ASTM A572 Gr. 50 Grain Structure
ASTM A572 Gr. 50 Grain Structure
(OP)
I have a yoke, please see attached sketch, which is bent from a 3" x 1-1/4" bar of ASTM A572 Gr. 50 Steel. If I switch from the a bent bar to a burn out, do I loose any strength due to a change in the grain structure?





RE: ASTM A572 Gr. 50 Grain Structure
RE: ASTM A572 Gr. 50 Grain Structure
RE: ASTM A572 Gr. 50 Grain Structure
How much difference in tensile strength is there between going with the grain and going across the grain (or maybe no definite grain direction at all)?
RE: ASTM A572 Gr. 50 Grain Structure
What is the application of this yolk? Is this for static load? Dynamic load conditions or both? Will this be used for lifting? These are important questions to answer because shapes made from burnouts are commonly used under limited service conditions.
RE: ASTM A572 Gr. 50 Grain Structure
RE: ASTM A572 Gr. 50 Grain Structure
How much difference in tensile (or ultimate) strength is there between going with the grain and going across the grain (or maybe no definite grain direction at all)?
RE: ASTM A572 Gr. 50 Grain Structure
RE: ASTM A572 Gr. 50 Grain Structure
A couple of comments related to this entire project;
1. Considering the strength level of this material, cold bending to form the bracket means you obviously reached the upper limit for formability. This material can be warm or hot formed into shape but this could effect bulk properties. This would also apply to heat generated from thermal cutting.
2. Why not increase the size of the bracket necessary to reduce the applied tensile stress and go with a lower strength material, A 36 shape, where heat will not effect bulk mechanical properties upon forming? This material is easier to work with in comparison to Grade 50.
RE: ASTM A572 Gr. 50 Grain Structure
Thermal cutting of steel certainly can change the grain structure. You could be reducing the strength of the material significantly. Considering that this is for overhead lifting of an enormous mass, you need to consult design/testing/safety standards applicable to this work. Good luck.
RE: ASTM A572 Gr. 50 Grain Structure
RE: ASTM A572 Gr. 50 Grain Structure
Since tensile properties of plate are only specified at minimum values with actual values above minimum, the through thickness tensile strength should still meet minimum requirements.
RE: ASTM A572 Gr. 50 Grain Structure
I have had some recent experience with failed grade 50 structural shapes which barely met the 50 Ksi min Y.S and 65 Ksi min UTS per the supporting MTR. Production tensile tests didn't meet the SMYS,and as an added plus, nil ductility at 80 F.
RE: ASTM A572 Gr. 50 Grain Structure
RE: ASTM A572 Gr. 50 Grain Structure
RE: ASTM A572 Gr. 50 Grain Structure
Not exactly industrial grade Haiku, but true nonetheless. Physicians have there "first do no harm", and we are also charged with life and death responsibility. Great products are not made by cutting corners. We're liable. My 2 cents.