IP Library › Granted Patent US 7,431,193
Granted Patent B2
US 7,431,193 · App. 11/208,294 · Granted Oct 7, 2008

Vibration stress relief of weldments

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,431,193
App. No.
11/208,294
Granted
Oct 7, 2008
Kind
B2
Abstract

A method of stress relief for stainless steel combustion turbine components includes vibrating the components during welding at a subharmonic frequency. The proper frequency is selected to be below a harmonic frequency, and to produce an amplitude in the range of ¼ to ½ the amplitude produced by a harmonic frequency. The component to be repaired is vibrated during and after welding at this frequency.

Claims (15)

1. A method of reducing stresses within a stainless steel combustion turbine component during welding, the method comprising:

identifying a harmonic frequency of the combustion turbine component;

selecting a frequency that produces an amplitude of about ¼ to ½ an amplitude produced by the harmonic frequency, and which is a lower frequency than the harmonic frequency; and

vibrating the combustion turbine component with a constant force at the selected frequency while welding the combustion turbine component, wherein the constant force has a ratio to combustion turbine component weight of about 5:2.

2. The method according to claim 1 , further comprising vibrating the combustion turbine component at the selected frequency as the combustion turbine component cools after welding.

3. The method according to claim 1 , wherein the frequency selected is between about 35 Hz and about 150 Hz.

4. The method according to claim 1 , wherein the combustion turbine component is made from a stainless steel from the group consisting of 403 stainless steel and 410 stainless steel.

5. The method according to claim 4 , further comprising vibrating the combustion turbine component at the selected frequency as the combustion turbine component cools after welding.

6. A method of reducing stresses within a stainless steel combustion turbine component during welding, the method comprising:

identifying a harmonic frequency of the combustion turbine component;

selecting a frequency that produces an amplitude of about ¼ to ½ an amplitude produced by the harmonic frequency, and which is a lower frequency than the harmonic frequency; and

vibrating the combustion turbine component with a constant force at the selected frequency while welding the combustion turbine component over substantially an entire welding cycle,

wherein the combustion turbine component is made from a stainless steel from the group consisting of: 403 stainless steel and 410 stainless steel,

further comprising vibrating the combustion turbine component with a force having a ratio to combustion turbine component weight of about 5:2.

7. The method according to claim 6 , wherein the frequency selected is between about 35 Hz and about 150 Hz.