Can anyone help identify this material?

[cmwalker545]

I am having a hard time finding a match for this material. The attached picture is etched in 5% Nital at 100X. I also attached a picture of XRF results.
I have a theory that this is a form of ductile iron that has maybe gone through a heat treatment process but I am unsure.
Any help or advice is much appreciated.
Thanks,

 

[cmwalker545]

Not sure if I can attach more than one image in a thread. This attachment is the 100X 5% Nital image.

 

[mrfailure]

Your image does not look like a 100X etched photomicrograph, and it is really unusable. Was this a replica?

You need to first do the work properly before you ask: Examine it in the as-polished condition at to confirm whether you have ductile iron, THEN etch and examine at 100X and 500X for microstructure. If you can remove physical samples, then make a proper mount to evaluate and have quantitative chemistry done. XRF will not tell you about the carbon to identify cast iron but quantitative analyses will.

 

[cmwalker545]

Not a replica, the image is 120X not 100X, sorry.
I am comparing some OEM castings vs. Chinese aftermarket. This attached picture is of an OEM casting at 120X.
The nodules seem much smaller than the OEM version.

 

XRF is even more useless for cast iron than it is for carbon steel.
Get a proper chemical analysis and better metallography.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[mrfailure]

I second Ironic's comments, and want to add that you need to first examine and photograph at 100X in the as-polished condition, then compare with cast iron classifications shown in ASTM A247. Then etch to confirm the amount of pearlite. Chemistry is usually not called out for ductile iron but I like to take Si and C from the quantitative evaluation and compare with general graphs to show they are in the expected range for ductile iron.

 

[dbooker630]

It could be a DQ&T ductile iron but from the photomicrograph it's difficult to resolve the matrix as to whether it is pearlite or martensite.

 

[arunmrao]

It is having low nodule count and the shape of the nodules is also not round. Matrix I cannot say if it is martensitic or pearlitic. But I see in the Chinese sample a mottled structure perhaps. Though not very clear.Some sharp carbide needles or is it a polishing defect .

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.