Cold Temperature effect on welding 1

[PEinVA]

Does a cold temperature have an effect on the weld strength/capacity?
We have some welding going on in temperatures in the 20s and low 30s,and possibly tomorrow in the 10s.

I'm looking on AISC and AWS as we speak, but I thought I'd ask the seemingly endless knowledge base here.

Thanks in advance!

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[metengr]

Does a cold temperature have an effect on the weld strength/capacity?

Yes it does. Cold weather means....faster cooling rates and surface moisture formation... which means... increased susceptibility to cracking during and after welding..... which means reduced load carrying capacity.

So preheat the steel in the region to be welded with a torch to at least 50 deg F before welding.

 

[0707]

"3 - How to do it well: Welding in cold Weather

Q: What is the coldest ambient temperature allowed for welding carbon steel and stainless steel pipes and structure?

A: Whenever ambient temperature causes water vapor condensation upon metals, it is recommended good practice to preheat before welding up to 120 C to make sure the joints are dry.

A few authorities, specifying the conditions for welding of Bridges and similar Structures, put the coldest ambient temperature limit, below which welding is not allowed, at 0 0F or -18 0C.
See:

http://www.thruway.state.ny.us/business/design-manual/appendixf.pdf

(page 12) and

http://www.dot.state.oh.us/testlab/StructuralSteel/Field-Welding-Inspection-Guide.pdf

(page 9)


Other authorities, dealing with welding requirements for Piping and Pressure Vessels, put the coldest ambient temperature limit, below which welding is not allowed, at 32 0F or 0 0C.
See:

http://www.wbdg.org/ccb/NASA/NASAASC/NS15055.pdf

(page 6)


For ASME Codes and Standards, the minimum temperature for welding is generally specified at 50 0F or 10 0C.

Minimum temperature and preheat requirements for welding on pressure retaining items are also referenced in the National Board Inspection Code (2004 Edition), Appendix B."

extract from

http://www.welding-advisers.com/PRACTICAL_WELDING_LETTER-PracticalWeldingLetterNo30.html

luis marques

 

[MotorVib]

Both 0707 & metengr hit it. You are not that cold people do welding like this all the time in that kind of weather. My company is working a project in Canada right now and it just take longer just everything when the temp drop.

Chris

"In this house, we obey the laws of thermodynamics." Homer Simpson

 

[dbooker630]

In automotive we use 70F minimum for structural welding to avoid the possibility of hydrogen introduction.

 

[dvd]

Find out if you need pre-heat. A pre-heat calculator might help. The paper below might help some too.

http://www.jflf.org/pdfs/papers/keyconcepts1.pdf

https://ssl.lincolnelectric.com/foundation/item.asp?prodnum=WC-8&PID=17

 

[unclesyd]

What little we have welded in the 40-50F range we always require preheat and that the finished weld be covered with an insulating blanket. Also any weld over 12" in cold weather we normally require a brother in-law process or a good setup for maintaining preheat.

All cold weather welding is tented if at all possible.