From the way it rusts and breaks

[kogatana]

I have found a source of what I believe is iron, now what kind of iron, I would need your help.
Can we have an idea of the iron (or more generally the steel) by looking at the way it rusts: is there any particular rusting pattern for a given iron/steel?
Now if we break the piece, by repeated back and forth movements, and observe the fracture, I'm sure we can tell something about the iron/steel. Not a precise metalurgical analysis sure, but maybe a rough idea of the metal, and how it would look like when etched for example Recently I watched a show about an archeological metalurgist who uses a microscope to identify the crystaline structure of an iron/steel and then date it.

Here are 2 pictures. One shows the rust, with pits as deep as about 1/16" or 2mm. The other is a close up on the break, and the sawn area.

Is this what one call wrought iron? I think I can say no, I've seen broken wrought iron and it looked more fibrous than this.

Ludo

[Woody]

Ludo:

What was the original use of this material, was it a spring etc? If you know that, you can consult junkyard steel lists and or Machinery's Handbook and get some idea of the type of alloy. You can heat a piece of it to non magnetic and then quench in oil. After it is quenched try cutting the quenched area with a file. If the file skates, it's high carbon, if the file will cut it, reheat it to non magnetic and quench in water try the file again. If a file will cut it at this point, it is mild steel. You can also heat to non magnetic quench in oil and then try to bend the quenched area, if it bends, mild steel, if it breaks, high carbon steel. You can also spark test it and there are those who swear by spark testing, but I find it to be not much use. As for what if any alloy mateial is in the steel, that's anybodies guess unless you can determine the original use of the steel.

Before half the blacksmith world goes of on me with a rant about the advantages and the preciseness of spark testing, save your effort, I don't care.

[ThomasPowers]

It does not look like wrought iron---not fiberous enough. WI tends not to pit as deeply as mild steel for a given time and conditions and when it rusts you can generally see lineations in the rust pitting not random pits.

Thomas

[evfreek]

Hi Kogatana. I believe that your question is: is this piece wrought iron? Not: "what are the key alloy ingredients in this steel?"

If it is the first, I saw a really interesting demo given by Phil Baldwin. It was kind of primitive (in a metalworking sense, not in a quality sense). No spark testing!!!!!!! He was working with two metals. One was wrought iron from a shipwreck, and the other was blister steel, both classic stocks of the old time blacksmith. First, he broke off the end of the wrought iron bar. Very obvious fibers were visible curving toward the break. Then, he heated and quenched both. The scale flew off the steel, leaving bright spots. The difference was *very* obvious. The demo was long (it stretched almost 3 days) but much attention was paid by the audience.

As for your photo, it does not look like wrought iron to me. It looks like mild steel. There are experts here who know much better than I how to interpret the first photo. Oh, and of course, you could try a spark test .

You also referred to etching and doing a metallurgical analysis. This is possible, but challenging. You will need to anneal and polish the sample, then etch with nital and observe under a special microscope. The magnification is not critical. 100-200X is sufficient, but lighting must come from above the subject. It may be possible to modify a hobbyist or inexpensive childrens microscope for this task. If you have any success at this, please post back as to your findings.

[ThomasPowers]

From "Formulas for Profit", Bennett, copyright 1939, 4th printing

"To identify iron from steel"
"Mix 5 drops nitric acid with 10 drops H2O", (remember acid into water *NEVER* water into acid),"File a clean spot and place a drop on it.

If it is steel it will turn black immediatly. If it is wrought iron or malleable iron it will stay bright for a considerable length of time."

Use at your own risk!

[kogatana]

Woody, the piece come from an old fence, used now to build a shelter for chickens. According to my stepfather who owns both the chickens and the fence, it is some 20years old. I will try to do something out of that bar.
Thomas and evfreek, you seem to confirm my first idea that it is not wrough iron indeed. evfreek, I like the idea of observing the crystals of the metal following the hints you provide, in Japan there is a quaterly about woodworking and tools that regularly shows pictures of various steels' crystalin structure used for toolmaking. Pictures are taken with just a simple optical microscope.

By the way, what should I do with the rust? Put it as is in the forge's fire after some rough cleaning with a wire brush?

Ludo

[kogatana]

Thomas,

I'll try that. Let me find some nitric acid... I'll keep you all updated.

Ludo

[bruce wilcock]

i use quite a lot of wrought iron re worked chain and anchors , if its a small section say 1+1/2 ins nick it deep on both sides with a chisel then smack it over the edge of your anvil or prop it against the anvil foot and hit it with a hammer and if wrought iron it will break clean with a large grainy laired break , when we made horse shoes out of wrought iton all the iron was nicked with a cold sett and then broken over the anvil,the ease that wrought iron snaps when the grain has been broken even big sections is one of the most dificult to avoid and has no comparison to working steel , to work iron used for replacing, load bearing ,or stressed moving parts ,needs a direrent skill than steel

[Woody]

Ludo: My guess is mild steel

[ThomasPowers]

20 years is not *old* the change over from wrought iron to mild steel was going on in the 1880's and 1890's acording to "Practical Blacksmithing". Most use of it died out in the 1930's with a few restricted uses carrying on---I know some bridges that used WI along the ocean in the 1950's.

Unless it had been an older piece re-used it would not be WI. And a lot of old WI went into the steel refineries of WWII making it harder to find in certain areas.

My youngest datable stock (that I didn't smelt myself) was installed in 1929; my most recent find was installed in 1906.

Thomas

[bruce wilcock]

wrought iron was made later in the uk Thomas Walmsley caried on untill 1975 at the Atlas forge Bolton, i served my time not far away in Burnley ,and we went to colect iron as we needed it ,the last 6 months or so they stopped puddeling and were rolling out iron waggon axels from the railway coal waggons , the following year i left yorkshire and moved to the shetland isles ,i was so interested in the iron process i spent some time trying to find a way get hold of some of the plant to continue iron working ,but at that time iron was finished and no one was interested most went to scrap ,but later salvaged and taken to Ironbridge to form the center of the iron working museum ,where they use the rolls to demonstrate ,they made a puddeling furnace that wasnt a sucsess the arch looked too flat to me to drive the heat down ,so they never managed to make a great sucsess of puddeling ,a pitty .

[kogatana]

Woody, does mild steel only bend without breaking when repeatedly bent? On the picture of my first post of this thread, you see a 1mm deep saw mark: without first sawing the bar, it would not break after 5 solid minutes of repeated bending.
To make sure of the metal, I'll try the quenching and file method.

Thomas, yes, 20 years is not old. And I also tend to think that what I've got is the result of a mix of various irons and steels.

Bruce, I've just noticed you are from the UK. Here is a picture of wrought iron bars (that I'm sure it is WI), from a bridge made in the 19th century in Japan, from british iron. The picture was taken in the shop of a plane blade maker in Miki-city Japan. Steel and iron from England is widely used by Japanese woodworking tool makers. Also, an anchor and the chain, from unknown origin, also wrought iron and from another Japanese toolmaker.

[ThomasPowers]

Bruce I was at the Blists Hill Museum when they were siting in the old steam shingling hammers.

The Real Wrought Iron Co, LTD sells "remanufactured" wrought iron from that plant/museum and has a website. Note that it's a tad expensive compared to finding and recycling the stuff locally yourself.

I have also smelted WI from ore but it's more of an interesting tidbit rather than a practical means of supply.

[kogatana]

Thomas, interesting!
I'd be interested to know where you got your iron ore and to read you if you have posted your experiences with the smelting.

Could you post a link to the company's web you mention?

[ThomasPowers]

Ores I have been a party to smelting include:

Taconite pellets, commercially processed for steel mills, "mined" from the RR tracks where the loads spilled on a curve/bump, nasty stuff to work with as they have to be crushed and are pre-fluxed for a blast furnace; so are way too fluxed for a bloomery---"iron soup" was the result and hard to consolidate the bloom.

Goethite from an American Civil War iron mine abandoned after the war was over. A nice polite earthy ore; good bloom

Magnetite: from two sources the first was a fellow who drug a magnet along a lake shore to pick up the "iron sand"; the second was buying it from a pollution control supply company which sold it cheap---shipping cost more.
Nicest stuff we have used; great blooms.

Somewhere on the net is a humorous account of us building and smelting iron using year 1000 nothern european technology. I'll have to search for it.

As for the Real Wrought Iron Company LTD, google it!