TIG Welding Heat Affected Zone

[Mechotron]

I have a query regarding heat affected zone due to TIG welding. A 1.38" OD tube with a wall of 0.085" wall is TIG welded. There is a wire of 16AWG with the insulator running under the wall. I am trying to find out if the Heat from TIG welding will have a consequence on wire being snapped. Is there a method to find the heat affected zone due to TIG Welding.

mechotron

 

[metengr]

Mechotron;
Can you please show the configuration above with a sketch or better describe it? I am having a difficult time envisioning this set-up. What does under the wall mean? Is this a vertical tube and a separate wire runs parallel with the tube at some separation distance from the tube OD surface?

 

[Mechotron]

Hi Metengr

I have attached a rough schematic of the set up. If you have any queries, please let me know.

 

[metengr]

Mechotron;
Based on your sketch, it would appear that you are going to use a partial penetration butt weld to join the tube. If this is the case, the wire should be at a safe enough distance away from the partial penetration weld where the heat input from the GTAW weld deposit will not result in excessive exposure to heat. If this is a full penetration weld, this would probably damage the wire in the annulus of the tube/sleeve.

I would use a relatively low interpass temperature (less than 250 deg F) when making this butt weld to avoid excessive heat exposure to the wire.

 

[pipewelder1999]

The likelyhood of melting through the wall and burning the wire is going to be related to the parameters you weld with. A mechanized method in which travel speed is controlled by a machine would provide repeatable results.

If it is done by hand, it shouldnt be a problem if the welder understands the desire to achieve partial penetration and uses amperage settings, travel speeds, etc that would minimize the likelhood of melting through.

If this is an insulated wire, you may have a hard time with insulation damage unless it is heat resistant.

Gerald Austin
Iuka, Mississippi

http://www.weldingdata.com