Carbon Steel, Impact Test

[mhuvalve]

Colleagues,
CS materials like ASTM A106-B, ASTM A105, A234 WPB, A672 CC60/70, ASTM A516 Gr 60/70 or ASTM A216 WCB, based ASME B31.3, Table A-1, have a lower temperature limit -29 deg C, the requirement of impact test for application under -29 deg C will be based on para 323.2.2.
Do you have experience in using the above materials on operating temperature below 0 deg C (Some of you may have minus ambient temperature) or near to the temperature limit without impact testing. Did you find the possibility of ductile-brittel transition on temperatures above?

Regards,

 

[metengr]

mhuvalve;
The above SA materials can be safely used down to -20 deg F (-29 deg C) without the need for impact testing "unless" specific code rules require impact testing because of component thickness limitations or heat treatment practice. The above materials produced and certified to SA specifications have by past expierence exhibited at least 15 ft-lbs of impact energy at -20 deg F (-29 deg C).

Did you find the possibility of ductile-brittel transition on temperatures above?

The only possibility would be for SA 216 WCB, where another Code of Construction (ASME Section VIII, Div 1, Part UCS) limits this material to 18 deg F (-8 deg C) and above with no impact test required.

 

[vesselfab]

does b31 have tables and curves where thinner sections of the same material is allowed to go colder than -20F without additional impact testing?

 

[eliebl]

B31.3 has Figure 323.2.2A. It has been a while since I have used but I believe it is similar, if not identical to the table in Part UCS of the vessel code.

EJL

 

[metengr]

vesselfab;
B31.1 , NO
B31.3, there is a table and figure similar to UCS-66 that state for service temperatures below -20 deg F (-29 deg C) in Table A-1 of Figure 323.2.2 a, the material could be used provided it is impact tested, and thickness limits are provided.