Heat input for each pass or for each layer ( ASME IX)? 5

[abdomen]

When heat input is required is it mandatory to perform the measures for each pass ? or is it sufficient to do the measures for each layer .( according to ASME IX)

thank you

 

[SectionIX]

Hi Abdomen,


From my perspective, continous monitoring is required when supplemental essential variables apply to insure compliance to Code.

 

[jwhit]

I just went through a Superduplex qualification to ASME IX and stood in the welders booth for every pass, timing them and recording amps and volts as well as maximum interpass temperature. Anything that goes on the PQR is supposed to reflect exactly what happened in welding the test plate/joint.
Jeff

 

[Kiwi2671]

Abdomen,
Each layer may be made up of 1, 2, 3, 4 or more beads and the amps, volts and travel speed should remain constant for all.
If there is a change for some reason in amps, volts or travel speed for an individual bead (within a layer)then that should be recorded, otherwise record per layer.

Of course a layer may consist of a weave or multiple beads which will have a large difference in heat input so this must be clearly shown on the WPS/PQR.

pass: a single progression of a welding or surfacing operation
along a joint, weld deposit, or substrate. The result of
a pass is a weld bead or layer.

layer: a stratum of weld metal consisting of one or more
beads. See figures QW/QB-492.1 and QW/QB-492.2.

Cheers,
Kiwi

 

[Guest102023]

Per bead, not layer.

 

[Fizza453]

I would agree with kiwi.
Heat input shall be determined for each pass and each layer. No of passes may or may not be equal to no of layers. PQR is the record what happend during the welding of test coupon, so each pass heat should be determined.

Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[Kiwi2671]

Brimstoner,
Heat input is a result of amps/ volts / travel speed so if you put 4 beads (eg. a heavy wall pipe) in one layer and no parameters were changed why would you have to measure every bead ?
Regards,
Kiwi

 

[Fizza453]

Heat is calculated for every bead in order to check if heat input is the same or not for each bead in the same layer, if it is the same for each bead, then for that layer this heat input shall be written on the PQR.



Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[Guest102023]

Kiwi2671,

My practice is to record all parameters for all beads on a PQR. You can't be sure that heat input is actually 'constant' until you've subsequently done the math. How fussy you want to be about it is up to you and your inspector, and how critical the procedure is.

When I know that a steel has a large margin of safety (in terms of exceeding impact requirements) I will ask for high heat input in the qualification test. Then not only can I sleep better, but monitoring becomes simpler, because in practice welders will always work comfortably within the limits of the WPS parameters.

 

[Leonardobetta]

During Welding Procedure Qualification;measuring heat input is a mandatory record for generating & validating required measurements that let your PWPS qualification succeed with subject parameters. Furthermore, subject records will be your margin reference during welding operations; as the afformentioned is a contractual obligation (i.e welding specification per project requirements) with your Contractor/Client or TPI's for approving your inhouse procedures.

On the other hand, during welding production; stringency of heat input measurement frequency requirement varies among metallurgy type CS/LTCS/SS/SDSS/Titanium/CUNI for the purpose of avoiding expected defects related to the previously mentioned.