Pqr Assistance 625 overlay and 309/316

[robietherobot]

I am pretty rusty when it comes to writing a PQR and new to sub sea and i need some help

we are trying to qualify a few procedures on overlay and some questions have arose in refrence to the following questions.

When doing hardness surveys are the surveys averaged in a specific manner or does each survey have to be a make or break for the PQR example

12 surveys were performed and the average was 248 on 625 to 4130 on an overlay.But we had a couple of readings in that survey that showed 290 PWHT was performed at 1190 for 16hrs Nace MRO 0175 reads like a riddle to me.

The other question i have is when performing a 309/316 overlay with the same PWHT cycle the surveys on the stainless will read lower(197) than the 4130 but the client says the requirements are 200-250 unless i can average the results how can this be achieved

If you average all of the results the test we have performed so far we ar ok to proceed but if you dont I have to figure out something else any help would be greatly appreciated

 

[metengr]

Hardness results are not averaged, they are reported as individual readings based on a traverse across the weld region. The hardness of the 309/316 stainless steel filler metal will be lower than the 4130 or 4130 base metal HAZ. The filler metal readings are not part of the 200-250 hardness requirement by your client.

Work with a Welding Engineer, you can't learn this stuff on the internet.

 

[robietherobot]

thanks

 

[SJones]

16 hours of PWHT might not do the 309/316 or 625 a lot of good in terms of corrosion performance, but I guess that the client hasn't voiced that as an issue!

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[robietherobot]

We have to do that due to code restrictions some of the items we weld on are 20 an not many but there are some 40 to 50 in thick after reviewing for several hrs i have for the the acceptance criteria is as follows

197-235 for 4130 in base as well as HAZ so i am looking into the base material due to the readings being all over the place not much consistency at all
The welding was very consistent also had our client witness them we were very careful on the heat input