JPS5992020A - Non-oxidative heat treatment apparatus - Google Patents

Abstract

PURPOSE:To reduce the consumption amount of reductive gas and to enable uniform non-oxidative treatment over the whole surface of an object to be treated, by sufficiently cover the surface of the object to be treated with active reductive gas by reducing the internal volume of a treating chamber. CONSTITUTION:In performing non-oxidative heat treatment such as high temp. carburization by using high frequency heating, an object 6 to be treated is hermetically sealed and a high frequency heating coil 2 and a shielding plate 3 made of a non-metallic material are arranged to the side surface of the object 6 to be treated to constitute a treating chamber 5. Reductive gas supplied from the lower part of the treating chamber 5 is blown to the object 6 to be treated from a blow-out port 8 provided to side surface of the object to be treated to treat the same. By this mechanism, because the inner volume of the treating chamber 5 can be reduced and the surface of the object 6 to be treated can be sufficiently covered with active reductive gas, the whole of the object to be treated is uniformly subjected to non-oxidative heat treatment and the amount to be used of the reductive gas required in heat treatment is remarkably reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-oxidizing heat treatment technique, particularly to a method of introducing a reducing gas for non-oxidizing heat treatment using high frequency heating, and an apparatus therefor.

Conventionally, limb treatment materials are subjected to non-oxidation heat treatment using high frequency heat treatment as one of the high temperature heat treatments.

The heat treatment was carried out using an apparatus as shown in FIG. In the conventional apparatus, the processing chamber 7' is installed with a distance of 100 mm or more from the frequency heating coil 2' to the processing chamber side wall 1'. In addition, 3' is the object to be treated, and 4' is the reducing gas insertion 1.

5' is a reducing gas outlet.

Here, in order to prevent the steel furnace body 6' from being dielectrically heated,
Using a large processing chamber 7', the frequency heating coil 2' and the object to be processed 3' are housed in the processing chamber 7', and after replacing with an inert gas such as nitrogen gas or a reducing gas, high frequency heating is performed. Heat treatment is carried out under the required conditions, but because the processing chamber 7' is large, it takes a long time to replace the scum with inert scum, etc., and the gas consumers such as inert scum are large. There are drawbacks.

In addition, when non-oxidizing heat treatment is performed in this processing chamber 7', in order to perform uniform non-oxidizing heat treatment over the entire length of the object 3', it is necessary to insert a large amount of oxidative gas into the object 3'.
'There is also the drawback that there is insufficient active gas on the surface, resulting in uneven processing.

An object of the present invention is to provide a heat treatment apparatus that reduces the amount of gas consumption such as reducing gas when performing non-oxidation heat treatment using high-frequency heating, and uniformly performs non-oxidation heat treatment on a workpiece 3'.

The purpose of this is to seal the object to be treated and place a high-frequency coil and a non-metallic material on the side of the object when performing non-oxidizing heat treatment such as high-temperature carburizing using high-frequency heating. This is achieved by a non-oxidation heat treatment device, which consists of a non-oxidizing heat treatment device, which is characterized by blowing reducing gas, which is inserted from the inside of the processing chamber, onto the object from an outlet provided on the surface of the object to be processed. .

The present invention will now be described in detail based on the accompanying drawings.

FIG. 2 shows an example of the non-oxidation heat treatment apparatus according to the present invention. It is surrounded by the ceiling and bottom, and the sides are covered with high-frequency heating coils and non-metallic materials f! A gas shielding plate 3 of 4 (for example, ceramic) is provided to form a two-chamber structure in which the processing chamber 5 is isolated from the empty chamber 4, and reducing gas is inserted only into the processing chamber 5.

In addition, in order to sufficiently cover the surface of the object to be treated 6 with active reducing gas and perform a uniform non-oxidation treatment on the surface of the object to be treated 6, the gas hole 8 on the inner circumferential surface of the high frequency heating filter 2 or the A non-oxidizing heat treatment is carried out by performing high frequency heating under required conditions while blowing a reducing gas onto the surface of the object 6 from a nozzle 7 provided near the object 6.

Note that the inside of the processing chamber 5 is isolated from the empty chamber 4 by having a two-way structure, and reducing gas is blown from the inward gas hole 8 or nozzle 7 of the high-frequency heating coil 2.

Since the non-oxidizing heat treatment is performed, the amount of carrier gas from the insertion point 8 can be significantly reduced compared to conventional equipment.

- For example, carry out the specified carburizing and quenching! The consumption amount of carburizing gas required for rice is shown in Table 1.

Table 1 Gas consumption in carburizing and quenching It is understood that the carburizing gas required to carry out the specified carburizing and quenching process is reduced to 1/10 by using the device of the present invention compared to the conventional device. Ru.

In addition, if the insertion rate of carburizing gas is reduced to a level suitable for carburizing with the device of the present invention in a conventional device, uneven carburizing occurs as shown in Fig. 3, and the carburizing and quenching required in 191 cannot be performed.
3 shows the appearance and part (curved part) of the carburized specimens carburized by the conventional device and the device of the present invention under the same carburizing gas injection conditions.

In the figure, 1 and 1' are cross-sections with no carburization, and 2 is uneven carburization.

3 and 3' are areas where the surface is recognized to have been uniformly carburized.

In addition, in this example, in order to ensure a complete gas seal, 2.
Although it is a Mh'4 structure, it is not an essential condition for the present invention to have a two-chamber structure.

The specimens carburized by the apparatus of the present invention were uniformly carburized, whereas the specimens carburized by the conventional apparatus clearly showed the presence of uneven carburization both from surface observation and cross-sectional observation.

As is clear from the above, according to the apparatus of the present invention, the processing chamber 5
The inner volume of the workpiece can be significantly reduced, and the surface of the workpiece 6 can be sufficiently covered with active reducing gas, so not only can the entire workpiece be uniformly heat-treated without oxidation, but the reducing gas required for the heat treatment can also be used. The advantage is that the amount can be significantly reduced.

[Brief explanation of drawings]

Figure 1 shows a conventional circumferential heating non-oxidizing heat treatment equipment. Figure 2 shows an example of the high-frequency heating non-oxidation heat treatment apparatus according to the present invention, and Figure 3 shows the apparatus of the present invention under positive conditions. An example of a treated product carburized using a conventional device and a device u of the present invention is shown. 2... High-frequency heating coil, 3... Shielding plate made of non-metallic material, 5... Processing chamber, 6... Workpiece, 7... Nozzle. 8... Gas hole in the inner circumferential direction of the high-frequency heating coil, 9...
Carrier gas insertion port, 10...Gas exhaust port
Person Toyota Motor Corporation Figure 1 Figure 20 Oshiba Kaze Ao Award sire J Rishina Hon' is Sun Moon Shi' Treatment I
Satoichi Figure 3 Procedures Amendment (Method) % Formula % (7. Indication of fact 1982 Patent Application No. 201751 2. Title of invention Non-oxidation heat treatment device 3. 1. Case to be amended Related Patent applicant address: 1 Yota-cho, Toyota City, Aichi Prefecture 4714,
Daily publication of amendment order February 2, 1982 (Shipped ffFebruary 22, 1982)
5. Figure 3 of the coffin i positive object

Claims (1)

[Claims] When performing non-oxidation heat treatment such as high-temperature carburizing using high-frequency heating (hereinafter simply referred to as non-oxidation heat treatment), a
The processing chamber is configured by sealing the processing object and arranging a high-frequency heating coil and a non-metallic material on the side surface of the processing object,
The process is characterized in that the reducing gas (hereinafter simply referred to as reducing gas), which is inserted from the side of the processing chamber, is sprayed onto the processed object from a blow-out provided on the surface 611j of the processed object. Oxidation heat treatment equipment.