Table UG-84.6 Required HAZ Impact Test Specimen Set Removal 5

[RAGER]

Dear all ,

Table UG-84.6 Required HAZ Impact Test Specimen Set Removal

when Base Metal Thickness t ≤ 3/ 4 in. One set of HAZ Specimen in the Locations of Their Approximate Centerline 1/ 4 t to 1/ 2 t.

We got a laboratory test report following
1.Base Metal Thickness:4mm (SA-516 70)
2.v-notch Specimen for HAZ: 3.3 X 10 X 55 mm

question:
1. Is 3.3 MM acceptable for a 4t thin plate?
2. should we ask laboratory to re-make a HAZ v-notch Specimen at 1 X 10 X 55 mm ?

 

[r6155]

1) YES
2) NO

Regards

 

[RAGER]

Dear r6155

I am looking forward to know why 3.3 mm is acceptable for HAZ Specimen ?

 

[r6155]

See UG-84 (C) (3)

Regards

 

[CWEng]

1) Yes
2) If you thought the 3.3mm specimen was in question, wouldn't the 1mm specimen make it worse? Besides, there is no standard specimen at 1mm anyway, that's too thin. 2.5mm (.099") is the smallest specimen recognized by ASME Section VIII. Anything below that thickness is exempt from impact testing.

 

[EdStainless]

If you can take a 3.3mm sample where the centerline falls in the 1/4 - 1/2 t range, then why not?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[RAGER]

Dear all,

This is our AI comment:

Due to it is a subsize specimen, you don't know the real HAZ where it located is.

Even you do a 2.5mm (.099")specimen, it can not represent the HAZ zone.

He ask to confirm HAZ area by "etched" before test.

 

[r6155]

Please, can you tell us the MDMT?

Regards

 

[weldstan]

Your AI's statement is nonsense. This has been done thousands of times in the past on ASME VIII vessels. Because the subsize specimen is greater than 80% of the maximum possible thickness no temp reduction is required. Advise calling your AIA's technical rep to disabuse the AI's objection. The HAZ can be clearly discerned in such thin wall wels.

 

[david339933]

Etching is a requirement of UG-84 for the HAZ.

 

[RAGER]

Dear ALL

Sorry for late reply.

r6155 :the MDMT is -40°C

david339933 : Yes ,Etching is a requirement of UG-84 for the HAZ. We ask another laboratory to perform "etched" on subsize specimen befor test it.