Blade temper question

[Spyder59]

If a 9cr18mov steel knife blade if heated in an oven to 300 degrees for thirty minutes will it negatively affect the factory temper?

 

[Rapt_up]

Depends on what temperature it was tempered at from the factory... If it was lower than 300 yes. If it was more, no.

 

[David Martin]

Though I've not worked that steel. I have to say in general it could lower the blades hardness a point. Which would just give the blade better toughness. You can easily add this back if you wanted. DM

 

[Spyder59]

Though I've not worked that steel. I have to say in general it could lower the blades hardness a point. Which would just give the blade better toughness. You can easily add this back if you wanted. DM

That makes sense. I'm just going to use it for a while see what I can discern. The recommendation for optimum results for this steel is to temper at 150 C - 200 C for two hours. Converted from Celsius to Fahrenheit, that's nearly 300 F to nearly 400 F. I think the blade in question will be ok.

 

[DeadboxHero]

What's the objective here?

 

[Bo T]

Kitchen ovens can vary in their real vs labeled temperatures. And radiative heating from glowing elements can increase the temperature of the blade above the thermometer or thermistor readout temperature. If the blade was originally tempered at 300 F, an increase above that point could cause more loss.