Hi
I had a query regarding Mentioning of the Heat Input for
Impact applicable procedures, If a WPS is qualified using Multiple PQR's
which cover the range from 6 mm to 200 mm.
i.e PQR 1 : qualifies from 6 to 12mm
PQR 2 : qualifies from 10 to 20mm
PQR 3 qualifies from 16 to 200mm.
Now as per the practical experience from the PQR's the
maximum heat input for each procedure is different and goes on increasing as the thickness increases.
Do I need to mention (In the WPS ) the range for Current , Voltage and speed of welding seperately for each thickness range so that the corrresponding maximum heat input values are not exceeded.

SantoshC,

The variable to control is the Heat Input. The HI of the PQR weld may not be exceeded in production. For this reason, the welder shall receive sufficient guidance to weld with the limited heat input. Welding inspection, QC and AI must be able to verify the HI of the production weld.

If your PQRs are qualified with e.g. 10, 12, and 15 kJ/cm, and the WPS uses all three PQRs for qualification, the maximum permitted HI for the Wps is 10 kJ/cm.

From my experience the WPS shall indicate current, voltage and either travel speed or unit length. When I watch the welder welding, my first question to the QC inspector is: how do you assure that the heat input is not exceeded?
Usually there is a welding record indicating the actual A,V, and the speed or unit length. And then it is easy to calculate the actual HI.
When there are no such records, or there are no calibrated Ampere and voltmeters, or the travelspeed is not controled, it will be very difficult to accept the weld. right?
DK

PS this is not so critical, when the weld is exempt from impacts.