knife from 2235 - error prevention

[Indianer]

Hey guys- I wish to forge a knife, a buplicate of an icon weapon from a favorite game series.

With my propane tank forge I started drawing out a bar of 1.2235 (data sheet) I had laying around. It was far too broad (about double of what I needed), yet too short. The thickness was in the range.

I built a tentative makeshift device to help draw it out. An expansion tool for the railroad anvil I have. I goes well...ish.

First: What makes me worry though is that I already got 4-5 hours in drawing it out, and I´ll do it for another afternoon till the width is down to what I need for the blade. Is that very bad..? On the bright side, the piece is pretty straight and of uniform thickness as of yet...I am pleased with that.

Second, I am working a high-carbon alloy. I have seen Alec Steele forge metal that was well below glowing temp - he finished the shape of tips on a rod (here, from 3.20 onward, or 5.25 onward). Now my stock is much more massiv, and probably higher in carbon (0.8). Will it damage the metal if still work my stock at a temp of 1000-1100F? (my reference heat colour chart) It cools rather quickly, and it´s easy to drop the hammer once too often during cleanup after the "let´s draw it out some" part of a heat...much as I try not to do it.

Third: Thank you. For this, and anything else you can tell me on the project.

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I read Jim Hrisoulas Book "The complete Bladesmith" carefully, and did lots of other research, esp. on hardening theory and practises. Though my focus is largely on making armor. I watched the entire "Men at arms- reforged" series on youtube and screenshotted and catalogue pictures of steel glowing at hardening heat. I also watched some instructional videos of Alec Steele and others on basic smithing techniques. In short: I learned and noted, for years, to avoid errors. Whatever I do wrong now I am sorry about, yet probably unable to correct on my own.

[Irondragon Forge ClayWorks]

I can tell you that this is posted in the wrong section and will probably be moved. Have you read this? READ THIS FIRST

[Indianer]

Hello IronDragon. Yes, I did. I also read " Common Basic Mistakes That Beginners Should Avoid". I tried google for information on 2235 forging temp. All I ever find though is the heat treating details. Not quite sure what to search instead without derailing.

[Irondragon Forge ClayWorks]

I see that it's been moved from General Blacksmithing  to Knife Making, probably a better section to get good answers. As far as forging temp that's listed in the data sheet.

Forging

( Hot forming temperature: 1050-850^oC.) don't know what else you need.

BTW, if you edit your profile to show location, we won't have to ask you for it when the answers need to know where in the world you are located.
 

[Indianer]

2 minutes ago, Irondragon Forge & Clay said:

( Hot forming temperature: 1050-850^oC.) don't know what else you need. 

Alright...my bad. I read several sheets, overlooked it here. Thank you. I will not touch it then in the red ranges. Jim Hrisoulas specifically mentioned doing exactly that though, naming it "Aus(tenite)-forging": Working below the critical temp, mostly in dark/dull cherry red. He doesn´t get specific on steels that can endure that. I planned on applying that for the cutting edge. It is supposed to restrict grain growth.

If a quick answer is legit: Leave be, or is it ok?

[Steve Sells]

not all steels allow ausforging

[pnut]

Jack Andrews book "New Edge of the Anvil" has a pretty easy to understand section on metalurgy for the blacksmith that explains austenitic and martensitic, the different phases of metals at different temps etc. It cleared up a lot of things for me. You may want to give it a read if you haven't already.

Pnut

[Indianer]

pnut, thank you kindly. I will keep my eyes peeled for that. For now, I assume the concept of matrix transitions itself is clear enough. If not someone´s gonna tell me in response to the following question:

Having done more research I still can´t find one thing: Steve, thank you for the tip that some steels don´t stand ausforging. Now, is there a way to decide whether or not mine, or a steel in general, can?

Thank you!

[Steve Sells]

the mill sheets for a steel include forging temperatures. the highest temp range is for forge welding.  Then there may be two more sets of forging ranges,  the lowest set being for ausforging,   generally if there is a forging range listed that is lower than the Austinetic point that's the ausforging range

[Indianer]

Thank you!

[Latticino]

On 8/24/2019 at 6:12 PM, Irondragon Forge & Clay said:

Hot forming temperature: 1050-850^oC

Based on the range ID listed, I'm with Steve that you will need to avoid the red, ausforging range for this steel.  In my experience most mild steel can be forged down pretty cold, but the higher the carbon content the greater chance of cracking (red-short?) at low temperature forging.  Of course if you forge at too high a temperature for too long you are going to get bad grain growth, so be sure to thermocycle with reducing temperature "normalizing" and stress relief passes.  Not sure what you are using to measure the temperature of your steel.  If color, it can be deceptive depending on ambient lighting.  Also be aware that the color a video camera records during filming can be extremely misleading, so judging from YouTube videos can lead to problems.

[Indianer]

Latticino, thank you for your input and suggestions.

55 minutes ago, Latticino said:

Based on the range ID listed, I'm with Steve that you will need to avoid the red, ausforging range for this steel.

I will avoid it. Since there are, in contrast to Steve's description, not three ranges, but just the one listed, I assumed ausforging was not advised here. This one also starts above the Curie temp.

 

55 minutes ago, Latticino said:

In my experience most mild steel can be forged down pretty cold, but the higher the carbon content the greater chance of cracking (red-short?) at low temperature forging.

Did I get my terminology mixed up? For red-short I have noted this (which tells me that, paradoxically, temperatures above red get increasingly detrimental):

Red-Short: Quality iron or steel at and above 900°F/460°C becomes increasingly malleable and plastic. Iron or steel having too much sulfur becomes crumbly and brittle though. This is due to sulfur forming iron sulfide/iron mixtures which have a lower melting point than the steel. These alloys form in the grain boundaries. When the steel is heated up further, the FeS begins to melt, separating the steel there. Fabricators add Mn to the steel when it is produced to form manganese sulfide. MnS inclusions have a higher melting point and do not concentrate at the grain boundaries.

EDIT: I also noted that, since modern stock is rather pure, the infamous sulfur might be introduced by coal forges, not propane forges. Which means I´d be safe from that phenomenon.

 

55 minutes ago, Latticino said:

Not sure what you are using to measure the temperature of your steel...

Indeed, I go by eye. I am working in a shed, the propane forge standing outside. The world outside the shed is far too bright for my taste...I try to learn to counter-guess it right. The shed itself seems dark enough. I was planning on, from now on, also use a thermometer (one such metal rod thingy, not infrared). I am not quite sure though if the steel might get much hotter than the air inside the forge, which would render that thing useless. Any experience with that?

Best, Indi

[JHCC]

No, you are correct about red shortness: while it originally referred to this cracking problem with high sulfur content, it can also (more or less) apply to similar effects in forging high end alloy steels at excessive temperature  where the alloying elements similarly migrate to the grain boundaries when they reach their melting temperature. For example, O-1 will crack if forged in the light yellow and higher range. 

[Latticino]

That's why I put a question mark after it as I wasn't clear on the terminology. Thanks for researching and correcting.

[JHCC]

No worries. I only figured it out myself a couple of months ago (trying to figure out why O-1 was crumbling on me).

1 hour ago, Indianer said:

EDIT: I also noted that, since modern stock is rather pure, the infamous sulfur might be introduced by coal forges, not propane forges. Which means I´d be safe from that phenomenon.

The sulfur in red-short steel comes from the parent ore, not from the forging heat. The way that modern metallurgy handles the excess sulfur is through the addition of manganese. That way, instead of the sulfur migrating to the grain boundaries, it binds to the manganese to form manganese sulfide, whose melting temperature is sufficiently higher than iron's.

[ThomasPowers]

Not the ore; the blast furnace fuel; Coked coal may still contain sulfur and contribute it to the steel---why the *best* steel for 200+ years was the swedish CHARCOAL smelted steel they still made after other places went to using coke.

[Indianer]

Thank you guys for the continued elaborations here. I am still following. 

I am currently fashioning a crude addition to my propane forge - a simple assembly holding a neodymium magnet in front of and below the forge opening, encaged in a small cage of wire mesh. The magnet will tell me when I´ve reached the curie temp. The mesh is to serve as spacer to prevent overheating. When not probing the work piece with it the caged magnet will be submerged in a bowl with water.

I really have no idea if that is going to work...might be the magnet still overheats to quickly when probing the steel, which will destroy it permanently afaik...keeping you posted.  Indi

[Steve Sells]

You are over thinking this, First the magnet wont be a magnet after it gets hot from the dragons breath,  Second you just touch the heated piece to see it it is attracted, Third any cheap frige magnet on a string will work fine.

[Irondragon Forge ClayWorks]

4 hours ago, Steve Sells said:

frige magnet on a string

That way the magnet doesn't touch the steel, if it's drawn to the steel it's not hot enough.

[Frosty]

I use my mechanic's pocket, screw starter fishing magnet. Holding it between two fingers by the end amplifies the feel of any attraction so it makes a fine tester. I've hung a horse shoe magnet on a piece of wire to good effect too. I prefer not having to get my delicate fingers too close to critical temp steel.

Frosty The Lucky.

[Indianer]

Hello Frosty, by "screw starter fishing magnet" do you mean something like this? I can´t do a direct translation on that one.

Today I narrowed the stock down further - nearly done with that. Steve was right, I don´t need much of a jig, the magnet-in-a-mesh hung on a wire worked...crudely, but it worked. During the recent research I discovered recalescence as a useful indicator. Played around with that and the magnet. Turns out, I´ve been higher in the lower temps than I thought during the last session, which is good.

Next is forging the bar into a blade... so long.

[Frosty]

3 hours ago, Indianer said:

Hello Frosty, by "screw starter fishing magnet" do you mean something like this? I can´t do a direct translation on that one.

Nope, search "KD tools, 2282 slotted screw starter with pocket clip." It's the first closest my GoogleFu turned up. Mine has to be at least 40 years old and I don't remember where I got it, heck it might even be a Snap On! Like that's likely I was almost living hand to mouth when I was turning wrenches under car hoods. That new generation KD starter is WAY nicer than my old one it only starts slotted screws and that's all unlike these new fangled ones. 

A fishing magnet like you posted will work just fine and the telescoping handle lets you get farther from the HOT steel.

Frosty The Lucky.

[Indianer]

So, I am getting ahead of the process a bit, but this still needs to be learned. I have been searching for the proper quenching medium for 2235/80CrV2. I came up with this thread, the last post seems reliable. It suggests quenching with Canola Oil (120°F). Any objections or other suggestions? Thank you!

Best, Indi

[Frosty]

Forge a test coupon of your steel and test it's reaction to warm Canola oil. If you forge it down to say 2 mm. and 30 - 40 mm. long you can test the quench on the whole length. Then by warming one end and allowing the temper colors run part way down it's length you can test for the best temper for your project. 

Once quenched you place the coupon in the vise with the hardened end sticking a little way, cover with a rag (in case it shatters) and give it a rap with a hammer to determine how brittle it is. Then progress with the same method through the temper colors till you have a good idea of how the steel performs at each.

Make sense?

Frosty The Lucky.

[Indianer]

Will do that! thx mate!