Is Aldo's 1084 extra spicy or sumpin?

[Rick Marchand]

Some set up info first....

I was using 5160 and 1070/80 from Admiral for the longest time. I heat treat in my gas forge. I have a thickwalled pipe and let the forge whisper at 2-3psi, where the thermocouple reads 1500-1550F throughout. My tempering was best at about 385-400F or a dark straw colour. I use a toaster oven and have 2 anolog thermometers... one at the front and one at the back. (they are usually between 15degrees of eachother. The blades lay on the middle rack on ceramic bricks.

Aldo's 1084 has me tempering at 425F to get the same hardness. I understand that the higher carbon content make for a harder "as quenched" rockwell... but what scares me, is the pieces are turning blue during the temper. I thought that happened around the 500F mark. The hardness seems fine, but whats up wit dat?

Thoughts?

Rick

 

[mete]

Temper colors are not exact ! They depend on temperature , alloy , and surface condition such as contaminants like oil.

 

[Rick Marchand]

I figured that... must be the alloying... i haven't changed anything else but bumping the temp 25degs. I have done a dozen or so blades of Aldo's 1084 with the same result.

Thanks, Mete

***** edit to add*****

Perhaps my scotchbrite wheel has reached it's critical point of contaminant saturation.... I use it to clean up everything, including the blades prior to tempering.... hmmmmmm?

Rick

 

[sunshadow]

If you look at the chemistry of Aldo's 1084 it has always been a little spicy, the manganese makes it deep hardening, the vanadium pins your grain boundaries to keep your grains from blowing up, and there's just enough extra carbon in there to keep it perfectly eutechtoid after the vanadium takes it's share of the carbon away. I got some of that 1070/1080 from Admiral before I tried Aldo's first 1084 offering, and the stuff Admiral sells is overpriced crap in my opinion. Once I tried Aldo's 1084 I have bought at least 100 pounds from each batch, more when I could because the stuff is fantastic!

Don't freak out about the surface temper color

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