1095 is a simple steel....basicly 99% iron and 1% carbon. It forges easily, takes a very sharp edge, is tough, and is cheap. The HT is well established. With the proper HT procedures (especially normalizing) it quenches well and gets quite hard. It does require a fast oil....or a water quench for the brave.
I call it a "Paint By Numbers" steel. The procedural format is all laid out for you - just do each step as proscribed ,and it will yield a known result.
As far as tempering temps go, (assuming a proper quench with full hardening) there is little drop in hardness until 500F. Assuming an as quenched hardness of HRC65, the hardness should be about HRC 61-62 with a 450F temper. I usually do 1095 at 425F. At 600F you will still get HRC 55-57
The ASM "Heat Treaters Guide" gives this info:
Procedures -
FORGE
NORMALIZE
ANNEAL
ROUGH MACHINE (grind)
SEMIFINISH MACHINE (shape bevels,drill holes,sand smooth,etc.)
AUSTENITIZE
QUENCH
TEMPER
forge at 2100F
normalize at 1570F
anneal at 1475F and cool at 50F/Hr
austenitize at 1475F
quench in oil (fast oil for knife blade thickness)
temper between 400F and 600F (for knife purposes)
1095 responds well to austempering ( referred to as ausquenching by some), with the quench being done in 600F salt and held at that temp for 2 hours. It forms Bainite (instead of Martensite) this way. (Tough and hard)
Stacy