Weld Heat Affected Zone definition

[jodipedro]

On what parameters is a Heat Affected Zone defined, compliant to the ASME Codes??

Is it on the thikness like t/4 + weld width?
Is it on the weld width itself, like weld width + 1/4 of it??

Thanks to everyone!

 

[weldtek]

Per the ASM dictionary, HAZ is ' the portion of the base metal that was not melted during.. welding, but whose microstructure and mechanical properties were altered by the heat'. So the HAZ width depends on a lot of factors, which would include heat input, base material type and thickness, etc.
Expect in most cases that the HAZ is going to be very narrow, probably less than 1/8"

 

[PEHasan]

Now the question comes, to avoid HAZ (heat affected zone), how much minimum distance should be kept between the two
welds?

As part of good engineering practice, we usually keep a gap of: -

Maximum of "5 times the thickness of thicker member" and "50 mm" between the two welds.

 

[SJones]

I'm not sure that ASME has any specific requirements for HAZ dimensions.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[metengr]

ASME does not gave any specific requirements on this subject. There have been previous postings regarding spacing between adjacent weld toes in piping. European standards might have more information on this subject.