St52 heat resistance

You fail to tell us if this is tubing, bars or plates;

There are several varieties of this by Werkstoffe number. 1.0570, 1.0421, and 1.0580 come to mind, there are others that might be applicable as well.

One of these is microalloyed,and uses columbiuum,vanadium and titanium additions to respond to thermal treatment/ controlled cooling from rolling forging to develop mechanical properties. You do not indicate a temper or thermal condition (annealed) only hot rolled. Using normalized as a proxy for Hot rolled, and presuming no funky cooling practices, I would expect TS to range 490-630 mpa; 22 % elongation, and Yield to be 355 Mpa at room temperature in hot rolled as rolled product.

So those developed properties would be erased by increasing temperature in the application.

Best I can do with the data given.

milo

I think you mean the actual EN 10025 designation S355. Anyway, St52 is a general purpose structural carbon steel and I wouldn't use it above 300ºC. Maximum yield strength reported at 350ºC is about 50% of RT one (that is 175 MPa more or less). If you really have high temperatures it's advisable to use some other steel designed for such service such us those includes in DIN EN 10028-2