A question about grain growth

[Jonas Liebel]

Hey there folks,

I was just heat treating some blades in my gas forge, and i managed to overheat a few of them while heating them up ( they were glowing yellow in darkness).
I didn't quench at that temperature, I just put them back in and let them get down to a bright orange colour.
Now, I know that if you quench steel at a temperature that is too high, the grain size will grow significantly, but what about if I overheat it for 20 seconds or so and then bring it back to the desired quenching temperature?

Or in other words, should I requench those blades that got bright yellow for a moment?

Thanks guys

 

[DevinT]

What steel are we talking about here?

Hoss

 

[Larrin]

The grain growth occurs at temperature not during quenching.

 

[Ian Fifelski]

The grain size, like Larrin said, grows at the high temp, so even if you quenched at a correct heat, the grain size had already been enlarged. So yes, to get a smaller grain size, normalize and requench.

Just figured out what your profile image is btw.