Dear Sanjay

It is impossible to say anything about the chemical composition. You must do EDX to recognize the composition.

Yes I agree with that indicated by Armin Rajabi  but if I based on the morphology of the attached SEM image of Iron based material sample tested for wear at 500 degree celcius as presented by sanjay .

There is an film and can be characterize as stable and below or not  reaches the critical thickness at which it becomes unstable and breaks up to form wear debris because of brittleness and internal stress of film . The sliding direction is clear and little grooves and scratches with no loosed debris are observed. The surface is not smooth and uniformly covered with continuous layer of patches ( 80-100μm) which can be visually seen. If so and due to high temperature, only oxide wear has taken place.

Thanks