ASTM A455 fracture toughness value

[936616]

When we evaluated a air tank integrity, we need A455 fracture toughness value.But now we can't get it by experiments.
the thickness of tank shell is .375''(9.5mm). It was desgined by asme bpvc code viii, div.i and charpy test is not requirement by ug-120(d).
Anyone would like to help me to provide fracture toughness of A455.
TANKS

LAYCASHCN

 

[metengr]

Are you asking for KI_c or CVN impact energy values? Also, what service temperature?

 

[936616]

Yes, CVN impact energy values is welcome,and based it, we can estimate KIc . The design min. temperature is -20F(-29 C degree).
Thank you for response and helps.

 

[metengr]

One approach is to use 15 ft-lbs for your condition assessment, and estimate a KI_c value. This is the most conservative approach because 15 ft-lbs is the minimum specified value by Code for this service temperature.

Option 2 is to use API/ASME FFS-1 (API 579) Part 3 - Assessment of Existing Equipment for Brittle Fracture.

 

[936616]

Thank you and we have use the option 2 to do this work. And we adopt curve B materials and set Reference temperature as -20F. Then we caculate KIc according to the API code and with working temperature as -20F. But the results is not good. So if possible, we hope to have some real CVN impact energy values for this hot-rolled-plate of Vessel.
The other way is prove the real working temperature is not lower than -13 C degree( in fact, the tank is located in room and the outside enviroment temprature(out-room)is not lower thant -10 C degree for the whole year),than everything will be OK.
But some experts said we should evaluated at design min. working tem. I know it will be conservative, but the results is not good.

that is the reason why we hope to have real values of A455 Plate .

Thanks , your comments and help really is great value to us.

 

[metengr]

936616;
What exactly are you trying to accomplish? Rerating or fitness for service?