Thread: RSO # 1

Originally Posted by bluesman7

I am under the impression that 01 benefits by a 10 minute soak at austenitizing temperature before quenching.

If you have very good temperature controls a ten minute soak will not do any damage. If your temperature controls are, um, looser then you'd like a few minutes, five would be better and ten maybe too long. I'm using salt baths so I'm spoilt by my equipment. A five minute austenitizing soak is what I think is the minimum to ensure all the carbon goes into solution. All that means that the heat is set for the correct solution temperature for the steel being heat treated. This does not include any preheat cycles or ramping steps required.

And so, "It depends."

By good control, I mean a stable holding temperature with adequate thermal mass that adding a cold/cooler than forge temperature object you don't suck the temps down and have to wait for the heat to settle back to the set point.

By looser controls, I think of a charcoal or coal fire where there are part of the heat that are hotter or less hot. The pipe trick really smooths out a lot of those problems but still lets you use natural fuels. LP fires almost need some sort of means to test temperatures, then adjust the air/gas mix until a stable heat/temp can be predictably controlled. The wrong mix even for holding temperature may mean the risk of excess scale formation too. Loose controls on LP fires usually mean catching the right temperature as the heat either rises up through the correct temperature or falls down through that temperature. That's where you might not have a few minutes at the right temperature. A fast rising heat can push the blade up into the coarsening temperatures and you lose any hope of grain control.

Always: learn the heat you have. It means making a lot more blades than you thought to find out what you want to really know. I hope this example makes sense anyway.