A572-gr50 Angle Fracturing

[SJMoore]

I work for a fab shop where we have successfully rolled 5" x 3 1/2" x 3/8" angle with the 5" leg in for a good customer for many, many years. Years ago of course it was all A-36. Now it's all coming in with multiple certifications and the expected higher yields and tensiles. On two out of our last three orders the angles are fracturing just below the heel on the 3 1/2" leg. I haven't yet come up with any other common factor than this mateial change that might contribute to this. The material has even come from different mills. To my simple little mind it seems that if you raise both the yield and tensile, you surely have an effect on the ductility. Am I barking up the wrong tree?

Thanks,
Scotty

 

[metengr]

Yes. You may simply have exceeded the bend radius for forming with the higher strength material. You should have one or more of the bent angle failures evaluated by a met lab to establish a definite root cause for the cracking.

 

[SJMoore]

Sorry, I failed to mention this is being rolled to a 28' radius. I keep a history book and we've rolled this same size as small as a 4'-6" radius in the past. That seems like a huge difference in the material's ability to withstand the stress.

The supplier is coming Monday, and they're trying to line up a metallurgist to come at the same time. I'm just trying to get better educated myself before they come.

Thanks for the reply.

Scotty