Aldos 1075

Shane Wink

Shane Wink

Well-Known Member
I purchased some of Aldos 1075 and have read it is different than the 1075 sold by admiral in that it has lower manganese. How do I normalize and heat treat it in an oven or rather what temps do I use?

I forged the 10" bowie already, its coated with pbc in the pic, but need to soften it a bit and normalize before grinding. I remember reading that a few heats to 1250 - 1300 will soften the steel without doing a full anneal and cooling in the oven, is this true for Aldos 1075 as well?

Doing a few searches brings up information on admiral steels 1075 but not aldos and I want to be sure how to do it properly.

20130114_083739.jpg
 
Shane,

The low magnese content isn't going to change your procedure for temps etc.

It's true that multiple heats at 1250-1300 will "soften" your steel this method is for folks with a forge and no oven to hold accurate temps. This is how to spheroidize without an oven.

To spheroidize with your oven- Bring oven up to 1200 THEN put the blade in and soak for 1 hour. Then remove blade and let it air cool. This will give you a fully spheroidized structure which is what you are after. Many folks will refer to this heat cycle as a "sub-critical anneal"

I speroidized after rough grinding when my blade is ready to be hardened. It's fine to do it on your rough forging but I'd recommend also doing this again before your hardening cycle. Spheroidizing will leave your blade without any internal stresses from the grinding process and will reduce the chance of a warped blade from the quench.

Hope this helps :)

Edited to add- For a better understanding of what Sheroidizing means visit Kevin Cashen's website. Click this link and scroll down to "Sheroidal Carbide"-
http://www.cashenblades.com/metallurgy.html
 
Last edited:
Thanks Josh. I have read Kevins post on the link you provided but had forgotten it as I have read so much of his stuff, thank you.

Bring a hypoeructoid steel I am guessing it needs a slightly higher austenizing temp, say 1550?
 
Shane,

Being a Hypo 1075 will not have any leftover carbon once hardened so we don't have to worry about putting too much carbon into solution with higher temps on the hardening heat. The higher the heat-the more carbon that will be put into solution.

As such higher temps are ok but 1550 is too high.

1500 will be sufficient to get to the full hardness available with 1075.

We never want to go hotter than needed for a particular steel. Getting the steel too hot will lead to grain growth which is detrimental.

I cannot say at what temp grain growth will begin. I can say that this temp is a moving target based on how fine the grain is. The finer the grain, the lower the temp that the grains will start to grow.

In a nutshell, I'd stick with 1500 for hardening heat UNLESS I was shooting for hamon. In that case I'd lower my temp to 1450 for hardening.


-Josh
 
Its all good Kevin , thanks. I knocked the little bit of scale that was on it off with an old belt and checked it for hammer marks. Then followed the advice on the speroidizing that Josh provided and cleaned it up to 220 grit afterwards. I will do 2 more thermal cycles next week when I have a bit more time to play with my own knives but I was able to get just one in this evening.

Dan Graves had challenged me to forge and grind a 10" bowie. He is right that big bowies are like potato chips, you cant build just one! I have not used 1075 before so it will be fun to see how it compares to the 1095 and 1084 blades I am building.

20130114_172730.jpg
 
Thanks but the blade was forged just to see how my skill has progressed at the forge and to be used as a template for a customers knife that I will be starting on next month. I wanted to heat treat the blade to try it out is all. 1075 was all I had in stock that was thick enough to forge.
 
You must log in or register to reply here.
Back
Top