heat input restriction 1

[sajid8768]

Dear friends
please say the range of heat input in LTCS (a333 gr6)welding and which std reference for this?

 

[weldstan]

There is not a range; only the maximum heat input used during procedure qualification. With proper choice of welding filler metals (composition) and welding processes, I have readily met -50F and lower with heat inputs up to 70 KJ/in.

 

[Duwe6]

weldstan, what/how did you get 70KJ/inch at -50°F ?? Could you get it with a 'field' process like SMAW or GTAW? Any and all info will be greatly appreciated, sir.

[i suspect there will be an SA-333 project in my near future]

 

[weldstan]

With GTAW and SAW.

I have often met up to -60F impact requirements with SMAW at 55+ KJ/in. In one instance in England, the original PQR referenced a heat input < 20 KJ/in. Both the client and I knew that the welders would never adhere to the requirement and as a result we witnessed qualification of a production weld made in the 5G position, recording and calculating a heat input of 53 KJ/in. It passed easily meeting absorbed value at -60 F using an E8018-C3 electrode and a GTAW root pass with 1% Ni bare wire filler metal. We then had them requalify a number of other similar "too low to be believed" heat input procedures to address the remainder of the work under B31.3.

We have typically qualified our low temperature (-50 F) carbon steel procedures using between 45 KJ/in and 55 KJ/inch, which is more typical of the actual heat inputs expected in the field when using 5/32" diameter electrodes.

I have been directing qualification of low temp (-50F) procedures since 1974.

 

[Duwe6]

Good info weldstan, and a star for you, sir. With thanks.

And it is refreshing to see somebody recognize that ridiculously low heat inputs [<20KJ/inch] cannot be produced in the field with manual welding.