ASTM A1011 CS Type B Impact Resistance

[mrfailure]

Can I expect this steel to have good Charpy impact resistance down at sub-zero temperatures (say, -40 deg. F)? If so, why? I have been told A1011 was developed for Arctic applications, but I have not found any published references in my search . I do notice that impact testing is not among the requirements or supplemental requirements for A1011, unlike ASTM A36 (which is listed as an alternate material but data suggests poor impact resistance at low service temperatures).

 

[metengr]

What do you consider good? >15 ft-lbs at -40 deg F? Are you sure about the ASTM designation Type B versus the other A1011 Grades? ASTM A1011 CS
Type B is a standard specification for hot-rolled, steel sheet and strip and coils of carbon steel, structural steel, high-strength low-alloy steel, high-strength low-alloy steel with improved formability, and ultra-high strength steel. The thickness for the above is 0.239" or less by specification, which would favor lower CVN values at lower temperatures.

 

[mrfailure]

metengr,

[ul]
[li]I'm sure about the designations: The customer specifies either A1011 CS Type B or A36. The application needs impact resistance at -40 deg. F to prevent service fractures (I cannot go into details on why).[/li]
[li]For Charpys, I consider good to be test fracture that is >50% shear. I'm not sure what the associated impact energy is, but that can be established through testing provided I meet the % ductility requirement.[/li]
[li]Finally, you raised a question I never even considered: the component is 0.35" thick, meaning A1011 does not apply.[/li]
[/ul]

Any thoughts on structural steel plate or shapes that has good impact resistance at -40 deg. F and good formability (portions need to be bent 90 deg.)?

 

[metengr]

Look at bridge steels A588, A572 etc.

 

[mrfailure]

Of course! Thanks!

 

[weldstan]

Don't expect high absorbed energy values at -40 without demanding impact testing to be done at -40 in your purchase order. A-36 can be purchased with impact testing to meet -40 requirements; however, without specifying same, one can expect transition temperatures up to and above 70F
In one instance we experienced brittle failure of A-572 at approximately 32F. Charpy testing in the subsequent failure analysis provided 4 - 5 ft-lbs absorbed energy at 32F adjacent to the fracture location. At the center of the web over 50 ft-lbs were obtained at 32 F,

 

[mrfailure]

Totally agree Stan. That recommendation was made to my customer as being essential if they continue to specify A36.