×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Heat Input Calculation for Multiple Electrode SAW

Heat Input Calculation for Multiple Electrode SAW

Heat Input Calculation for Multiple Electrode SAW

(OP)
How does one calculate the Heat Input for SAW when Multiple Electrodes are used.

For Example
3 electrodes are used to weld a joint.
All the 3 has different Voltage and Current Parametere.

Should we calculate the Heat Input for all the 3 separately and add it up.
Or should we check whether they are connected in series or parallel and then calculate?

If the Job has Impact test, is it necessary that heat Input in individual electrode is restricted to Max heat input (Sex IX) or is it the net Heat Input that should be accounted for?

RE: Heat Input Calculation for Multiple Electrode SAW

bmoorthy;
How was the original WPS for submerged arc welding (SAW) qualified for impact testing - using a max electrode size or all three sizes?

In accordance with Section IX, QW-409.1, if the original WPS was qualified for a max heat input per pass under Supplementary Essential Welding variable listed under QW-254 for the SAW process, any increase in heat input above this maximum heat input per pass requires re-qualification.

QW-409.1 lists two methods where heat input would be increased per pass - using the standard heat input formula or by increasing the volume of deposited weld metal per unit length of weld.

From what you have stated, if your original WPS was not qualified with 3 different electrode sizes to account for the max range of heat input OR you decided to add two additional electrode sizes to increase the volume of weld deposited, you need to re-qualify the SAW WPS.

An increase in heat input by either using a larger electrode size or by increasing the volume of weld deposited per pass will adversely affect the toughness of the base metal and this is the reason for this supplementary essential welding variable for SAW.

RE: Heat Input Calculation for Multiple Electrode SAW

Adding further to metengr's comments, assuming the wires are spaced closely together, < 3" or so, you would add the three together and divide by travel speed.  Eg. If you had 550 A, 32 V on the first, 450 A 30 V on the second and 400 A 30 V on the third, and your travel was 31 ipm, your heat input would be calculated as [(550*32*60)+(450*30*60)+(400*30*60)] / 31 = 83,419  j/in.  For impact tested applications, in your terms, net heat input would be critical.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources