JP4354371B2 - Metal material surface modification heat treatment equipment - Google Patents

Description

  The present invention relates to a surface reforming heat treatment apparatus for a metal material, and more particularly to a surface reforming heat treatment apparatus for a metal material in which a workpiece is carried into and out of a heat treatment furnace in a horizontal direction.

Conventionally, various surface modification heat treatment techniques using a metal material atmosphere have been known. (Patent Documents 1 to 4).
JP-A-56-23268 Japanese Patent Publication No. 51-20304 Japanese Examined Patent Publication No. 62-42993 JP-A-3-44457

  However, the conventional metal material surface modification heat treatment apparatus as described above has the following drawbacks.

  (1) A bell-type furnace in which the sealing performance is given priority over the structural and operational aspects of the furnace for the safety of the human body. And vertical arrangements such as pit furnaces, etc., resulting in poor operation efficiency and productivity and high processing costs.

  (2) When installing a bell-type furnace, a pit furnace or the like, in most cases, a space is required in the vertical direction, and in order to make the work transfer level uniform, a process such as forming a recess in the floor is necessary. Therefore, the installation of the furnace is very troublesome and inconvenient for operating workers.

  The present invention eliminates the above-mentioned drawbacks.

The metal material surface modification heat treatment apparatus according to the present invention includes a heat treatment furnace having openings for conveying workpieces on both sides, an open / close door that opens and closes each of the openings, and a work piece carried into and out of the heat treatment furnace. A means for transporting a workpiece that can be reciprocated in a horizontal direction, arranged outside the heat treatment furnace, adjacent to each opening, a fixed table arranged in the heat treatment furnace, and a means for introducing atmospheric gas into the heat treatment furnace; And a stirring fan disposed in the heat treatment furnace, wherein the open / close door includes an outer surface side case, an inner surface side case facing the opening of the heat treatment furnace, and a thermal insulator filled in the case. The inner case is provided with an arc-shaped portion that expands to follow the deformation of the heat treatment furnace due to temperature change on the outer periphery thereof, and the heat treatment furnace expands and contracts due to temperature change. When this inner surface side case of the door is telescopic in response to a double-walled walls are spaced apart from each other above and below the heat treatment furnace, connected by a can follow expansion in deformation between them due to a temperature change It is characterized by being.

The stirring fan is driven from the outside of the heat treatment furnace through a shaft rotatably supported by the wall of the heat treatment furnace through a magnetic seal .

The magnetic seal is made of a magnetic fluid.

  Since the metal material surface modification heat treatment apparatus according to the present invention has the above-described configuration, it is not necessary to arrange a transfer means for carrying in and out the work 5 in the heat treatment furnace 3, and the heat treatment generated in the furnace is not necessary. Inconvenient by-products such as poor transport due to accumulation of chlorides and the like never occur.

  Further, the upper wall 25a supporting the open / close doors 2a, 2b, the stirring fan 9 and the like can cope with expansion and contraction due to temperature change of the heat treatment furnace main body by the expansion function, thereby preventing any leakage problem.

  In addition, since the work can be transported and unloaded in the horizontal direction with respect to the heat treatment furnace, there are various benefits such as reduction in the height of the apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIG. 1, a muffle type corrosion-resistant, heat-resistant alloy heat treatment furnace (retort) 3 having openings 1a, 1b and doors 2a, 2b on both sides is used. On the side of the opening 1a and the other opening 1b, retrievers 4a and 4b that are reciprocally movable in the horizontal direction are arranged outside the heat treatment furnace 3, and are movably arranged on a table (not shown), for example, stainless steel. The steel work 5 is inserted by opening the opening / closing door 2a onto the fixed table 6 arranged in the heat treatment furnace 3 by the retriever 4a on the opening 1a side, and after the retriever 4a is pulled back, the opening / closing door 2a is closed, The workpiece 5 is hermetically stored in the heat treatment furnace 3, and the inside of the heat treatment furnace 3 is heated to, for example, about 300 ° C. to 800 ° C. by the heater 7 as shown in FIG. Injection tube (not shown) via by corrosive gases or solid raw materials such as HCl within, or NH ₄ Cl or the like is injected or placed on a workpiece, the heating temperature Yutakago is also a predetermined amount of the reformed gas and ammonia gas inlet For example, the workpiece 5 is subjected to surface modification heat treatment for 1 to 4 hours, for example, but it is performed for 2 or 3 days in the long-time treatment.

After soft nitriding, the opening / closing door 2b on the opening 1b side of the heat treatment furnace 3 is opened, the workpiece 5 is pulled out by the retriever 4b on the opening 1b side, cooled in the cooling chamber 8, and the cooling chamber 8 is purged with N ₂ gas. The finish of the surface of the workpiece 5 is made good.

  A stirring fan 9 is disposed in the heat treatment furnace 3 and is driven from outside the heat treatment furnace 3 through a shaft 11 rotatably supported by the upper wall of the heat treatment furnace 3 via a magnetic seal 10, for example.

  As shown in FIG. 2, the opening / closing door 2a or 2b includes an outer surface side case 12, an inner surface side case 13 facing the opening 1a of the heat treatment furnace 3, and a thermal insulator 14 filled in the cases 12, 13. The inner side case 13 is provided with an arc-shaped portion 15 which becomes an expansion following the deformation of the heat treatment furnace 3 due to temperature change on the outer periphery thereof, and when the heat treatment furnace 3 expands and contracts due to temperature change, Accordingly, the inner case 13 of the open / close doors 2a and 2b can be extended and retracted.

  As shown in FIGS. 4 and 5, the retriever 4a or 4b includes a traction bar 16, a guide roller 17 and a drive chain 18 for reciprocating the traction bar 16 in the horizontal direction, and a drive motor 19 for the chain 18. The head 20 has a head 20 provided at one end of the traction bar 16 so that the head can be raised and lowered from the upper surface of the traction bar 16 and a driving means (not shown) of the head 20. The head 20 can come into contact with the side surface of the work 5 if it is raised from the upper surface of the work 16, and if the traction bar 16 is moved horizontally in this state, the work 5 is moved and moved into the heat treatment furnace 3. It is carried or can be carried out from the heat treatment furnace 3.

  Further, as shown in FIG. 6, the magnetic seal 10 is adjacent to a plurality of permanent magnets 21 fixedly arranged on the outer periphery of the shaft 11 of the agitating fan 9 so as to be spaced apart from each other in the axial direction so that equal pole surfaces face each other. A pole piece 22 inserted and fixed between the permanent magnets 21; a recess 23 formed on the end face of the pole piece 22 on the shaft 11 side; And the magnetic fluid 24 containing the squeezed magnetic particles, and the magnetic fluid 24 has a sealing effect.

  In another embodiment of the present invention, a sintered automobile part is used as the work 5, the heat treatment furnace 3 is heated to 560 ° ± 5 ° C., and then steam is introduced, the work 5 is homo-treated for 60 minutes, and then the steam is obtained. The inflow is stopped, dehumidification is measured, a predetermined amount of metamorphic gas or ammonia gas is introduced, and the workpiece 5 is soft nitrided for 45 to 60 minutes, for example.

After soft nitriding, the opening / closing door 2b on the opening 1b side of the heat treatment furnace 3 is opened, the workpiece 5 is pulled out by the retriever 4b on the opening 1b side, cooled in the cooling chamber 8, and the cooling chamber 8 is purged with N ₂ gas. The finish of the surface of the workpiece 5 is made good.

  In still another embodiment of the present invention, a Ni alloy or stainless steel product is used as the workpiece 5, and after contact with the atmosphere of the halogen element in the heat treatment furnace 3, the atmosphere is modified gas or hydrocarbon gas and ammonia. Soft nitriding instead of gas.

  The subsequent processing is the same as in the above embodiment.

Incidentally, the heat treatment furnace 3 of the furnace wall is a double wall 25a was allowed apart from each other vertically as shown in FIG. 2, is formed by 25b, and expansion portion 26 for the flexible absorbing the heat treatment furnace due to the temperature change between the two interposed The shaft 11 of the stirring fan 9 and other gas introduction pipes (not shown) are supported by the upper wall 25a.

  In this way, it is possible to prevent an accident such as deformation of the heat treatment furnace due to temperature change and breakage of the shaft and other seals of the stirring fan due to contact with the atmosphere in the furnace.

It is a side view for description of the surface modification heat treatment apparatus of the metal material of the present invention. It is a vertical side view of the heat processing furnace in the surface modification heat processing apparatus of the metal material of this invention. It is a vertical front view of the heat processing furnace in the surface modification heat processing apparatus of the metal material of this invention. It is a side view for description of the retriever in the surface modification heat treatment apparatus for metal material of the present invention. It is a side view of the principal part of the retriever in the surface modification heat processing apparatus of the metal material of this invention. It is explanatory drawing of the magnetic seal | sticker in the surface modification heat processing apparatus of the metal material of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Opening 1b Opening 2a Opening / closing door 2b Opening / closing door 3 Heat treatment furnace 4a Retriever 4b Retriever 5 Work 6 Fixed table 7 Heater 8 Cooling chamber 9 Stirring fan 10 Magnetic seal 11 Shaft 12 Outer case 13 Inner case 14 Thermal insulator 15 Arc part 16 traction bar 17 guide roller 18 drive chain 19 drive motor 20 head 21 permanent magnet 22 pole piece 23 dent 24 magnetic fluid 25a double wall 25b double wall 26 expansion part for expansion and contraction absorption

Claims (3)

A heat treatment furnace having workpiece transfer openings on both sides;
An open / close door that opens and closes each opening;
A means for transferring a workpiece that is reciprocally movable in the horizontal direction and is arranged outside the heat treatment furnace adjacent to each opening to carry the work in and out of the heat treatment furnace.
A fixed table disposed in the heat treatment furnace,
Means for introducing atmospheric gas into the heat treatment furnace;
A stirring fan arranged in the heat treatment furnace,
Consists of
The open / close door is composed of an outer case, an inner case facing the opening of the heat treatment furnace, and a thermal insulator filled in the case, and the inner case has a temperature change at its outer periphery. An arc-shaped part that is an expansion following the deformation of the heat treatment furnace is provided.When the heat treatment furnace expands and contracts due to temperature change, the inner side case of the open / close door can be expanded and contracted accordingly.
A surface reforming heat treatment apparatus for a metal material, characterized in that the walls of the heat treatment furnace are double walls spaced apart from each other in the vertical direction , and the two are connected by an expansion capable of following deformation due to temperature change.   2. The surface modification heat treatment of a metal material according to claim 1, wherein the stirring fan is driven from the outside of the heat treatment furnace through a shaft rotatably supported by the wall of the heat treatment furnace through a magnetic seal. apparatus.   3. The metal material surface modification heat treatment apparatus according to claim 2, wherein the magnetic seal is made of a magnetic fluid.

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