I have done XRD of the corrosion product of steel tubing which failed in a gas condensate well having 7 mole % Carbon dioxide and 50 ppm Hydrogen sulfide but I am not getting any significant peaks. The result also has a lot of noise. I have done xrd on different XRD instruments and scanning time upto 3 hours. The best result I have got is attached with some noise reduction. Is this result acceptable?
It depends on how you collected the surface corrosion products . Did you get only corrosion products or you got a big amount of the metal specimen itself into the fine powder that you used to run XRD? How did you collect the corrosion products?
Can you identify any corrosion product on the best XRD scan you got?
The inner surface of the tubing was severely corroded. It required a little effort to remove corrosion product with a sharp pointed steel tool.
You can look at the result image attached . I am not sure if some small peaks (red circled) represent the product or noise.
Hi Masood,
I would check the intensities of those different scans and if significant then may smooth the spectra and run it against the software database to see if any of the peak matches.
XRD for non homogeneous powder will have a lot of noise because the crystal structure is destroyed. Most propably you got a lot of the pure metal itself in the sample or you have complex corrosion reaction that generate mixed phases . If you can reduce the noise manually or intensify the picks and run the scan against the database that would give an idea about the corrosion reaction.
By the way: washing the powder with isopropyl alcohol or xylene an drying it over night at 45C.
Or even washing it with water and then drying it immidiatly in hot nitogen before you wash it with xylene or IPA will remove a lot of salts and hydrocarbons and will enhance the XRD scan
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