Heat affected zone removal by grinding

[warrior1987]

Hi everybody, I have a question. Thank you for your time.

We need to remove a complete weld on a shell that belongs to a pressure vessel. The removal will be performed by grinding.

We will remove both the weld metal and the heat-affected zone (HAZ).

Here’s the question: the HAZ on austenitic stainless steels is typically around 4 to 5 mm at most. However, some coworkers have told me that we need to remove one thickness from both sides of the weld. The plate thickness is 16 mm.

Do you know of any recommendations or standards about the width of the HAZ that needs to be removed? what are you experienced?

In my opinion, removing 16 mm from both sides of the weld seems excessive.

Again, thank you very much for your time.

 

[goutam_freelance]

As per Sec IX QW-202.3 "WPS qualified for groove and fillet welds shall be applicable to weld repairs to groove and fillet welds-----"

So qualified weld procedures can be used for repair welds also.

For additional safety, a repair weld sample(with the required removal of HAZ) can be further qualified by testing.


Engineers, think what we have done to the environment !

https://www.linkedin.com/in/goutam-das-59743b30/

 

[DekDee]

Unless your "co-workers" are Welding Engineers probably better to ignore their advice.
You need to submit a TQ to your Client detailing what you intend to do (including size of HAZ removal) and get their approval.

 

[warrior1987]

Thank you for your anwers.

I was thinking that one approach could be to perform non-destructive metallography to determine the approximate width of the HAZ.

 

[goutam_freelance]

One way to do this will be to take two plates of the same PV material and size, prepare and do welding as per WPS, take sections and do metallography examination.

NDT for this is unknown to me.

Engineers, think what we have done to the environment !

https://www.linkedin.com/in/goutam-das-59743b30/