Damascus metals, how is spring steel to work with?

[P. Bedard]

I just got a nice gift of some high carbon steel including some offcuts of car leaf-springs, some 4140 steel, some 4340, some S7, some A2, and something marked SPS (no idea what it is and I can't find it on the web).

So, do you recommend a spring steel/mild steel combination for damascus? If not, what do you recommend instead?
Thanks for the input!

Edited January 31, 2009 by Spikeknife
More types of steel than I thought.

[Woody]

I don't recommend it, mild steel does not have enough carbon in it to be hardened sufficiently for a knife blade. A lot of people use a plain high carbon steel like 1095 and a nickel steel like 15N20 or L-6 for damascus. This gives a lot of contrast when etched.

[Graham Fredeen]

It depends on your plans for the blade/billet. You could use mild in the mix if you were doing a multi bar billet with high carbon billet edge wrap (like the old viking style pattern welding), or if you did san mai (taking a piece of high carbon and forge welding your damascus billets around the outside, thus when you grind, the high carbon is exposed at the edge). But if you don't plan on doing one of these methods, the blade you get will not be able to be used. As Woody said, the mild wont harden so you will have soft layers exposed at the edge of your blade. Better to choose steels that will harden sufficiently for the blade. The 1095 and 15N20/L6 mix Woody recomended is very nice (1095 will etch black, and the nickel in the 15N20 will leave it silver giving huge contrast) and something I use alot in my damascus.

Also, 5160 (spring steel) can be a bit more challenging to forge weld if you arent good at forge welding yet, so might want to get some practice and get comfortable with forge welding before trying to mess with too much of that.

Forgot to mention, its also important to choose steels that are somewhat simiar/compatable with each other. You want to find steels that have similar critical temps, similar quenching procedures, similar hardening characteristics, etc. Otherwise you can have billets pull apart in HT since certain steels expand at different rates.

Edited February 1, 2009 by TarAlderion

[P. Bedard]

Thanks for the advice! Hopefully I'll be able to get some scraps and give it a try.

[ThomasPowers]

About 20 years ago Daryl Meier, as part of the Damascus Research Group at the Southern Illinois University Carbondale, showed that unless you have a carbon migration blocker like pure nickel, the carbon content of a pattern welded billet will equalize after a fairly low number of times to welding temp---4 was the number mentioned for the size of stock I use.

So the problem is not un-hardened layers at the edge; the problem is that low carbon steel drags down the total ammount of carbon in the billet and so can make it lower than wanted for a blade.

This can be dealt with by using all higher carbon steels, or using quite high carbon steels as "donors". (I will sometimes use a 1.2% C steel if I'm using a low carbon material like wrought iron in a billet). Another method is to make the high carbon stock much thicker than the low carbon stock so the "mix" tends toward the higher end.

To get non-hardenable layers on the edge you can put in something that doesn't harden---like Ni or use Ni to keep carbon migration from happening.

[trying-it]

A little additional information for clarity:

The Damascus Research Team at Southern Illinois University in Carbondale comprised of Robert Griffith, Jim Wallace and Daryl Meier. Brent Kington founded that particular educational program and department. The time frame for their conducted research was actually in late 1960's - early 1970's.

I know Daryl, Jim, and Brent quite well and consider them all as dear friends.

This old man was fortunate enough to play in that SIUC smithy for a few semesters (as elective classes) during my recent pursuit of higher education.

[brucegodlesky]

Interesting stuff, Thomas and Tom. Thanks

[julian]

as was before mentioned, mild steel *can* be used in a blade billet, but it will suck up carbon and you'll have to avoid having it on the cutting edge.

I've used spring steel in laminated steel before, and I didn't run into any sort of problems welding or working with it. What you will have to look out for is combining steels that cool in different ways or behave differently at high temperatures. Putting an air cooling steel that crumbles at high temp in your billet can be very tricky.

Just take a bunch of steel you have laying around, tack it together, weld it up, and see what happens. Don't be afraid to use scrap steel for practice!

[781]

I have used leaf spring and large ball bearing rollers with a nice contrast