if carburizing, nitriding, standardization, and thermal refining could be performed in one furnace, it would be possible to overcome the above-mentioned difficulties, but in order to realize this, there is a separate issue of how to balance the heat of the workpiece. Different problems were pointed out.

In other words, when performing ion carburization, the temperature is 900 to 1050°C.
In order to utilize a very high temperature range, it is necessary to insulate the heat radiated from the object to be processed or the heater, so in addition to insulating the furnace wall, an insulating wall is installed around the object to block the heat. We are working to save energy and keep the materials being processed warm. On the other hand, in ion nitriding, 400 to 60
Processing is carried out at a relatively low temperature of 0℃, but since the temperature of the processed material tends to rise due to ion bombardment, forced cooling treatment such as water cooling of the furnace wall is performed to absorb heat to balance the heat. The structure is such that it can be done. Therefore, when nitriding is performed in an ion carburizing furnace, the heat is not uniformly heated at each location due to the presence of the heat insulating wall, resulting in variations in the nitrided layer, which is unfavorable in terms of quality. Conversely, when attempting to carburize in an ion nitriding furnace, the water-cooling structure of the furnace wall, etc. slows down the rate of temperature rise of the workpiece, making temperature control difficult and reducing the thermal energy during soaking. As the size increases, the thermal conditions of each component worsen, which is not preferable for mass production.

The present invention was proposed taking these circumstances into consideration,
The object of the present invention is to provide an ion-applied multipurpose heat treatment method and apparatus that can effectively handle both high-temperature treatment and low-temperature treatment in the same furnace.

In order to achieve the above object, the present invention provides an ion processing system in which an anode and a cathode are opposed to each other in a vacuum furnace, and a glow discharge is generated between these electrodes to heat-treat the object. The heat treatment is performed by controlling the opening and closing of the heat insulating wall in accordance with the object to be treated and adjusting the atmospheric temperature within the heat insulating wall.

In addition, in order to carry out the method, the present invention further provides an ion processing apparatus in which an anode and a cathode are placed as opposite electrodes in a vacuum furnace, and glow discharge is generated between these electrodes to heat-treat the workpiece. a heat insulating wall surrounding the object to be processed is provided inside, and the heat insulating wall is engaged with a drive device;
The heat insulating wall is configured to be displaced under the bias of the drive device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will now be described in detail with reference to the accompanying drawings, with reference to preferred embodiments and apparatus for carrying out the method.

FIG. 1 and FIG. 2 are an overall configuration diagram and a sectional view of essential parts of a heat treatment apparatus according to the present invention.

In FIG. 1, reference numeral 10 indicates a heat treatment apparatus main body, and this heat treatment apparatus main body 10 includes a sample moving stage 12 including a roller conveyor 12A, and an oil cooling chamber 1 including a lift device 14A.
4, a heating chamber (vacuum furnace) 16, etc., which will be described later. Note that reference numeral 18 indicates the object to be processed, and reference numeral 20 indicates a gas cooling fan provided in the oil cooling chamber 14.

On the other hand, as shown in FIG. 2, the vacuum furnace 16 is formed into a sealed cylindrical body with a circular cross section, and the tip of a gas introduction pipe 24 enters into the furnace chamber 22 thereof. A valve 26 is interposed in the gas introduction pipe 24 . Further, an exhaust pipe 32 faces the furnace chamber 22, a valve 28 is interposed in the exhaust pipe 32, and a vacuum pump 30 is connected to the exhaust pipe 32.

Next, a jig 34 is provided at the center of the furnace chamber 22 for placing the workpiece 18 thereon. This jig 34 is
In this case, it also serves as an electrode as a cathode. Further, inside the furnace chamber 22, an electrode 36 consisting of a columnar anode is arranged so as to cover the object to be processed 18 from above in FIG. The jig 34 and the anode 36 are connected to the furnace wall 1 of the vacuum furnace 16 at their rounded rear ends 34A and 36A.
It is supported through 6A. Of course, the rear ends 34A and 36A of the jig 34 and the anode 36 are connected to a high voltage power source 38.
electrically connected to each.

Furthermore, a heater 40 and a heat insulating wall 42 located outside the heater 40 are provided in the furnace chamber 22 so as to surround the jig 34 and the anode 36.

The heat insulating wall 42 is open at both ends and has a rectangular cylindrical shape with a substantially square cross section, and its four wall surfaces are respectively connected to the inner wall 4.
It is composed of double walls consisting of walls 4a to 44d and outer walls 46a to 46d. In this case, the inner walls 44a to 44d and the outer walls 46a to 46d each have a diameter of 1
A plurality of through holes 48 and 50 of 00+am are formed.

Preferably, the number of through holes 48 and 50 to be formed is selected so that the opening ratio of each wall surface is 50%.

Further, the outer walls 46a to 46d are free to slide in a predetermined direction as described later, so that the through holes 4 in the inner walls 46a to 46d and the outer walls 46a to 46d
The opening area of the heat insulating wall 42 formed between 8 and 50 is controlled to increase or decrease. In this embodiment, the outer walls 46b and 46d, which are the left and right wall surfaces in FIG.
G and 52d for displacement in the front-rear direction. Of course, all four outer walls 46a to 46d may be slid in the front-rear direction. Moreover, the hydraulic cylinder 52a
The stays 54a to 54 d are connected to the furnace wall 16A.
Furthermore, seal members are provided on the furnace wall 16A at portions through which the piston rods of the hydraulic cylinders 52a to 52d pass. Note that the heat insulating wall 42 is appropriately supported using a jig 34, a columnar electrode 36, and the like. Note that reference numerals 49 and 51 are holes for gas flow when the heat insulating wall 42 is closed.

The vacuum furnace 16 according to the present invention is basically constructed as described above.Next, the operation when performing ion nitriding using the vacuum furnace 16 will be explained.

In the vacuum furnace according to the present invention, the object to be processed 18 is first sent from the sample moving stage 12 to the vacuum furnace 16 via the oil cooling chamber 14 . After being subjected to appropriate surface heat treatment in the vacuum furnace 16, the workpiece 18 is returned to the oil cooling chamber 14, where it is cooled by being immersed in low-temperature oil via the lift device f14A.

After cooling, the object to be processed 18 is returned to the sample moving stage 12 and the heat treatment is completed.

This is the basic operation.

Therefore, the workpiece 18 is set on the jig 34 in the process described above. At this time, the opening area of the heat insulating wall 42 is determined by the through holes 48 and 50 is not communicating and is in a fully closed state.

Next, the vacuum furnace 16' is depressurized to 10' to 10-3 Torr through the exhaust pipe 32 equipped with the vacuum pump 30, and then N2+H2 gas is introduced through the inlet pipe 24, and the furnace internal pressure is reduced to 0.5 The pressure is maintained at about 10 Torr.

After that, when a voltage of several hundred μ is applied between the cathode (jig) 34 and the columnar anode 36 via the power supply 38, a glow discharge is generated on the surface of the workpiece 18, and ionized N2
The gas bombards the surface of the workpiece 18 with high energy, and the workpiece 18 is heated to begin nitriding. At this point, the hydraulic cylinders 52a to 52d are automatically driven by a control means (not shown), and the heat insulating wall 42 is
The outer walls 46a to 46d slide in the direction in which the inner walls 44a to 44d and the through holes 48 and 50 of the outer walls 46a to 46d communicate with each other, the opening area of the heat insulating wall 42 is increased, and heat radiation begins. By changing the degree of opening and closing according to the loading amount of the objects 18 to be processed, it is set within a range that is most effective for uniform temperature distribution and energy saving.

Note that if the heat conduction at low pressure is 0.5 Torr or more, there will be no major change and the temperature control effect of the present invention will be fully exhibited, but in the range of 10-2 to 10-Torr, it will enter the high vacuum insulation region. The effect is reduced. However, the vacuum furnace 16 of the present invention has a temperature of 0.5 to 20 T.
There is no problem because it is operated at orr level.

On the other hand, when performing ion carburization using the vacuum furnace 16, the outer walls 46a to 46da of the heat insulating wall 42 are slid in a predetermined direction, and the inner walls 44a to 44d and the outer wall 46a are constantly moved.
If the through holes 48' and 50 of 46d to 46d are kept in a state where they do not communicate with each other, and during this time heated by the heater 40, the ambient temperature of the workpiece 18 can be quickly raised to, for example, 900°C, and ion carburization can be carried out. can be carried out effectively. Of course, only hydrocarbon gas such as CH3 or c3H3 is introduced into the vacuum furnace 16 through the introduction pipe 24.

Furthermore, as an effect of opening and closing the heat insulating wall 42, when lowering the temperature to the quenching temperature after carburizing in high-temperature treatment, it is possible to radiate heat and lower the temperature in a short time, which has the advantage of shortening the total time of one cycle. can.

Next, FIG. 3 shows another embodiment of the present invention.

In this case, as a means for increasing or decreasing the opening area of the heat insulating wall 42, the heat insulating wall 42 is constructed in a single layer, and the two walls 56a and 56b, which are the left and right wall surfaces in FIG. Rotatably supported via
Furthermore, the cylinder rods 5 of the hydraulic cylinders 52e and 52f
The tips of 5e and 55f are connected to the walls 56a and 56b, respectively.
It is attached to the top of the. That is, this is an example configured to open and close like a door via hydraulic cylinders 52e and 52f.

Therefore, gas when the heat insulating wall 42 is in a closed state.

flows into and out of the wall through conduits 55a and 55b, and the temperature is controlled by the wall 5 under the pressure of the cylinders 52e and 52f.
6a and 56b are tilted. As a result, the same temperature control effect as the vacuum furnace 16 shown in FIG. 2 can be obtained.

As explained above, according to the present invention, heat treatment is performed by controlling the opening and closing of the heat insulating wall surrounding the workpiece in a vacuum furnace as appropriate depending on the processing purpose, so that heat treatment can be performed effectively in the same furnace. Low-temperature treatments such as ion nitriding and high-temperature treatments such as ion carburization can be performed, resulting in the reduction of equipment investment and effective use of production line space. - Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various improvements and changes in design are possible without departing from the gist of the present invention. Of course words.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a heat treatment system according to the present invention, FIG. 2 is a cross-sectional view of the main part configuration of the system in FIG. 1, and FIG. 3 is a main part configuration of another embodiment of the heat treatment system according to the present invention. FIG. 10...Heat treatment apparatus body 12...Sample moving table 12A...Roller conveyor 14...Oil cooling chamber 14A...Lift device 16...Heating chamber (vacuum furnace) 16A...Furnace wall 18...Workpiece 20.
・Gas cooling fan 22・・Furnace chamber 24・・Gas introduction pipe 26・・Valve, 30・・Vacuum pump 32・・Exhaust pipe 34・・Cathode (jig) 34A・・Rear end part 36・・Anode 36A・- Rear end 38... High voltage power supply 40... Heater 42... Insulating wall 44a to 44d... Inner wall 46a to 46d... Outer wall 48 to 51... Through hole 5.2 a to 52f... Hydraulic cylinder 54a to 54d... stays 55a, 55b -- through holes 56a, 56b .-
Wall patent applicant Honda Motor Co., Ltd.

Claims (4)

[Claims] (1) In an ion processing system in which an anode and a cathode are opposed to each other in a vacuum furnace and a glow discharge is generated between these electrodes to heat-treat the object, a heat insulating wall surrounding the object is attached to the object. A multipurpose heat treatment method using ions, characterized in that heat treatment is performed by controlling opening and closing in a corresponding manner and adjusting the atmospheric temperature within the heat insulating wall. (2) In an ion processing apparatus in which an anode and a cathode are opposed to each other in a vacuum furnace and a glow discharge is generated between these electrodes to heat-treat the object to be processed, a heat insulator surrounding the object to be processed is provided inside the vacuum furnace. 1. A multi-purpose heat treatment apparatus using ions, comprising: a wall; the heat insulating wall is engaged with a drive device; and the heat insulating wall is displaced under the bias of the drive device. (3) In the device according to claim 2, the heat insulating wall is composed of a double wall including an inner wall and an outer wall each having a through hole, and one of the walls is slidable. A multi-purpose heat treatment device using ions with an opening formed by. (4) An ion application multi-purpose heat treatment apparatus according to claim 2, wherein the heat insulating wall defines an opening by tilting.