Hello, I have a question, do you remove the sample to do the surface removal ? What's the goal of the study and what's you worries exactly ?

Is "microstructure analysis" = grain size? Results might be skewed just a tiny bit for most steels, but more so for steels with high degree of work hardening (such as high manganese steels). For phase analysis I do not see any problems. I assume you are going to remove metal with polishing without applying an excessive force and with plenty of cooling agent.

Ayoub El Bendali Yes, I do. A part of surface will be removed with a depth of 0.1 mm until it reaches 1 mm. For every 0.1 mm, XRD testing will be carried out. The goal is phase analysis.

The goal is phase analysis.

I am worried about the change of carbon content on the steel surface during sample preparation.

Vladimir Dusevich, you are right. The aim is to analyse the phases of martensite, austenite and ferrite for medium carbon steel.

Would you be able to provide information on the type of polish suitable for this case. Is dimple grinding also suitable?

https://www.struers.com/en/Knowledge/Grinding-and-polishing#

I would avoid a dimple grinding, it will not give you a flat surface.

Vladimir Dusevich, the sample surface is the involute shape of the gear flank part. Is there a special equipment to remove the surface with a certain depth of cut?

Yes, there are several ways to improve the microstructure of a material without affecting its microstructure. These include heat treatment, cold working, and surface treatments such as shot peening and chemical etching. Heat treatment involves heating the material to a specific temperature and then cooling it at a controlled rate. Cold working involves applying pressure to the material to change its shape and properties. Surface treatments involve using abrasive materials or chemicals to alter the surface of the material. All of these methods can be used to improve the microstructure of a material without affecting its microstructure.

To ensure that the surface removal process has no effect on the test results, the following steps should be taken:

1. Use a high-precision grinding machine to ensure that the surface is removed in uniform increments.

2. Use a lubricant to reduce friction and heat during the grinding process.

3. Use a microscope to inspect the surface after each increment to ensure that the surface is free of any defects.

4. Use a high-quality abrasive material to ensure that the surface is not damaged during the grinding process.

5. Use a high-quality polishing material to ensure that the surface is smooth and free of any scratches.

6. Use a high-quality XRD machine to ensure that the test results are accurate and reliable.

Hello.

I guess there will be no problem and you detect the change in the material with the depth, especially that x ray have a penetration depth lower than what you remove each time. Great Luck, you may consider doing a heatmap or a waterfall plot to make a quality figure for the results. In addition, you may do a refinment in order to track the change of an element's content over depth.

Regards,

I would still say grinding and polishing and follow by chemical etching.

If you really want the surface to be unaffected, i would recommenf for you to go for grinding and polishing go as low as 0.1 micron polishing to get it to mirror surface then follow by Cross section polishing.