I don't get this O1 steel

[lyuv]

I thought it was simple steel to work with. Good for beginners.

I found that if I heat my piece (6-7mm bar) to welding temperature, it will AIR harden. But at regular forging temp it will not. And I always "knew" it needed oil quench to harden.

Worse yet - as that air hardened piece cooled slowly in the air, it developed multiple cracks along the edges.

This has happened with several pieces, from 2 different batches.

Thoughts? suggestions? (I realy want to work with this steel, including forge welding it).

[DuEulear]

O1 will air harden in thin enough crosssection it is a really good blade steel and quite forgiving but like all toolsteel it has to be forged only in the right tempature range or you can crack it it also has a high temp range and a low temp (austinite) forging where you never heat above a blood red . Takes forever but it dose seem to increase edge retention. Of you arent a masichist try not to over heat the blade but whatever you do dont hit it below critical temp or you will lickley crack it

[Gerald Boggs]

My recommendation is to stop using O-1.  O-1 is good steel, both for knifes and chisels, but requires precise temperatures in all steps during forging and heat treatment.  Unless you have the equipment to do that, you will not get the benefits of using O-1.  Since most of the time, it's more expensive W-1, it's better to use W-1 or one of the other simple carbon steels.  I've also found 5160 to be a generally good steel for knife blades and forgiving in the forging process.  Both W-1 and 5160 forge weld to mild.

[Steve Sells]

i know its been said before , but I really suggest that you read some of the posts in knife making, it will save you heart ache and money

 Generaly O1 is lovely steel to work, but not if you dont know about the forging or welding ranges it will also harden sitting on a anvil  if you leave it there too long

[Will W.]

O-1, in my personal experience, is not too hard to weld. Tricky, but not difficult. During the actual welding, never let it drop below orange-red, and when welding is all said and done and youre forging your blade, never let it lose color (dont go below red, definitely dont hit it below red.) When forging is finished, allow it to slowly cool, similarly to annealing. Just leave it in your forge and turn the fuel off, or if youre using solid fuel, leave it in the fire and just let it go out. 

[Gerald Boggs]

I agree, it is as easy to weld as other tool steels. 

[lyuv]

Quote

 

Thanks guys. First, good to know I"m not crazy, and there IS an issue with heat treatment and air hardening. Lesson learned. I would love to have simpler steel, but around here, O1 is the only steel available to the consumer (other than rebars...). I can get other steels only by mail from abroad. VERY expensive.

I still cant weld it. When substituting with other steel the weld takes. Had this in several attempts. Could it be that using manual hammer is the problem? I guess press or power hammer (which I dont have) provides more preasure/time.

[Will W.]

People have been forge welding by hand for as long as our species has worked iron (literally thousands of years.) That is not the problem. 

[lyuv]

24 minutes ago, Will W. said:

People have been forge welding by hand for as long as our species has worked iron (literally thousands of years.) That is not the problem. 

That's true, and I forge weld by hand as well. I was reffering to my difficulty with O1. I read somewhere that the chromium in it creates oxidation that is tougher on the flux than the "regular" iron oxide. Therefore I wonder if it takes greater measures to weld O1 than a hammer.

[Will W.]

O1 typically has half a percent of chromium in its matrix, its a very miniscule amount. I dont beleive its enough to inhibit a weld, so long as your pieces are very clean, up to temp, and properly fluxed. 

I have welded o1 numerous times by hand. I assure you, it does not take greater measures to do it. 

[ThomasPowers]

"O1 is the only steel available to the consumer"  Shocked am I that Israel has no cars with leaf springs and axles to supply 5160 and 1050.

If you are trying to weld O1 to itself and are having trouble try slipping a piece of pallet strapping between them and see if that will weld up easier for you.

[lyuv]

3 hours ago, ThomasPowers said:

"O1 is the only steel available to the consumer"  Shocked am I that Israel has no cars with leaf springs and axles to supply 5160 and 1050.

Actualy, cars here do have springs. But I found out that the cars owners have guns or big dogs and that I"m alergic to both. Beside, used springs are sort of "mystery steel". They ARE good as general  hardenable steel. But not if I want a KNOWN steel.

I consider buying NEW car leaf spring from a local manufacturer, but I never heard of the steels he uses (sae9260, sae6150) in blacksmithing/bladesmithing context. 

[ThomasPowers]

good for large tough blades in particular, and buying new steel drops from a spring maker is a much better method than sourcing them at scrap yards.  As in intermediate method here we have places that raise or lower or modify vehicles for special use and often will junk brand new springs. The one I used to use the springs had 16 miles of use on them---the distance from the vehicle dealership to the shop where they modified trucks into ER vehicles.