I believe the TRS frizzens are alloy 6150, a medium carbon-chromium alloy that, as Dan said, does not spark well, if at all. I had to sole mine with 1084, using electrical solder that melts at around 375 F. Since that is the tempering temperature I was looking for, I was able to harden the sole at around 1550 F using a water quench, temper it back to 375 F, then solder it to the frizzen face without loosing any temper.
Bill