Interference fit quench plug assembly and methods for use thereof

Patent metadata

Field	Value
Publication number	US-10174395-B2
Application number	US-201514884005-A
Country	US
Kind code	B2
Filing date	Oct 15, 2015
Priority date	Oct 15, 2015
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A method is provided including heating a workpiece beyond a transformation temperature. The workpiece has at least one internal surface that has a nominal diameter, and a transformation diameter that corresponds to the start of a transformation from a first state to a second state. The method includes inserting a quench plug assembly into the the workpiece. The quench plug assembly includes at least one contact surface. The at least one contact surface has a diameter that is larger than the nominal diameter and at least as large as the transformation diameter. The method includes quenching the workpiece with the quench plug assembly disposed in the bore of the workpiece. The at least one internal surface is contacted and restrained by the at least one contact surface while the workpiece transforms from the first state to the second state. Also, the method includes removing the quench plug assembly from the workpiece.

First claim

What is claimed is:

1. A method comprising:
heating a workpiece beyond a transformation temperature, the workpiece having a bore therethrough and at least one internal surface, the at least one internal surface having a nominal diameter and a transformation diameter, the transformation diameter corresponding to a start of a transformation from a first state to a second state;
inserting a quench plug assembly into the bore of the workpiece, the quench plug assembly including at least one contact surface configured to contact and restrain the at least one internal surface of the workpiece during cooling of the workpiece, the at least one contact surface having a diameter at room temperature that is larger than the nominal diameter and at least as large as the transformation diameter, wherein the at least one contact surface provides an interference fit with the at least one internal surface at room temperature, wherein the at least one internal surface comprises a carburized surface, and the at least one contact surface comprises a carburized component contact surface, wherein the at least one internal surface comprises at least one non-carburized surface and the at least one contact surface comprises at least one non-carburized component contact surface, wherein a first fit between the carburized surface and the carburized component contact surface has a larger interference than a second fit between the at least one non-carburized surface and the at least one non-carburized component contact surface;
quenching the workpiece with the quench plug assembly disposed in the bore of the workpiece, wherein the at least one internal surface is contacted and restrained by the at least one contact surface while the workpiece transforms from the first state to the second state; and
removing the quench plug assembly from the workpiece.

2. The method of claim 1 , wherein the at least one internal surface comprises gear teeth.

3. The method of claim 1 , wherein the at least one contact surface comprises slots.

4. The method of claim 3 , wherein the slots comprise angled slots configured to contact gear teeth.

5. The method of claim 4 , wherein the slots further comprise slots configured to contact a smooth surface.

6. The method of claim 1 , wherein the quench plug assembly comprises a first portion and a second portion, and wherein inserting the quench plug assembly comprises inserting the first portion into a first end of the workpiece and inserting the second portion into a second end of the workpiece, the second end of the workpiece opposed to the first end of the workpiece.

7. The method of claim 6 , wherein inserting the quench plug assembly comprises an extension of one of the first and second portions fitting into an opening of the other of the first and second portions.

8. The method of claim 1 , wherein removing the quench plug assembly comprises removing the quench plug assembly with a press.

9. The method of claim 1 , wherein the at least one contact surface comprises a tapered surface, the tapered surface tapered along a length of the quench plug assembly.

10. The method of claim 1 , wherein the first state is an austenitic state and the second state is a martensitic state.

11. The method of claim 1 , wherein removing the quench plug assembly comprises removing at least a portion of the quench plug assembly with at least one bar inserted into an opening of the quench plug assembly.

Assignees

• Boeing Co

Inventors

• De Hennis Timothy M
• Ciccone Marco P

Classifications

• C21D9/32 Primary

  for gear wheels, worm wheels, or the like · CPC title

• C21D2211/008

  Martensite · CPC title

• C21D1/62

  Quenching devices · CPC title

• C21D2211/001

  Austenite · CPC title

• C21D6/00

  Heat treatment of ferrous alloys · CPC title