I would recommend testing if your not sure, it's cheap insurance and simple mechanical tests are not too expensive.
Unless you know specifically the temperature and time the steel was exposed, you really are not sure.
I have seen beams that were "straight" after fire damage that did not comply with the original specification requirements. The beams were supported in a manner that did not divulge deformation to the eye. We cut samples of material in locations chosen by the RDP for that project. I believe his locations were based upon a fire investigators report. Steel in the areas not considered "damaged" (but were still exposed to fire), the material was right were it should have been metallurgically speaking.
Coupons were cut at web or flange of the beams and a few columns. These were sent to a local construction lab for the usual tensile/yield, toughness and hardness. I remember one beam which had 2 coupons removed had one that was satisfactory, the other failed as it had failed the Charpy impact. Both coupons were removed from the center of the web. It was supposed to be our "control" unit as a comparison.
The specific test results were random. Some were satisfactory, some were not. The metallurgical engineer made recommendations to R&R some of these members.
It's cheap insurance.