GMAW Heat Inupt

[jzmx]

We have GMAW machined welding equipment with pulsed amperage power sources, wire feeder, travelling system and ADM (arc data monitor). The PQR and WPS were qualified with heat input calculated per QW-409.1 (a) Voltage x Amperage /Travel Speed where A was actually average amperage based on 25k samples per second at the power source output. The instanteneous heat input can be calculated and displayed during the welding. There are sensors for voltage, amperage, wire feed speed and travel speed. The welding is at 1G position.

The ASME IX edition since 2010, requires an external power or energy meter for the waveform controlled machine, including plused GMAW, per new QW-409.1 (c) energy / weld bead length or power x arc time / weld bead length.

Does the existing GMAW welding equipment meet the new code requirements?

Regards
Jimmy

 

[WE91]

If the power source has the capability to produce instantaneous heat input readings, that allow for welding/inspection personnel to verify heat input is with in the original max allowed I do not see an issue. Section IX Non Mandatory Appendix H H-200 "When the welding equipment does not display instantaneous energy or power, an external meter with high frequency sampling capable of displaying instantaneous energy is typically used." (This would allow for use of the machine read out or an external meter.) H-400 allows WPSs qualified per QW-409.1(a) as long you determine heat input ranges in accordance with method QW-409.1(c) (Amend/ clarify on the procedure what settings/travel speeds will insure compliance to max qualified heat input.)

Also I would note that heat input is not always an essential variable depending multiple factors.

All above references are from Section IX 2021, at a quick glance 2023 appears to make the same statements.

 

[SJones]

Is the question: does the PQR meet ASME IX requirements for pulsed welding? There is no requirement to have an external meter. Calculation method (a) is not to be used for waveform controlled welding.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[jzmx]

The PQR was qualifed before 2010, with impact testing as required by ASME III. The welding power source is plused current for PQR welding and productin welding. It should be waveform controlled. But the calculation formula is V x A / Travel Speed for the code before 2010, but A was and is actually average value.
There is Arc Data Monitoring system that cat as an external meters with data of voltage, avarge aperage, wire feed speed, and travel speed.  

 

[WE91]

Does the system calculate the heat input instantaneously? My interpretation of section IX "Non Mandatory Appendix H," is that you can utilize the data from the original PQR as long as you can confirm that your heat input is in compliance using method (c) for production welding. As far as the original amperage being the average that is very common, when welding with constant voltage setups( wave form control isnt necessarily cc or cv,)the machine fluctuates the amperage in an attempt to maintain voltage, and vice versa for constant current. Being the PQRs were qualified prior to 2010 and section IX does not give a degree of accuracy tolerance on PQR sample readings I would look to the end user to determine if 25k samples per second is adequate and if so I would make sure the WPS are written in a way that the welder/inspection personnel are able to insure compliance to heat input restrictions. When in doubt run a new PQR to insure compliance.

Just my 2 cents.

 

[jzmx]

Rick0001, thank for your input. I am pretty sute that the production welding is in accordance wit the late code, but different formulas for calculations with same results. I need some independent opinions.