Overheated car spring

[Joel OF]

I've read that car spring steel and steel of a similar carbon content shouldn't be heated above red/orange, if it has been is there any way of undoing the mistake? Higher carbon steel feels a lot harder to work with than mild steel, logic says heat it up more so it's easier to work with but if I shouldn't heat it up beyond red/orange, is hitting harder my only option?

[John B]

I've read that car spring steel and steel of a similar carbon content shouldn't be heated above red/orange, if it has been is there any way of undoing the mistake?

 

Depends on your interpretation of red/orange, it should also not be be forged when below a dull red,

 

These colours are guides, and experience will tell you what degree of colour is involved,

 

With regards to the 'mistake' and correcting it, that depends on how the mistake manifests itself as to what action you need to take to correct or abort and try again.

 

 

Higher carbon steel feels a lot harder to work with than mild steel, logic says heat it up more so it's easier to work with but if I shouldn't heat it up beyond red/orange, is hitting harder my only option?

 

High carbon steels and alloy tool steeels are harder to forge than lower carbon (mild) steels,

 

Take your logic and keep it heating it and you can recast it, that does not work either

 

So hitting harder, hitting more frequently, and hitting within the correct forging heat range all help,

 

If you are going to be forging tooling steels on a regular basis consider investing in a mechanical or air hammer

[Joel OF]

What does "recast" mean? I won't be using tool steel often, I just have some car springs which I wanted to make chisels/punches/drifts/hardy tools out of. I had a design for a hardy tool in mind, (which would require doubling the spring back on itself to make it fit snugly into the hardy hole), but if I shouldn't heat the steel beyond orange then it's probably not a good design as it'll take forever to forge.

[thingmaker3]

What does "recast" mean?

It means "melt it and pour it into a mold."

 

If alloy steel is overheated, the grain becomes unacceptably large. If this it the only problem, we can fix it by thermally cycling the steel. Some steels will have elements coming out of solution at the grain boundaries when overheated. This can make the steel come apart at the seams, so to speak. D2 is one example - hit it when it is too hot and you'll shatter it. Some steels will remain brittle because of this even after being tempered.

 

Overheating also causes rapid decarburization.

[John B]

What does "recast" mean? I won't be using tool steel often,

 

Just using it as a  "Logic" example, similar to if you bend something you can bend it back, things happen which you may not be aware of and they will affect the logic you may be using, which will then affect the outcome.

 

I just have some car springs which I wanted to make chisels/punches/drifts/hardy tools out of. I had a design for a hardy tool in mind, (which would require doubling the spring back on itself to make it fit snugly into the hardy hole), but if I shouldn't heat the steel beyond orange then it's probably not a good design as it'll take forever to forge.

 

Design may not be the problem, dedication, application and motivation may be.

 

Patience is the answer and it may take you longer than you would like, but it can be done.

 

Try playing with a bit of the material first to get experience of the heat you can use that works OK. then put a coulour shade in your own mind for that situation.

[John B]

What does "recast" mean? I won't be using tool steel often,

 

I think thingmaker has explained that for you.

I had a design for a hardy tool in mind, (which would require doubling the spring back on itself to make it fit snugly into the hardy hole), but if I shouldn't heat the steel beyond orange then it's probably not a good design as it'll take forever to forge.

 

An optional design may be easier if the spring is quite thick, make it to fit your hardie hole diagonally across the corners,

 

Then you don't need to forge it if its too much like hard work, you can just use an angle grinder and cutting disc, or anneal, and saw/file the profile to shape

[Rich Hale]

The problem youiare dealing with shows itself as large grain structure in a broken piece of metal, If youwant I willd etail a shop testing process here that will let yoiu see it in person..but not if you are not willing to put in the hours and work.

[Joel OF]

Design may not be the problem, dedication, application and motivation may be.

 

Patience is the answer and it may take you longer than you would like, but it can be done.

 

I didn't mean I can't be bothered, my "smithy" is at my parents place an hour's drive away so time (and diesel) is precious.

 

 

An optional design may be easier if the spring is quite thick, make it to fit your hardie hole diagonally across the corners,

I'd been considering that.

 

 

If youwant I willd etail a shop testing process here that will let yoiu see it in person..but not if you are not willing to put in the hours and work.

Thanks but save your breath, my brain's already a mush of info I'm struggling to take in.

[John B]

Thanks but save your breath, my brain's already a mush of info I'm struggling to take in.

 

Thats probably because you are trying to learn it from the internet, and you have no structure to what you are doing or where you are going, I would suggest taking a basic course, not just  "a day at the forge" but one with explaining the basic skills. Ask questions on the course by all means, but don't get distracted and "fireweld before you can forge a point" type of approach.

 

Blacksmithing is simple and logical in approach if not performance, its like anything, foundation first and build on that.

 

For example, and I am not shopping for students, and this could be a guide for others, our 3 day Intensive course covers

 

 

Introduction to;

· Personal Protection Equipment and the dangers of hot metal,

· The Forge hearth and types of forge,

· The Anvil, the various parts and their function, importance of stance and height

· Hammer Types

· Forging and Forming

· Use of and identifying tools and tooling

· Marking out

· Finishes

 

Skills used to make the items;

· Drawing down to a point (Square taper, octagonal, remove corners to round)

· Forging and controlling a flat taper ribbon end scroll / curl

· Bending and forming using basic tools and jigs

· Different hammer blows and their effective use

· The use of different parts of the anvil for fullering / drawing

· Use of hot cuts, hardies to split and cut off

· Twisting techniques and how to straighten and correct any inconsistency

· Punching round and square holes

· Upsetting / Jumping up

· Making Tenons and variations

· Use of Rivets and riveting

· Making and fitting Collars

 

producing these items,

 

 

You will then have some understanding and the ability to make reasonably complex items, gates, railings, frames, furniture etc,

 

Then you can move on to firewelding, toolmaking using different grades and types of steels etc, learn to crawl, then to walk then to run it will come together more easily then.

 

Good luck with sorting it, and enjoy the journey.

[thingmaker3]

 my "smithy" is at my parents place an hour's drive away

 

One of the biggest differences between Americans and Brits is this: A Brit thinks 100 miles is a long way and an American thinks 100 years is a long time. :D

[pkrankow]

I find coil spring moves easily at the right temperature. When it gets stiff it is too cold, and still glowing. It requires a few normalization cycles to refine the grain prior to hardening.

Too hot and it kicks off more than a spark or two, or crumbles. Start with more material than you need and DON'T BE AFRAID TO RUIN IT!!! Run it hotter and hotter until it misbehaves, then cut off the bad piece and try to get not quite that hot.

Diagonal fitting hot-cuts with a tapered shank made from leaf spring are rather nice. the tool can be pretty ugly and work great still. With a curved top they can cant in the hardy before jamming and still be easy to use. They also fit different anvils since they just seat differently.

Phil

[Hunterbow Smithy]

Kurgan,

 

If the steel has been over-heated as you suggest; you should be able to thermally cycle the material to refine the grain structure. The steel will need to be brought to a point slightly below the eutectic temperature (ie non-magnetic state) and then allowed to air cool. I would repeat the heating and air cooling proceedure 2 or 3 times. Also, you should try to figure out what type of spring steel you are dealing with....5160 or something else.

 

To visually see what happens and how the grain changes, heat a small portion of a bar of the spring steel to bright orange / yellow colour and then qench the tip in a bucket of water and break a small piece off on the edge of the anvil. The faces of the broken bits of steel should appear very rough and the grains very large. Then if you thermally cycle the very same bar and quench it and break off a piece, the faces of the broken pieces should appear fairly smooth, the grains small, and the face a dull colour. A note of CAUTION, wear eye protection or better yet a face shield when breaking off pieces of the steel as small shards could fly anywhere. Also, try to break the steel off at the quench line.

 

Good luck to you  

[Joel OF]

John, trust me I'd be there in a flash if I didn't have frustrating chronic health problems that makes things that like impossible, my only option until I'm better is to learn from books and forums. I'm considering asking for a few months unpaid leave to finally sort my health, give me the time to do such courses and spend a decent amount of time practicing blacksmithing.

 

Cheers Hunterbow, I'll give that a go.

[thingmaker3]

 The steel will need to be brought to a point slightly below the eutectic temperature (ie non-magnetic state) and then allowed to air cool

 

Well, sort of...

 

Eutectic and eutectoid are different, and niether applies here. The steel needs to be converted to austenite, which for pro-eutectoid steels is about 50F above nonmagentic.

 

Kurgan,

 

Sorry to hear about bad health. I hope you are able to resolve things and get better!