Safe temperature for carbon steel

[Varoon]

What temperature will be considered to be safe for carbon steel for continuous heating application ? If it is heated continuously/intermittently to 300 degrees centigrade, is there any metallurgical deterioration ?

 

[metengr]

No, there is no measureable degradation at 300 deg C.

 

[Varoon]

Will the above comments be the same if temperature is 500 degrees centigrade ? Will there be any discolouration (blackening) ?

 

[metengr]

Will the above comments be the same if temperature is 500 degrees centigrade ? Will there be any discolouration (blackening) ?

No. Carbon steel at 500 deg C will exhibit creep deformation under load and will oxidize in air.