BEAD HEIGHT PROBLEM

[vks1986]

Dear All,


we manufacturing double side(internal and external) saw tandam arc(three) of pipe as per api 5l.
pipe length is 12.300meter
automatic saw welding..

external and internal saw start from f-end and stop at t-end in pipe.

problem is starting of welding up to 1meter bead height coming 3.5mm and bead shape is narrow as compare to below..

where end of welding up to 1meter bead height coming 2.6mm and bead shape is wider
in same parameters at both end..
above problem accured only in external weding..

we are using auto. saw in which stick out controlled automatically..
constant current power source.

 

[metengr]

You may need to adjust/check your travel speed during start-up or use run-on tabs.

 

[metengr]

Also, check the roundness/alignment at each end of the formed plate, and compare with the mid-length of the pipe.

 

[stanweld]

You electrical parameters and grounding location may also need changing.

 

[Rich2001]

Throwing out a few ideas

1. Check the grounds. Use a IR thermometer and monitor the temperature of the ground. As needed take the ground connectors apart and clean and add a lubricate with a silver-based conductive lubricant. Many companies fail at this this simple practice that has a huge affect on high current SAW processes.

2. What ramp rates are programmed in the controller? You might need to adjust the soft-start parameters.

3. Are you using run-on and run-off tabs?

Richard