Low Temperature Sevice

Date 12-07-2010 16:38

Your welding electrode mfg's data sheets should say something about if that wire was tested at low temp or not and give some values about what temp it was tested at. If the data sheets do not show a temp low enough for the intended service call them up directly and ask. Sometimes the data sheets may not have the lower temp shown, but they may have tested and met the requirement for the low temp service........ they may have additional data on that electrode to send you to satisfy your customer's question. Keep in mind the sheilding gas has an effect on the outcome of those tests, so if you call them specify what blend of gas you are using.

By RonG

Date 12-07-2010 16:48

Define Low Temperature? -60F? We have procedures useing E7018M qualified to -60F.

The trick is to do just that---Qualify the procedure. Ask the customer if he wants to foot the bill to find out.

By swnorris (****)

Date 12-07-2010 17:58

PA,

Your mention of low service temperature brings to mind demand critical welds in a structure that's designed to resist seismic forces. When this occurs, welds have to be made with a filler metal capable of providing a minimum Charpy V-Notch (CVN) toughness of 20 ft-lb at -20 degrees as determined by the appropriate AWS classification test method or the manufacturer certification, and 40 ft-lb at 70 degrees as determined by the seismic code or another approved method... when the steel frame is normally enclosed and maintained at a temperature of 50 degrees or higher. The lowest anticipated service temperature (LAST) of most buildings is typically 50 degrees, but for structures with service temperatures lower than 50 degrees, the qualification temperature per seismic criteria must be 20 degrees above the lowest anticipated service temperature, or at a lower temperature. GMAW solid wire is exempt from production lot testing when the CVN toughness of the electrode equals or exceeds 20 ft-lb at a temperature not exceeding -20 degrees as determined by AWS classification test methods.
The manufacturer’s certificate of compliance should suffice as evidence of meeting this requirement. Also, structural drawings and specifications are required to indicate the lowest anticipated service temperature of the steel structure, if the structure is not enclosed and maintained at a temperature of 50 degrees.

By js55

Date 12-07-2010 20:20

I'm sorta on the same page with Ron. There really is no such thing as low temp, other than when your nipples get stiff, but you can't quantify that under an AWS or ASME requirement. The advice contained herein is excellent. Find out what temp they are talking about. If your wire can go to -20 (and my nipples are definately stiff at -20, though I don't generally go about exposing them, or anything else for that matter, at -20) and you need -50, then no your wire cannot be used.

By Arctic 510 (**)

Date 12-15-2010 21:00

It's -45° here in sunny Alaska today.

You wouldn't want to expose much at all right now.

:-)