Determine the grade of ductile iron

[BraveFellow]

I have a steel tube with a ductile iron ring insert that is brazed in place with copper. Internal threads are cut into the ductile iron ring. I know the chemical composition of the ductile iron, but do not have enough of the material to perform a mechanical test of the material. The microstructure of the ductile iron is bainitic which I think indicates it is austempered (correct me if I'm wrong).

The chemical composition is low in Nickel, Iron, Mo, etc. So this leads me to believe this material is Grade 1 austempered ductile iron per ASTM A897. The iron insert is machined from bar stock.

Does anyone see a problem with this logic? THANKS!

 

[metengr]

There is no Grade 1 per the ASTM A 897 material specification I have reviewed. There are strength Grades identified by tensile/yield/elongation. If it were me, I would try and obtain a Brinell hardness just to confirm Grade because typical Brinell hardness is listed for each strength Grade.

 

[TVP]

I concur with metengr. Should be ADI, you just need to confirm which grade according to ASTM A897.