JP3208839B2 - Heat treatment method of material to be treated - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heat treating a material to be treated. 2. Description of the Related Art It is widely practiced to directly heat or cool a material to be processed in a processing chamber surrounded by a heat insulating material with hot or cold air. For example, there is a case in which a steel material is charged into a processing chamber surrounded by a heat insulating material, and the processing chamber is heated by circulating hot air heated by a heater with a circulation fan. Another example is a case in which a heated steel material in a processing chamber surrounded by a heat insulating material is cooled by circulating cool air cooled by a cooler in the processing chamber by a circulation fan. The present invention relates to an improvement in a heat treatment method for a material to be treated.

[0002]

2. Description of the Related Art Conventionally, as a heat treatment method for a material to be treated as described above, a heat treatment apparatus usually having one treatment chamber is used. In some cases, a material to be processed is continuously heated with hot air or cooled with cold air using a heat treatment apparatus having two or more processing chambers. In any case, the processing chamber is surrounded by a heat insulating material, and hot air or cold air passes from one side to the other side opposite to the material to be processed in the processing chamber in a relationship orthogonal to the loading / unloading direction. Then, the material to be processed is directly heated with hot air or cooled with cold air.

[0003] However, such a conventional method has a disadvantage that the heating or cooling rate of the material to be treated is not uniform. When heating the material to be treated with hot air, the heating speed of the material to be treated located at the central portion among the materials to be treated charged into the treatment chamber is relatively fast, but the heating speed of the material to be treated located at the end portion is relatively high. When the material to be treated is cooled by cold air, the cooling speed of the material located at the center among the materials charged into the processing chamber is relatively fast, but the material located at the end is relatively fast. The cooling rate of the material is relatively slow. The reason is that the material to be treated located at the center is easily affected by hot air or cold air as it is, so the heating or cooling rate is relatively fast, but the material to be treated at the end is close to the heat insulating material. The heat insulating material has a large heat capacity, and therefore has a lower heating or cooling rate than the material to be treated.
Further, at the time of cooling, the heat or cooling rate becomes relatively slow due to heat radiation from the heat insulating material to the material to be processed.

[0004]

The problem to be solved by the present invention is that in the conventional method, the heating or cooling rate of the material to be treated is not uniform.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a processing target material in a processing chamber surrounded by a heat insulating material. In the heat treatment method for the material to be processed, in which the material to be processed is directly heated or cooled with a cold air by passing the hot or cold air to the side, the heat capacity along the passing direction of the hot or cold air between the heat insulating material and the material to be processed. A heat treatment method for a material to be treated, characterized by disposing a heat transfer enhancer made of a metal plate having a small size and heating or cooling the material to be treated with hot air or cool air.

An important point in the present invention is that when the material to be treated in the processing chamber surrounded by the heat insulating material is directly heated or cooled by hot air or cold air, the hot air or cold air flows between the heat insulating material and the material to be processed. It is located where the heat transfer enhancer is arranged along the passing direction. As mentioned above, the processing chamber is surrounded by thermal insulation,
When the material to be processed in the processing chamber is heated with hot air or cooled with cold air, hot or cold air is passed from one side to the other side opposite to the material to be processed in a relationship orthogonal to the loading / unloading direction. Therefore, in the case of passing hot air or cold air from the right side to the left side in a relationship orthogonal to the loading / unloading direction with respect to the material to be processed, for example, the heat transfer promoting body has a relationship orthogonal to the loading / unloading direction of the material to be processed. The heat insulating material and the material to be processed are arranged along the front and rear heat insulating materials, respectively, between the heat insulating material and the material to be processed, and further along the upper heat insulating material in parallel with the loading / unloading direction of the material to be processed. And between them. Further, in the case where hot air or cold air is passed from the upper side to the lower side in a relationship orthogonal to the loading / unloading direction with respect to the material to be processed, the heat transfer promoting body has a relationship orthogonal to the loading / unloading direction of the material to be processed. The heat insulating material is disposed between the heat insulating material and the material to be processed along the front and rear sides, and further along the heat insulating material on the left and right sides in a relationship parallel to the loading / unloading direction of the material to be processed. It is arranged between each material.

[0007] The heat transfer accelerating body thus arranged can be mounted inside the heat insulating material surrounding the processing chamber at an interval from the heat insulating material, or mounted at the end of the tray on which the material to be processed is loaded. However, in the case where the material to be treated is continuously heated with hot air or cooled with cold air, it is preferable that the material is attached to the end of the tray in order to avoid a complicated structure of the processing chamber. As such a heat transfer enhancer, a relatively thin metal plate having a small heat capacity, for example, a stainless steel plate can be used.

[0008]

For example, in the case where hot air is passed directly from right to left in the processing chamber in a direction perpendicular to the loading / unloading direction of the material to be processed and the material to be processed is heated directly by hot air, the heat transfer promoting body is covered. When disposed between the heat insulating material and the material to be processed along the front and rear heat insulating materials which are perpendicular to the loading / unloading direction of the processing material, the heat transfer enhancer is immediately heated to the temperature of the hot air by the hot air. Then, since the heat is radiated from the heat transfer promoting body to the material to be processed at the end near the heat insulating material on the front and rear sides, the material to be processed at the end is also heated at substantially the same speed as the material to be processed at the center. When the material to be heated after cooling is cooled with cold air, the heat transfer enhancer is immediately cooled to the temperature of the cold air by the cool air, and the heat transfer enhancer is heated from the heated material close to the front and rear heat insulating materials. Since the heat is radiated, the material to be processed at the end is also cooled at substantially the same speed as the material to be processed at the center. According to the present invention, the heating or cooling rate of the material to be treated can be made substantially uniform.

[0009]

1 is a longitudinal sectional view schematically showing a state of the present invention in a short direction (a direction orthogonal to a loading / unloading direction). Inside the furnace shell 11, a processing chamber 13 surrounded by a heat insulating material 12 is formed. A roller 14 is laid inside the processing chamber 13 through the furnace shell 11 and the heat insulating material 12, and a tray 21 is placed on the roller 14. Is loaded. Processing chamber 13
Inside the heater 1 through the furnace shell 11 and the heat insulating material 12.
5, 16 and a circulation fan 17 are inserted, and a perforated flow straightening plate 18 is interposed between the heater 15 and the tray 21. A guide plate 19 is interposed between the fan 17 and the tray 21.

In one embodiment of FIG. 1, the heaters 15, 16
The hot air heated by the circulating fan 17 is circulated by the circulating fan 1.
7 → heater 15 → rectifying plate 18 → processed material A loaded on the tray 21 → heater 16 → circulation fan 17 Therefore, in the embodiment shown in FIG. 1, the hot air is passed from the right side to the left side of the processing target material A in the processing chamber 13 in a relationship orthogonal to the loading / unloading direction.

FIG. 2 is an enlarged longitudinal sectional view schematically showing the tray of FIG. 1 in a longitudinal direction (a direction parallel to the loading / unloading direction).
The convex portions of the first-stage spacers 41a and 41b, the upper portions of which are formed in the concave portions and the lower portions of which are formed in the convex portions, are fitted to the base 31, and the shelves 51 are fitted in the concave portions of the spacers 41a and 41b.
Are mounted, and the protruding portions of the second-stage spacers 42a and 42b similarly formed by penetrating the shelf 51 into the concave portions are fitted. Hereinafter, by repeating this, the convex portions of the similarly formed spacers 43a to 45a and 43b to 45b of the shelves 52 to 54 of the second to fourth stages and the third to fifth stages are sequentially mounted or fitted, The protrusions of the base frame 55 are fitted into the recesses of the fifth-stage spacers 45a and 45b. At the left and right ends (front and rear sides in FIG. 1) of the tray 21, heat transfer enhancers 61 and 62 made of a metal plate having a small heat capacity are mounted.
In FIG. 2, hooks 71, 72 attached to the lower portions of the heat transfer enhancers 61, 62 are fitted into the recesses of the base 31, and hooks 73, 74 attached to the upper portion are attached to the base frame 55. Are inserted in the through holes.

Therefore, in one embodiment of FIG. 1, as described above, hot air is passed from right to left in relation to the material A in the processing chamber 13 in a relationship orthogonal to the loading / unloading direction. Heat transfer enhancers 61 and 62 are arranged between the heat insulating material 12 and the material A to be processed along the front and rear heat insulating materials 12 which are orthogonal to the loading / unloading direction of the material A to be processed. When heating the processing target material A with the hot air, the heat transfer promoting members 61 and 62 are arranged along the direction in which the hot flow passes through the processing target material A.

A stainless steel plate having a thickness of 2 mm was attached to the tray shown in FIG. 2 as a heat transfer enhancer, and a cylindrical stainless steel material having an outer diameter of 32 × 35 mm was loaded in a total of five stages and loaded into a processing chamber. Then, according to the above-described embodiment of FIG. 1, hot air at 700 ° C. was passed. When the temperature of the cylindrical stainless steel material loaded at the center reaches 700 ° C., the temperature of the cylindrical stainless steel material loaded at the end is 695 ° C.
Met. On the other hand, when the stainless steel plate as the heat transfer enhancer was removed and heated with hot air in the same manner, the cylindrical stainless steel loaded at the end when the product temperature of the cylindrical stainless steel loaded at the center reached 700 ° C. The temperature of steel is 6
80 ° C.

[0014]

As is clear from the above, the present invention described above has an effect that the heating or cooling rate of the material to be treated can be made substantially uniform when heating or cooling the material with the hot air. is there.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a state of an embodiment of the present invention in a lateral direction.

FIG. 2 is an enlarged longitudinal sectional view schematically showing the tray of FIG. 1 in a longitudinal direction.

[Explanation of symbols]

11 ... furnace shell, 12 ... heat insulating material, 13 ... processing chamber, 14 ... roller, 15, 16 ... heater, 17
... circulation fan, 21 ... tray, 31 ... base, 41a-45a, 41b-45b ... spacer
51-54 ... shelf, 55 ... base frame, 61, 62 ...
・ Heat transfer enhancer

Continuation of the front page (56) References JP-A-62-131187 (JP, A) JP-A-3-253513 (JP, A) JP-A-57-85925 (JP, A) JP-A-4-13653 (JP) , U) JP-B-51-33842 (JP, B2) JP-B-51-13095 (JP, B2) JP-B-47-17607 (JP, B1) (58) Fields surveyed (Int. Cl. ⁷ , DB) Name) C21D 1/00 C21D 1/767 F27D 7/04 F27D 9/00

Claims (3)

(57) [Claims] An object to be processed in a processing chamber surrounded by a heat insulating material.
From one side in a relationship orthogonal to the loading / unloading direction.
Hot air or cold air is passed to the other side
Heat treatment of materials to be processed by heating or cooling the raw materials directly with hot air
In management method, that by placing a small metal plate of the heat transfer accelerating members of Yan have heat capacity to the passage direction of the hot air or cold air to a hot air or cold air cooled該被treatment material between the insulation and the material to be treated A method for heat-treating a material to be treated, characterized in that: 2. The method according to claim 1, wherein a heat transfer enhancer is provided inside the heat insulating material. 3. The method according to claim 1, wherein a heat transfer enhancer is attached to an end of the tray on which the material to be processed is loaded.