Loading jig for wire coil and heat treatment method for wire coil using same

Abstract

The present invention relates to a loading jig (1) for a wire coil and a heat treatment method using the same, the loading jig comprising: a first mounting plate (2) on which a lower wire coil (W1) is mounted; a second mounting plate (3) which is positioned above the first mounting plate and on which the upper wire coil (W2) is mounted; a first pillar (4) that is interposed between the mounting plates and that supports the second mounting plate; a first cover (8) that closes the upper end of the lower wire coil; a second cover (9) that closes the upper end of the upper wire coil; a first gas flow path (11) that penetrates the first mounting plate in the plate thickness direction and guides an upward gas flow from below the first mounting plate to an inner diameter hole (W1a) of the lower wire coil; and a second gas flow path (13) configured so as to include a flow path (26) formed in the axial direction inside the first pillar and to guide a gas flow to an inner diameter hole (W2a) of the upper wire coil.

Description

technical field [0001] The present invention relates to a loading jig for a wire coil used when heat-treating longitudinally stacked wire coils, and a heat treatment method for a wire coil using the loading jig. Background technique [0002] In the heat treatment of the wire coil wound in a coil shape, heating or cooling gas flows along the outer periphery of the coil, and very little gas flows in the gap between the wires forming the wire coil. Therefore, the temperature difference between the surface layer portion of the wire coil that is in contact with the gas and the inside that is not in contact with the gas increases, and quality problems such as a decrease in the spheroidization rate and an increase in the decarburization amount tend to occur. [0003] In order to reduce the temperature difference between the inside and outside of the wire coil, it is conceivable to slow down the heating / cooling rate or prolong the soaking time. In this case, prolonging the processin...

AI Technical Summary

Problems solved by technology

Therefore, the temperature difference between the surface layer portion of the wire coil that is in contact with the gas and the inside that is not in contact with the gas increases, and quality problems such as a decrease in the spheroidization rate and an increase in the amount of decarburization are likely to occur.

[0003] In order to reduce the temperature difference between the inside and outside of the wire coil, it is also conceivable to slow down the heating / cooling rate, or to extend the soaking time. In this case, the extension of the processing time and the increase of the running cost become problems.

In addition, when the cooling rate during atmospheric cooling is slow, scales that are difficult to pickle are likely to be formed, resulting in a decrease in pickling performance.

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