1084 vs 1095

[Eli Jensen]

I've been getting 1084 from Aldo, but it appears he is out of stock, at least online. I am not a fan of the new website, at all. He does have 1095, more expensive though.

1) What are the benefits of 1095 over 1084?

2) How does the HT differ?

Thanks

[Doug Lester]

Check the specs for it but I don't think the 1095 that he carries has that tough of vanadium in it which would increase the depth of hardening just a little. I would use the same heat treatment for the 1095 as I did for the 1084 and test. Both are rather basic hypereutectic steels that could profit from a short soak though most of the carbides formed is cementite which will dissolve rather easily.

Doug

[Kevin R. Cashen]

Advantages of 1095- extra carbide
Disadvantages of 1095- extra carbide

Advantages of 1084- much wider margin of error in heat treating.
Disadvantages -? let me think on it a bit.

It doesn?t seem like much but that small percentage more carbon in the 1095 will make a big difference in the way you approach heat treating it. That extra carbon will give you an edge in abrasion resistance (one key facet in edge holding) if you can put it in the right places at the right time, but if you can?t do this that extra carbon will be a liability. The largest differences in heat treatment will be in the temperatures you heat to and how fast you cool from them.

For 1084 the temperature for hardening can range from 1450F to 1500F with little problem, with 1095 you need to stick as close to 1475f as you can. With the 1084 you can cool at almost any rate from above critical for annealing and other treatments not involving a quench, with 1095 you should avoid anything slower that open air whenever possible.

If it helps I have details on both at my site here:
http://www.cashenblades.com/heattreatment.html

[Eli Jensen]

Called Aldo, he had a little and hooked me up. Glad I called today, he's leaving tomorrow for Blade. Wish I could go. Going to try next year.

I might try 1095 after this batch. Need a more precise method of gauging temps to hit that narrower range. Or, a lot of experimenting. Or, more likely both.

So you cool 1095 in open air for annealing? And 1084 . . . vermiculite?

[Doug Lester]

That is a problem with using a hypereutectic steel for knife making. Even the simpler steels can need a little bit of a soak time which should be between A1 and Acm to help avoid slow grain growth. Unfortunately, there is not much of a difference between those temperatures even up to 1% carbon. Note that this only applies to the simpler spring and tool steels. Get into the more complex air quenching steels, especially those with significant tungsten and vanadium, those soaking temperature will have to he higher to dissolve the carbides of those metals. But those alloys will put a drag on grain growth.

That makes me wonder if the touch of vanadium that I understand is in Aldo's 1084 is more to put a drag on the grain growth than to provide vanadium carbides for wear resistance.

Doug

[Kevin R. Cashen]

Originally Posted by Eli Jensen

...So you cool 1095 in open air for annealing? And 1084 . . . vermiculite?

Not really. It is more in how high you heat it to anneal. With 1084 goign to nonmagnetic and then air cooling or even vermiculite is not an issue, but with 1095 if you heat it above nonmagnetic and put that extra carbon into solution, slow cooling will cause it to bunch up in ways that will be problematic. So for 1095 it is best to anneal by keeping it below the nonmagnetic point and allowing the carbon to ball up into little spheres, you can then cool any way you like.

[Eli Jensen]

You metullargy guys sure are cool. I hope one day to be able to wrap my head around that stuff so well.

[hawk45]

I'm with ya brother.. went out to Aldo's to get some more 1084 and no go. I was going to grab some 1075 but no go either. Being that I want to do my own heat treats in a homemade coal forge the 1095 is a little scary..er..

Going to nonmagnetic with the 1075/84 is a pretty easy way to HT. So am I understanding the with 1095 you want to bring it to just under non-magnetic before quench? Seems like everybody does things different.

[Doug Lester]

Looks like Aldo might need to see about getting some more steel made for him.

Doug

[Kevin R. Cashen]

Originally Posted by hawk45

... So am I understanding the with 1095 you want to bring it to just under non-magnetic before quench? Seems like everybody does things different.

Nope, annealing and hardening are two different things. The subcritical anneal will take carbon out of solution, the hardening heat will put it into solution so you can trap it there. So the hardening heat will be above non-magnetic- 1475F. You just don't want to put too much of that carbon into solution or you will get poor results from the quench, thus 1095 has a narrower window to shoot for in your margin for error.

[hawk45]

Originally Posted by Kevin R. Cashen

Nope, annealing and hardening are two different things. The subcritical anneal will take carbon out of solution, the hardening heat will put it into solution so you can trap it there. So the hardening heat will be above non-magnetic- 1475F. You just don't want to put too much of that carbon into solution or you will get poor results from the quench, thus 1095 has a narrower window to shoot for in your margin for error.

Thanks Kevin, good simple explanation. Cheers!