Yes the frame is a matte finished stainless steel and the cylinder is a black finished stainless steel.
taurususa.com/index.php/revolvers/small-frame-revolvers/taurus-605/taurus-r-defender-605-357-mag-38-spl-p-matte-stainless-steel-3-00-in-vz-grips

Yes.

It is equipped with a steel alloy frame and cylinder, a stainless steel barrel, soft rubber grip, fixed front and rear sights, a transfer bar and the Taurus Security System as safety features, as well as a hammer firing system.

Hi Charles, yes sir, the frame, cylinder, and barrel are all stainless steel.
The barrel & frame have a Matte Stainless finish and the cylinder has a Matte Black finish.
Stay safe & have a great day!

Hi Charles and welcome. Yes Sir, frame and cylinder are both steel. Cheers, stay safe and enjoy!