How long in between grain refinement cycles

[PaulDiStefano]

hey guys, so I have been forging my w2 knives and have been normalizing at 1650 and staying at temp for usually around 3-4 minutes then take it out and leave it until all the red glow goes away. I keep reading people say cool to black so I think that's what they mean? And then 1550-1450-1350.
My question is how long should I keep the blade in my evenheat oven at each cycle temp and how long should I keep the blade out to cool between each cycle? Should I let it cool until all the red glow is gone and start next cycle or should I Wait until all glow is gone and quench in my parks or water and then continue at the next lower temp?
I keep reading dozens of threads where I keep seeing different processes I don't know which one is best.
Thanks guys

 

[E.Carlson]

I think 3 of 4 minutes at each temp is plenty. The first time I did it I did a 15 minute soak at each temp and ended up with a huge decarb layer.
Cool to black in dim light, a quench after its black can be done but isn't needed.

 

[Stacy E. Apelt - Bladesmith]

In a forge, I just hold it there for a minute or two and take out. I watch it cool off, and when there is nothing but a black look, I either dip in water t cool, or stick back in the forge to bring up to the next step. It is hit or miss when doing it by eye in a flame, but with experience you can get a pretty good grain refinement and stress relief. The last cycle of the refinement ( 1450), I quench the blade to convert it to martensite. That is a better starting platform for the final austenitization and hardening quench.

When using an oven, the simplest way is to program the steps and use 5-10 minute hold time. Use the alarm function if you have one or set a timer. Take out the blade when the cycle is done and set on a firebrick to cool. When the oven has dropped to the next level, put back in for 5-10 minutes and repeat for each subsequent drop. As with the forge, quench from the 1450 soak.
When the blade is done with the refinement and straight, do the hardening austenitization and final quench.
BTW, you can straighten any warp between the steps once it drops to black.

 

[PaulDiStefano]

In a forge, I just hold it there for a minute or two and take out. I watch it cool off, and when there is nothing but a black look, I either dip in water t cool, or stick back in the forge to bring up to the next step. It is hit or miss when doing it by eye in a flame, but with experience you can get a pretty good grain refinement and stress relief. The last cycle of the refinement ( 1450), I quench the blade to convert it to martensite. That is a better starting platform for the final austenitization and hardening quench.

When using an oven, the simplest way is to program the steps and use 5-10 minute hold time. Use the alarm function if you have one or set a timer. Take out the blade when the cycle is done and set on a firebrick to cool. When the oven has dropped to the next level, put back in for 5-10 minutes and repeat for each subsequent drop. As with the forge, quench from the 1450 soak.
When the blade is done with the refinement and straight, do the hardening austenitization and final quench.
BTW, you can straighten any warp between the steps once it drops to black.

I have been normalizing and refining right after I forge and then I grind then clay the blade for hamon soak and quench. Is it better to forge, grind, then grain refinement cycles, quench on last cycle and then clay and final quench. Will there be decarb on the blade after these cycles that will interfere with the hamon pattern. Or should I quench in last cycle then clean the blade up a bit in grinder then clay for hamon and final quench.
I hope I made sense there.
Thanks Stacy

 

[Willie71]

I do a 10 min hold at temp, and cool to black between cycles. This is the perfect time to trust a magnet. The steel is cycled cool enough when the magnet sticks again. It can go right back into the next heat at that point.

 

[PaulDiStefano]

I do a 10 min hold at temp, and cool to black between cycles. This is the perfect time to trust a magnet. The steel is cycled cool enough when the magnet sticks again. It can go right back into the next heat at that point.

Oh ok thanks for the info. I didn't know it could go back in that fast. I thought it had to drop a lot lower.

Thanks everyone for your help

 

[Stacy E. Apelt - Bladesmith]

It only needs to drop down into the pearlite range .... around 900F. In practicality, if it drops to magnetic (1250) it can go back, but most folks take it to black.