Difference Between Pig iron, Wrought iron, Cast Iron And Steel - An Overview.

Iron in its purest state is available in the form of iron ore or ilmenite. It is the fourth most abundant element on the planet Earth.
This natural form undergoes different stages of extraction and production process, that results in pig iron, wrought iron, cast iron, and steel.
Most people refer to iron as steel, and steel as iron. Even if they look more or less the same, pig iron, wrought iron, cast iron, and steel, are different types of metals with composition of different components.
This video gives an overview of these metals and what differentiates them from each other.
#pigiron #wroughtiron #castiron #steel
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[@swingingvoter4309]

I did Materials Engineering as part of an Engineering degree many years ago. The video may be okay as far as it describes some commonly used terms, but it does not even remotely cover the topic of what iron and steel is. (Which is a huge topic, by the way, and I can no longer remember much of what I learnt.). Everything that people think is iron or steel is fundamentally a mix of Fe, a compound Fe3C. There will often be additional C and usually small amounts of other metals to give it required properties. Fe3C is a crucial component. Pure Fe (without any C whatsoever) is a substance that most people have never seen (I have only seen it once), is extremely difficult to produce, and can easily be cut with a knife, like sodium in your high school chemistry class. Also, you can’t discuss the topic without explaining Ferrite and Pearlite. Austenite (stainless steel) is also worth a mention.

[@MatthewETurner]

Almost right - wrought iron is not made from pig iron, and hasn't been commercially produced for around 100 years. It generally has about 3% slag content, distributed along the length of the piece if in bar form. The slag is there because the iron ore isn't liquefied when smelted. Instead, a spongy metal and slag "bloom" is removed from the furnace when cool, and then re-heated and compacted to remove slag and form a solid billet. My understanding is that pig iron and cast iron weren't produced until sometime in the late middle ages, when watermills were used to produce enough of a forced draft that temperatures could be reached to melt iron.Edited to add: My friends who are professional and amateur blacksmiths collect wrought iron because it isn't being made anymore. The best source I've seen was an old lineshaft - 2" diameter, 8' long and all wrought iron. Wooden wheel tires are another good source.

[@allangibson8494]

The Chinese were manufacturing cast iron products from about 800BC.

[@MatthewETurner]

Fifth century BC. en.wikipedia.org/wiki/Cast_iron 15th century AD for the West.@@allangibson8494

[@ericberman4193]

Finally, the correct definition of wrought iron!

[@alanalderson1427]

Another good example are Wrought iron columns in old Mills such as the huge columns at the Albert Dock in Liverpool.

[@allangibson8494]

@@alanalderson1427 The pillars in mills were almost always cast iron - the beams were however wrought iron. The current equivalent is “commercially pure iron” (99.97% iron) (UNS K00095 or UNS G10100).

[@lelandcarlson1668]

Would be nice to have a follow up video on the differences between gray cast iron, white cast iron, malleable iron and ductile iron. Thanks for a great video!

[@johnswarbrick2365]

Agree - this vid has underplayed the full role that cast iron has to offer - a total dis-service. especially when the micro-structure shown is for SG Iron and not "brittle" cast iron.

[@EdKolis]

Also different types of steel such as carbon steel and stainless steel!

[@jackzimmer6553]

Agreed. I worked for a few different gray iron foundries back in the ‘80’s. I forget what ductile iron is!

[@alanalderson1427]

Ductile iron is S.G iron or Spheroidal Graphite iron. It is strong and malleable. It is produced by treating ordinary grey iron in the molten state with magnesium or cesium which converts the flake graphite in grey iron to Nodular or SG iron.

[@pimpompoom93726]

Interesting. I worked in a cast iron foundry (mostly grey iron) when I was working my way through college and pig iron was one of the materials we used to develop the 'charge' for the cast iron arc furnaces. As I recall, we also used coke and steel stamping scrap in building the charge. But I always assumed the pig was essentially pure iron, not the same as wrought iron (which contains a lot of silica slag). I learned something new today!

[@kevinfernandez9999]

10 years ago i used to work in a foundry, i worked with pig iron and all other forms of iron. It was the best job i ever had.Brought back so much memories ❤

[@bbax069]

As a metallurgical Engineer, you got the basics spot on 💯

[@angrymandalorian8496]

Thanks, Master Blacksmith here. Next time someone asks me this I’m gonna point them to this video. Easy for everyone to understand. You even threw in history on some of the terms 😊

[@richmorin424]

The video content is very informative and nicely done. The presenter also speaks clearly and at a good pace. However, I found the grammatical errors (both spoken and in the captioning) to be quite distracting.

[@NickfromNLondon]

Pedantry corner 1 The last Bessemer Converters in the UK have closed, only electrical furnaces are now used. 2 The sample undergoing tensile testing in the section on cast iron exhibits necking so is too ductile for cast iron. 2 The property of steel is ductility being its ability to deform plastically before rupture. Steel is elastic up to the yield point then undergoes plastic deformation.

[@kevfrombutterley]

1. *and blast furnaces

[@briannewton3535]

Like yourself I am a pedant. I note that your three points are numbered 1, 2, and 2. It was a shame that 3 never made a showing 😊 Maybe another edit?

[@stevec8861]

Should have included ductile iron category too

[@thepagan5432]

We made large gearboxes from cast iron, however we had asome that would crack and be returned. We investigated the failures and although there was a design flaw that could contribute to the failure we changed to SG iron and rectified the small design flaw. We had better machinability and no more cracked gearbox cases. Thanks for the post, quite interesting.

[@Bird_Dog00]

What is SG iron? And by cast iron, do you mean grey iron or some other alloy?

[@thepagan5432]

@@Bird_Dog00 SG iron is a refined spheroidal grafite iron, also called ductile iron. It coped so much better with the forces that the gearbox was subject to. It was rotating 3 tonnes at a radial distance of 1 metre. However, the gearboxes were subject to abuse by operators that did not understand up from down, 😂. The original gearbox was made from grey iron.

[@Bird_Dog00]

@@thepagan5432 Ah another term for ductile iron. Good stuff. You can cast it like grey iron and if you treat it right, you get mechanical properties almost like steel... Never got to work with it. Did machine grey iron though. And yea, as someone working in maintenance in the industry, I get the issue with unskilled operators. A lot...

[@37adrianporter]

Wrought is produced by drawing in and out of a puddling furnace ! To obtain long carbon strings.

[@DanielCunningham_Gia-na-dai]

You might have added the melting points of wrought iron and cast iron and steel and the relative, respective tensile strength. A comparison of wrought iron with bronze for the same properties would be interesting

[@babaoreally8220]

In addition,pancakes provide unmatched eye protection from spatter when you are below the weld area.You can carve or file the balsa wood eye frame to perfectly fit your forehead and nose contour so that nothing gets in.I still use a 50yo pancake,handed down from my dear departed Dad for garage work.He began his pipeline career in the early ‘50s,often took me to work with him in the summer.I just loved those rural pipeline right- of - ways,quite an adventure.

[@albertbell7120]

Love the pancake🇬🇧

[@davealexander9983]

Ilmenite does contain iron, but it is a primary ore of titanium . It is not used as an iron ore.

[@whereswaldo5740]

Yeah. It goes from steel to stainless steel with some minor chemical additives. And then titanium. Ever work with inconel or monel? Interesting stuff. Kinda gooey like stainless to machine. But crazy oxidation resistance under extreme conditions of salt heat and other chemicals. And when machined leaves a beautiful rainbow effect in the metal. Very odd substance.

[@alyoshakaramazov8469]

I think he meant limonite?

[@clarkelliott5389]

Perhaps he meant hematite, Fe2O3.

[@keithjurena9319]

Cast iron comes in many types. Malleable and nodular cast iron are not brittle yet have very good casting qualities like fluidity. The excess carbon common to all cast irons lowers the melting temperature and increases fluidity.

[@pimpompoom93726]

Indeed, they could have discussed the various cast irons-malleable, nodular (ductile) and grey iron. All with different properties.

[@someguy7805]

Nah, cast iron is used if you break a bone, and then run out of plaster casts.

[@AquaMarine1000]

Carbon is not an alloying element. For an alloy to exist, the combination of at least two metals in chemical solution is required. One common missbelief is the metal brass. The two metals copper and zinc that make brass are not in solution. Thus, it must be a conglomerate forming fine crystals of each metal. For carbon to make steel, it must be in solution. The perfect solution of carbon in steel is 0.83%. This structure is called perlite, mild steel. At 1.0%, carbon steel can be heat treated hardened and tempered as tool steel. This structure is a mixture of perlite and iron carbide. The carbides form an austinatinic structure after heat treatment, but this is not an alloy. Alloy steels must contain more than one metal in chemical solutions. Examples are stainless steels and alloy tool steels. Metallurgy is the understanding of chemistry, molecular structures and crystallography.

[@allangibson8494]

Carbon does alloy with iron. The upper limit is about 0.8% without adding other elements otherwise it precipitates out of solution on cooling.

[@flamingfrancis]

The VAST majority of steels made for today's usage contain

[@ludditeneaderthal]

40 points is the floor of heat treating straight carbon steels, not 1%. Spring steel (unquestionably heat treated) typically contains 60 to 80 points of carbon. The infamous Mauser 98 rifle has receivers originally made from a very plain 1040 low Sulphur steel. Tool steel is heat treatable, but not all heat treatable steel is tool steel.

[@AquaMarine1000]

@ludditeneaderthal Exactly what was said. The most common heat treatable plain carbon steel would be silver steel ground round stock and gauge plate flat ground stock.

[@allangibson8494]

@@ludditeneaderthal And not all guns need to be particularly strong… The WW1 Spanish Ruby pistols were rather notorious for being made out of steel tending more towards unalloyed iron.

[@bradyt7857]

Robot narrator speak English very goodly!

[@deedoyle4069]

Excellent video! If you do more videos, PLEASE get your script EDITED for Accuracy in the use of the American-English language. Thanks!

[@deedoyle4069]

--US English has nuances, that if ignored, lend to misinterpretation.

[@dominicestebanrice7460]

Really helpful. Thanks! I now see the path from ore to pig and then the split to either wrought or cast iron OR onto the steel route. A follow-up video on the low carbon/mild steel versus high carbon steel versus alloy steel versus stainless steel would be really appreciated. Also, the ancient iron from a "bloomery" never actually melted, right? It was actually the silicate/rock/slag that melted leaving the softened iron lump behind as I understand? Ancient/Medieval iron is therefore different from pig or cast or wrought iron, yes?

[@redwolf92]

what about *Big Iron* ?

[@Foxeyify]

Fun fact: a metal and a gas are technically types of ceramic, not alloys. See tungsten carbide or the topic 'ceramic composition and properties' in Encyclopaedia Britannica. I'm not an expert in these things so maybe there is more to this but my understanding is that an alloy is a combination of metals not a metal and a gas. Having said that, I'm sure many gases will make their way in no matter what so, like with virtually everything, the facts are probably more nuanced than that.

[@johnswarbrick2365]

The description of cast iron as being "brittle" is correct but when converted into SG or Nodular iron it can be twisted/bent and in most applications is stronger than steel. The microstructure shown is inaccurate as it is for a ferritic SG or Nodular Iron showing spheroids of free carbon that act as "stress sinks" when subjected to load, whereas a cast iron has the free graphite in flakes which form a fracture route when sdubjected to loads. When tensile strength levels for the different grades or tensile strengths of SG Iron are compared with similar tensile strengths of steel SG Iron is far superior as its yield strength is significantly higher, and it is at the yield point that failure occurs. Not at the tensile strength level. The only weakness of SG Iron against steel is its weldability and use in construction, although a fully ferritic SG Iron can be welded.

[@uncralph4354]

Thanks, I learned this in HS but after 45 years I needed a refresher course!

[@alexlindekugel8727]

wrought iron is not that wrought iron is maid with the bloomery prosses that mixes slag and iron in a semi molten lump. that is then worked with a hammer to mix the slag evenly into the iron. no steel never evor contains copper! is copper sits at iron boundary's and would cause it to fail with very little force.

[@jamesfahey4508]

Conservative Australian Prime Minister Robert Menzies sold pig iron to Japan prior to WWII. When that pig iron came back as bombs, he received the contemptuous nickname of Pig Iron Bob.

[@pcka12]

Hmmm. What about the puddling furnace in the original production of wrought-iron from pig iron?

[@teukel1157]

Thank you. Learned interesting distinctions and cleared up some terms thrown around.

[@LouisEmery]

Now I'm all set.

[@lorisperfetto6021]

This is the answer to a life long question

[@user-ie3fl1uy7v]

I worked at a steel mill back in the 70 and early 80 , steel has many grades depending on the buyers need, even poored stainless yes l was a molten steel pourer

[@leorbuis9024]

Good content and you have the right idea but you'll get far more subscribers if you ditch the computer narration.

[@JohnAshworth2023]

And proofread and correct the grammar of the accompanying text!

[@janeblogs324]

Do you want him narrating in Indian?

[@kegginstructure]

Given the word usage, that narration has to have been translated from some central or east Asian language. So it is not only the fact of computer narration, but the text gives it away as a non-western source.

[@rameshhariharan2623]

Yes we all know carbon is not alloying element, but u must kn9w without carbon u cant do anything. So wt u say be in d8fferent ways but essence is not essence it is an effect of property changing by chemical reaction process. It is like our stomach digestion

[@BCarli1395]

Thank you. Very informative.

[@Ukepa]

good clarification of terms we've used without really knowing what they mean

[@ChrisCraigie-oi1un]

Great presentation! I learned a lot. Thanks.

[@DrWoodyII]

Good information, thank you for sharing.

[@alanalderson1427]

Not all Wrought iron is worked. The columns at Albert Dock in Liverpool are actually wrought iron. I have checked the microstructure whilst at BCIRA before complete restoration in the 80's.

[@user-td6wy7xe8s]

What is the "coke" he refers to???

[@boblordylordyhowie]

I heard something a while back, tell me if I am wrong, but blacksmiths would treat blades by rubbing the hot metal through deerskin, to do something to it. If I remember correctly it was an early form of carbon steel or similar?

[@fyrman9092]

Excellent science lesson!

[@lalva5798]

Quite informative, thank you

[@flamingfrancis]

What is not explained very well here is the primary use of Iron from a blast furnace being transferred in the molten state from the BF in special torpedo cars through to the steelmaking plant, usually Basic Oxygen Steelmaking plant. In my long experience in steelmaking in an integrated plant, Pig Iron was no longer made but when it was it was used in the foundry.

[@nathanielstanford3115]

Iron in the 4th most abundant element in the Earth's crust. When considering the entire planet, it is the most abundant element.

[@Theotherlostprimarch]

Hats off to the welder in the pic who said to hell with grinding the paint!

[@tombinkley2688]

Puddling process makes wrought iron. Cast iron is easily differentiated from steel by the form carbon takes. IE., in cast iron carbon is in the form of free graphite whereas in steel carbon is chemically combined with iron in the form of iron carbide Fe3C.

[@stephensarkany3577]

There is a limit to how much carbon can form compounds with iron , any extra will be in the form of iron glakes like grey iron or spheres like ductile iron.

[@thedolphin5428]

Lmao at all the comments below all arguing the finer points of metallurgy and criticising a 5 minute YT beginners video on the very basics of iron and steel. Q. How many metallurgists does it take to change a light bulb? A. That depends on exactly what percentage of carbon was used in the forging of the ladder being used to reach it. Lol.

[@blackangel618]

Nice video thank u

[@CilVine]

Thanks for the knowledge.

[@bohdanburban5069]

Short & sweet !

[@mannymorales7913]

Thanks for producing and sharing this great information!

[@terrysanders2817]

Well presented!

[@richardkut3976]

Excellent, thanks.

[@davidg5369]

How is ductile iron made? Is it different from cast iron? Also, how is stainless steel made?

[@bapi6643]

What about ductile iron ?

[@number1genoa]

SG or Spherical Graphite cast iron is not brittle like common Cast iron

[@robertthomas3777]

Interesting. How do you make iron plate?

[@Bird_Dog00]

Depends on context. In Satisfactory, you simply run a conveyor belt from your smelter to a constructor and select the correct recipie. IRL the process is a bit more involved... Take a suitable iron-based alloy, heat it and roll it into the desired thicknes. Then cut it to size. depending on thicknes and use, you can also emboss it with a pattern.

[@joelperillotempra9324]

If you want a Quality made steel from the furnace try this wrought iron alloying in the cast iron may 65% wrought iron and 35% cast iron is a total of alloy steel

[@bsdiceman]

Good video

[@shdwbnndbyyt]

There is also extremely pure iron 99.99% pure that has been found in a tool found embedded in coal when the coal seam was mined. How the tool was embedded in the coal seam, no one knows. There is also wootz steel, made in India, called Damascus steel because that is where the items made from it were marketed from.

[@Andrew-pm5bg]

Great video.

[@theapple3160]

nice good job

[@robertswartz3418]

I have an 1850 Colt firearm made with Sheffield Steel. EDX (EDS) shows iron, silicon, carbon, phosphorous, and oxygen, but not manganese. I understand that there was a trade-off between carbon and manganese. Too much carbon and it's not workable. Too much manganese and it's brittle. I'm assuming that the 1850 arm was made with cast steel. But after Bessemer all steel using spielegeisen (or whatever) had both carbon and manganese. But that was 1858 and Bessemer had air pockets which made it unsound for firearms. So, maybe even after Bessemer they continued to make cast steel until Sir Whitworth solved the problem of air pockets in 1874.

[@flamingfrancis]

Steels from the yesteryear era noted were nowhere near the purity / grain structure of steels of the past 5-6 decades. We have seen the development and use of techniques such as vacuum degassing, controlled Argon stirring which have improved the cleanliness of steels. Steels made using continuous casting have also improved over the former ingot route steels. Every steel I am familiar with has a Carbon and Manganese specification along with specific alloys for spring steel, rail steels, pipeline steels, gas platform steels, stainless steels, to name some. Have seen virtually pure Fe where C was

[@robertswartz3418]

@@flamingfrancis my thought is that after Bessemer proved the importance of manganese, the Sheffield folks got on board. The process of using the spieg was covered by patent, but I bet they blew that off. That was a tough patent to protect. Mn appears in earlier guns, but it seems it just happened to be in the ore. After Bessemer though it was purposefully put in the ore, up to 10-15%. A big benefit of Mn was to knock out sulfur which contributed to a brittle product. But what do I know? I'm a lawyer.

[@robertswartz3418]

Not in the ore, as I said, but in the crucible with the fe.

[@chadcurtiss5965]

Pig iron is also a structural building material for large buildings… in China…. 😬

[@Paulftate]

new subscriber 👍

[@johndufford5561]

This is exceedingly good overview. Thank you.

[@00kt86]

I have wondered what pig iron was. Now I know.

[@markhorton8578]

Very Good video, music could have been better.

[@chuckaddison5134]

I seem to recall that Pig Iron was iron with a carbon content of about 4%

[@allangibson8494]

Pig iron is the cast iron straight out of a blast furnace.

[@flamingfrancis]

@@allangibson8494 Indeed I found that confusing also. Going back five decades we called the BF molten Iron Cast Iron but older operators referred to Foundry remelted Pigs that were cast as the Cast Iron....Carbon around 2-2.5%. BF Iron (4-4.6% C), was transported to a Pig Mill located near the Foundry where it was stored and used as required. Australia had a famoud WW2 Prime Minister named Pig Iron Bob (Menzies) so named for his decision to transport Pig Iron by ship to the enemy, Japan.

[@spudsdavenport]

What about taconite? Iron ore was mined out of northern Minnesota, and shipped to the steel mills as taconite pellets. How does is differ from pig iron?

[@realkanavdhawan]

Ilmenite is an ore of Titanium

[@will5286]

Pretty damn basic-I had hoped for more.

[@MrGaborseres]

Cool 😎 👍

[@OceanusHelios]

Most people consider iron and steel to be the same. Most people in China that is. This must be a video made to educate Chinese people. The rest of us have distinguished iron from steel since the iron age began.

[@P_RO_]

Isn't just them that need 'educating' on the difference. You read and hear a lot about 'iron roofing' and it's all mild steel sheet...

[@irafair3015]

People everywhere get it mixed up.

[@johngriswold]

Wow. Their near illiteracy neatly disguises their inability to research and present the material.

[@mexicanwitharock]

I don't know what the fuck I'm gonna use this knowledge for but meh I'm gonna fucking learn it.

[@aniksamiurrahman6365]

OK. Then what about stainless steel? I guess an episode about different type of steel is due now.

[@Simon_Jakle__almost_real_name]

Interesting, but haven't we surpassed the decades when we used steel that wasn't stainless? I would say/write since about the 1960ies hardly anyone uses steel that easily corrodes, any builder will afford stainless or inox (or whatever naming) steel, so why isn't that part of the video? would "we" drown back into the 1950ies or to even before? why would we? I'd even add it wouldn't be simple finding steel that rusts normally (due to abundance of chromium or whatever alloy component). At least that's still the situation in "metric" europe, i'd say.

[@belzebubukas]

Damn, didn't realise they had coca cola in the iron ages

[@timmckee2813]

damned chemistry...every where...thank...

[@khushipingulkar8084]

Plz guys like this video and bring smile on creators face

[@TonySopeano46]

Mao: Just melt it all together 🤷🏻

[@Narsuitus]

What kind of metal is used in gun barrels, knives, and swords?

[@Uncle_Matt_]

High carbon steel

[@allangibson8494]

@@Uncle_Matt_medium carbon steel - high carbon steel is too brittle (think chisels). Guns have also been made from pretty much any metal you can imagine that was available in a given time period (and the odd one made of wood). Straight iron is included in that list (right into WW1).

[@robertparkinson2102]

Early cannon were made by heating rods of iron and hitting them with a hammer until they looked like they were joined together. They often blew up killing the soldiers. When a liquid slowly turns to a solid impurities are pushed into the remaining liquid (bubbles are in the middle of an ice cube). Solid cast iron cylinders were made by John Iron Mad Wilkinson, a contemporary of James Watt, in Bersham nr Wrexham. By rotating the cylinder and boring out the middle he made cylinders for the industrial revolution possible and cannon that killed more of the enemy. He sold cannon to both sides of one war. Bersham iron works is so historically important that its sign cannot be big and it is often missed.

[@user-cm4us3hy7y]

4140 or ordinance steel.

[@ludditeneaderthal]

Depends on the barrel, knife, or sword. Pretty much any ferrous metal from cast iron forgings, to meteoric iron, to high alloy steel, to anything in between, as well as forge-welded laminations of multiple types. Depends on era, locale, and manufacturer, as well as how that knife, sword, or barrel would be used, and the price-point it would be sold at.

[@NoEgg4u]

@0:23 "It's the 4th most abundant elements on the planet." What are the other 3?

[@irafair3015]

Google it.

[@rm3141593]

According to Google: Oxygen at 46%, Silicon at 28%, Aluminum 8%, and iron at about 5.6%.

[@davidthompson6636]

…And Bog Iron! Uses a bio-chemical process to ‘form’ .

[@NoahSpurrier]

Malleable and ductile iron.

[@geoffgeoff143]

Iron ore isnt pure iron. Pure iron does not exist naturally on Earth except in very very small amounts.

[@keirfarnum6811]

Steel is just iron with “stalinium,” from the blood of Joseph Stalin, in it to make it harder. 😂

[@UrsaJeager]

COKE ? ! ?

[@DBT1007]

Pig iron = iron ingot. It's easy word.

[@argentum530]

Hopefully you can get a better translator and copy editor to correct the many grammatical and spelling errors.

[@clpfox470]

I fooled you, i have pig iron. All pig iron

[@cicero5451]

Excellent comunicator

[@huntclanhunt9697]

I prefer L e a d

[@thecamocampaindude5167]

Iron is iron

[@Hippucytees]

I thought it was because it was a pig to work with.

[@JohnJohansen2]

Why is the last few minutes disturbed by visual recommendations??? It WERY annoying!

[@irafair3015]

There's an app to get rid of them. Unfortunately, I don't remember what it is called. However, it runs on my computer so I never see those recommendations.

[@s1lv3rbordeaux47]

So from rock found to pig iron, where did that knowledge emerge from? A light bulb moment for an ancient human? Don't see any monkeys doing anything even close though do we?? Every bit of history might as well be considered a lie or falsification..............

[@P_RO_]

Probably got started when they fond something odd in the ashes or a fire then found out how to reproduce the event. Without metals only primitive lifestyles are possible- it was 'the iron age' which gave us the means to better our world significantly.

[@hazeentertainmenthiphop]

Meh..

[@jarrodyuki7081]

pig iron cast iron wrought iron and steel!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!