Hello. I have a small propane forge, and so far I've been working only with 1084, doing all of my HT using magnet and waiting for about a minute after non-magnetic before quenching. I've gotten pretty good results, but I want to become more scientific about it. So I bought a piece of black iron pipe and a thermal probe to be able to control the temperature better.
Most of the sources I looked at say that I have to bring the steel to about 1500 and soak it for some time (this is where they start differing, suggesting times between 2 and 10 minutes). My understanding is that if the temperature remains around 1500, the actual time of soak is not that important because the carbon just stays in the solution. My question is - what exactly constitutes soaking time? Is it a time from the moment I put steel into the forge or time from the moment it reached austentizing temperature? If it's the latter, how long does it usually take for a room-temperature piece of steel of standard knife proportions (1 inch tall, 1/8 thick, 3-4 inches long) to go up to 1500 when surrounded by 1500 temperature in the pipe?