Quenching method

Patent metadata

Field	Value
Publication number	US-12378620-B2
Application number	US-202017420581-A
Country	US
Kind code	B2
Filing date	Mar 16, 2020
Priority date	Mar 29, 2019
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

Provided is a method for executing a quenching method in which an object to be treated that is a quenching target is cooled with a quenching coolant that is a coolant for quenching, in which the object to be treated is moved inside the quenching coolant accumulated in a cooling tank, by a moving device for moving the object to be treated, and at least from when the object to be treated comes into contact with the quenching coolant until a surface of the object to be treated undergoes martensitic transformation, a state in which a relative speed of the object to be treated and the quenching coolant is slower than a moving speed of the object to be treated is maintained.

First claim

The invention claimed is:

1. A quenching method in which an object to be treated that is a quenching target is cooled with a quenching coolant that is a coolant for quenching, wherein
the object to be treated is moved inside the quenching coolant accumulated in a cooling tank, by a moving device for moving the object to be treated, and
at least from when the object to be treated comes into contact with the quenching coolant until a surface of the object to be treated undergoes martensitic transformation, a speed of the moving device is controlled to synchronize with a predetermined flow speed of the quench coolant.

2. The quenching method according to claim 1 , wherein auxiliary cooling is performed by applying an auxiliary coolant on the object to be treated, in which the auxiliary coolant is a coolant for auxiliary cooling discharged from a plurality of nozzles, and after the auxiliary cooling of the object to be treated is stopped before the surface of the object to be treated reaches a martensitic transformation start temperature, the object to be treated is cooled to a temperature equal to or lower than the martensitic transformation start temperature by the quenching coolant.

3. The quenching method according to claim 2 , wherein the auxiliary coolant and the quenching coolant are a coolant containing water as a main component or a quenching oil.

4. The quenching method according to claim 2 , wherein the auxiliary coolant and the quenching coolant are either both coolants containing water as a main component or both quenching oils.

5. The quenching method according to claim 1 , wherein the object to be treated is pre-cooled by a gaseous pre-coolant before the object to be treated is cooled by the quenching coolant.

6. The quenching method according to claim 1 , wherein the moving device includes a support base on which the object to be treated is placed and a support portion that supports the base, and
the speed of the moving device is controlled by controlling a motor connected to the support portion, which controls the raising and lowering speed of the support base.

7. The quenching method according to claim 1 , wherein the speed of the moving device is controlled to match a control target amount of direction and the predetermined flow speed of the quench coolant.

8. The quenching method according to claim 1 , further comprising determining a state in which the surface of the object to be treated has undergone martensitic transformation based on whether a predetermined period has elapsed after the object comes into contact with the quenching coolant.

9. The quenching method according to claim 8 , wherein the predetermined period is determined based on an predetermined distortion amount of the object.

10. The quenching method according to claim 8 , wherein the predetermined period is determined based on a time at which a martensitic fraction of a surface of the object is 28% or more.

11. The quenching method according to claim 8 , wherein the speed of the moving device is set to zero when the predetermined period has elapsed.

12. The quenching method according to claim 8 , wherein the quenching coolant comprises water or an aqueous solution with water as a primary component.

Assignees

• Aisin Corp

Inventors

• Obayashi Koji
• Kasai Daisuke
• Matsuzaka Keisuke
• Naito Takeshi
• Ryujin Takeshi
• Matsumura Toshiaki

Classifications

• C21D2211/008

  Martensite · CPC title

• C21D1/64 Primary

  with circulating liquids · CPC title

• C21D1/60

  Aqueous agents · CPC title

• C21D1/58

  Oils · CPC title

• Y02P10/25

  Process efficiency · CPC title