Does anyone know about  corrosion problems of inconel alloys in CO/CO2 bearing gas (probable formation of nickel-tetra carbonyl)at temperature below 200°C.

That should be a slow ground ball for Inconel 600. It is designed for much worse environments.

I know that Ni is extracted by a water gas containing C0 which at a temperature of about 50°C forms Ni(CO)4 , this complex  at temperature above 250°C decompose again to Ni + 4CO. It possible that the same gas in contact with a nickel alloy at the above mentioned temperature extract selectively the nickel? I haven't found any reference about this  in corrosion literature, but i think this is a normal process of nickel production.

"The leaching of Ni from Ni-containing alloys by CO(g) does not appear in the general corrosion literature because these alloys normally have a protective oxide surface.  It is more of a laboratory & very specialized industry process."

Probably all commercial alloys of common metals [not gold] come from the mill with an oxide film.  The carbonyl formation can only happen if you clean the metal and expose it to CO(g) without heating in air, or if you reduced the surface oxide at some higher temperature and then cooled  in a strongly reducing atmosphere.
I have removed surface oxides from both iron and cobalt samples by the latter method. Used a silica glass tube inside a tube furnace, with plug valve and inlet valve at one end and a stopcock at the other, burning off high-purity H2 as it exited. After cooling, I closed the valves and transferred the whole thing to a glovebox containing high purity 'gettered' argon.  In such a manner, one can perform reactions normally prevented by the passive oxide film.
 
The thin amorphous oxide that forms on an alloy at low/room temperature normally differs in composition from the high temperature, crystalline oxide. The metal ratio of the low temperature oxide is much closer to that of the alloy, whereas the composition of the high temperature oxide is primarily determined by the thermodynamic stabilities of the component oxides and the activities of the metals in the alloy. This is why it is necessary to passivate SS, to increase the Cr/Fe ratio of the low temperature amorphous oxide.  Whereas, the oxide that forms at higher temperature is naturally Cr2O3-rich.

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