Thread: The best heat treatment for Suminagashi Steel

Originally Posted by gregg71

Hi,

thank you so much for the quick answer.
What speed has this oil what you use? Why did you change from canolia if it is worked for you?

To be honest, I dont know it. I changed, because my workshop smelled always like a french fries restaurant, after the hardening and heat treatment. I using an old friteuse for the process. I hoped the new oil will reduce this. It will... now it smells more like a overheat motor

How much time soaking: 4-5 mins? --> yes

Cooling down on the aire to room temperature or how many? --> I dont know exactlly. I wait approx. 1 min. before I will put it back in the oven. This is pendular tempering to remove stress from the steel and make a finer grain.

Thank you so much for your response! You have given me a new hope.

I would go a little higher with the steel temperature. 825. And a shorter soak.
Your oil is just fine. The cheapest corn oil will do.
Also, how quickly do you get from the oven to the quench? This is shallow hardening steel so any drop in temperature below critical will greatly affect performance.

[QUOTE=gregg71;1628406] Sometimes the steel is colorised to blue and brown. I did not make normalizing because I am not forging. [QUOTE]
I personally think this may be your cause right here

I haven't used any laminated (welded) steels yet, but my understanding is you need to always stress relieve/normalize after grinding whether forged or stock removal, for this very reason as the grinding process creates stresses in mono steel let alone the laminated steels

Thanks, Bruno, I will try!

Originally Posted by Bruno

Also, how quickly do you get from the oven to the quench? This is shallow hardening steel so any drop in temperature below critical will greatly affect performance.

In one second.

Originally Posted by gregg71

Sometimes the steel is colorised to blue and brown. I did not make normalizing because I am not forging.

I personally think this may be your cause right here

I haven't used any laminated (welded) steels yet, but my understanding is you need to always stress relieve/normalize after grinding whether forged or stock removal, for this very reason as the grinding process creates stresses in mono steel let alone the laminated steels

Thanks, but I made around 15 razors without any problem. The only differnce is maybe I use a very speed grinding method with clamps nowadays. I dont know.