ASTM A1011 CS Type B Steel: Yield Strength & Properties

[Satonam]

I'm currently working on a design project which requires using sheet metal with ASTM A1011 CS Type B steels. Reading their latest designation for this type of steel, it is shown that the yield strength varies between 30 - 50 ksi. [1] Maybe it's just because I'm new and naive, but I find this variation very alarming considering that our current manufacturer can't provide the mechanical properties of the steels they use in our products. According to Alro Steel, suppliers of this type of sheet metal are only required to meet chemical standards but ensuring consistent physical properties aren't mandatory. [2] How is that allowed and how do engineers trust these materials when used in the automotive and aerospace industry? My impression is that controlling the chemical composition of the steel is much easier and more affordable than controlling its properties, is this assumption correct?

As a work around to this problem, I'm considering taking the lower extreme and assume all our steels are at 30 ksi. With that said, I would still be missing other mechanical properties, such as poisson's ratio, the elastic modulus, shear modulus, etc. -which I need in order to perform reliable simulations on Solidworks. I guess I can find the elastic modulus with an empirical test by relating the measured deflection of a beam, but at that point, it's probably cheaper if we sent it to a third party for testing (as suggested by Alro Steel).[1] https://compass-astm-org.libdb.njit.edu:8443/EDIT/html_annot.cgi?A1011+18a#s00022
[2] https://www.alro.com/divsteel/Metal...1/A1018 CS Type B&Mat=CARBON STEEL&Type=Plate

 

[jrmichler]

The 30 KSI yield sounds about right for a hot rolled very low carbon steel. It will increase with work hardening, such as by cold rolling. Increasing yield strength by cold working also reduces ductility. Cold rolled steel can be annealed to increase ductility, with the side effect of reducing yield strength to 30 KSI.

The SolidWorks default properties for hot rolled mild steel should work well enough.

As for elastic modulus, steel is steel. All steels have the same elastic modulus. Highly alloyed steels, such as stainless steel, have a slightly lower elastic modulus.