Selection of pipe scedule & materials

Wow!Sounds like main steam heading to the turbine. I suggest you solicit the services of a qualified application engineer for this process. This is not a guess and stab application IMO, as this is some serious pressure/temps, and many items will need to be factored besides the materials, i.e controlled expansion, guides/anchors, etc.

If we tell you can you afford to take the risk? parameters are Steam turbine and 100NB shows it is a medium sized one.

<...what pipe schedule and pipe materials can be used to withstand 100 bar steam pressure with 510 deg C Temperature for 100 NB pipe size...>

Answer: the ones the qualified piping designer has specified, with second person checks and approval on the piping design in accordance with the employing company's practices and procedures!

With that temperature and pressure you are looking at a chrome alloy pipe most likly, 1-1/4 chrome or 2-1/4 chrome in the A-335 series.

At that pressure and temperature it will be in ASME 2500# class flange rating.

To find the schedule you will need to calculate it using the relevant piping desing code, ASME B31.1, ASME B31.3, ISO, etc., apply corrosion allowance and mill tolerance to arrive at a calculated wall thickness and then pick the next thickest standardly available pipe schedule.

If you go with a stainless steel material you will get that down to an ASME 1500# flange class pipe system.

http://www.engineeringtoolbox.com/astm-steel-pipes-pressure-temperature-d_742.html

here u can calculate by converting units of pressure from kpa to kg/cm2