Preheat and Preheat Maintenance
Preheat and Preheat Maintenance
(OP)
Dear All,
I have one question. Our welder is carrying out a qualification of a new WPS, by welding a cast coupon in duplex 2205 with duplex 2209. The welding activities shall be distributed during 5 days.
To reduce to minimum the presence of humidity on the weld, the welder shall lightly pass the flame of a burner on the weld surface. This is going to happen each day, before starting welding activities.
Should this "drying" activity be considered formally as preheating and (= should the temperature of the weld joing be registered on the WR?)
Thank you for your help
MC
I have one question. Our welder is carrying out a qualification of a new WPS, by welding a cast coupon in duplex 2205 with duplex 2209. The welding activities shall be distributed during 5 days.
To reduce to minimum the presence of humidity on the weld, the welder shall lightly pass the flame of a burner on the weld surface. This is going to happen each day, before starting welding activities.
Should this "drying" activity be considered formally as preheating and (= should the temperature of the weld joing be registered on the WR?)
Thank you for your help
MC





RE: Preheat and Preheat Maintenance
RE: Preheat and Preheat Maintenance
this is exactly what I supposed.
MC
RE: Preheat and Preheat Maintenance
Petrotrim Services
www.petrotrim.com
RE: Preheat and Preheat Maintenance
RE: Preheat and Preheat Maintenance
RE: Preheat and Preheat Maintenance
sounds clear to me.
I will note the minimum temperature on the PQR; isn't it mandatory to list the same minimum temperature on the supported WPS?
Jbeckhou,
I don't have a min/max value. The aim of the operation is just to eliminate moisture on the weld just before starting the welding activities at the beginning of the day; therefore, I expect the preheat temperature to be around 30-35°C.
I do have limitation on interpass temperature (150°C max), but that's another matter... :)
MC
RE: Preheat and Preheat Maintenance
Best regards - Al
RE: Preheat and Preheat Maintenance
When I write a PQR, the 'Preheat' on it is the lowest starting temperature. Likewise, the 'Interpass' is the highest interpass temperature used.
RE: Preheat and Preheat Maintenance
The interpass temperature is the temperature of the test piece once welding has begun. Usually the interpass temperature is measured adjacent to the location where the next weld bead will be initiated, just before initiating the arc.
Best regards - Al
RE: Preheat and Preheat Maintenance
your help has been much appreciated! :)