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Letter 12497
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Lee Gearhart |
David,
You'd get a better answer if you approached one of the faculty at a local University!
Mild steel = steel = iron ... where iron ore is heated up along with a goodly measure of coke along with, I believe some gypsum or lime to a eutectic melting point of 1050 degr. C ... eutectic meaning that if the right amount of concentrated iron ore is mixed with these ingredients, then the min. melting temperature in the blast furnace will be as above, ie. less BTU losses.
The resultant mix is iron ore or 'cast iron' but it is quite brittle. Ah, now to make it into steel, we have to reduce the phosphorus and sulphur content AND the carbon content... this is done by adding certain ingredients such as, I believe, aluminum to make the 'iron' more malleable somewhat, ie. to make it into steel. This is done normally in separate furnaces, often called open hearth furnaces, too.
In some steel foundries (mainly abroad)they use a very high phosphorous iron ore. And it was a Englishman by the name of Henry BESSEMER who in effect invented the Bessemer furnace, a large, snorting and spark generating cupola type furnace where the phosphorus generated much of the heat due to a so-called exothermic reaction. Again, this 'iron' has to be treated to make it more workable and not brittle.
Now after this is done ... voila, we have MILD STEEL !
For more boring info, go thou to any steel manufacturer!
I forgot! Usages! Every railway line is made of mild steel, your car or motor bike is made of mild steel, even some of your pots and pans are. The usages are legion! Ships, metal piping, bicycles, you name it!
I hope this helps the school project!
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Freeman Newton |
Mild steel is a carbon steel typically with a maximum of 0.25% Carbon and 0.4%-0.7% manganese, 0.1%-0.5% Silicon and some + traces of other elements such as phosphorous,it may also contain lead (free cutting mild steel) or sulphur (again free cutting steel called re-sulphurised mild steel) The stuff is used everywhere, looking out of my office window I can see diesel pump injector parts, loudspeaker pole pieces, Automated packing machinery parts and I haven't even got my glasses on. How its made and more info, depending upon the age of your son it's probably an idea he spends a Saturday morning at the local library researching his homework. Whilst the internet's good you still can't beat browsing through books at the library for homework.
Regards,
Richard Guise
- Lowestoft, U.K.
How wrong of Freeman Newton to state that "every railway line" is made of 'mild' steel. All 'curved' lines are made of Manganese Steel, mild steel would just not cope with side thrust of steering a train round a bend!
John P 
- Leics, UK.
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Thanks for the correction, John, but if you wish to be welcome here, please take care to avoid ad hominems like "How wrong of . . .". I thought Freeman did a nice job of offering the student some examples of products made of mild steel. Some of the components of the other examples he offered like cars, motorbikes, ships, piping, and bicycles are also alloy steel rather than mild steel. Thanks.
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Composition: Iron alloy with 0.3% carbon Properties: Malleable and
ductile, and therefore bends fairly easily Uses: nuts, bolts, screws,
tubes, girders
Methods of Identification:
Appearance: Bright drawn mild steel has a smooth, bright surface;
black mild steel is covered with a blue-grey oxide
Dropping: Gives out a ringing note Grinding: Gives off a shower of
long white sparks Effect of Heating: Slightly tougher but little
change
Mild steel is the most common form of steel as its price is
relatively low while it provides material properties that are
acceptable for many applications. Mild steel has a low carbon content
(up to 0.3%) and is therefore neither extremely brittle nor ductile.
It becomes malleable when heated, and so can be forged. It is also
often used where large amounts of steel need to be formed, for
example as structural steel.
Dominic C. Richards
- Minehead, Somerset, England
The simplest way of describing mild steel is a steel in everyday
use which will rust (ie. it is not stainless steel). Many people have
made reference to the carbon content of mild steel and unless you
know what this does then its pointless. Basically when manufacturing
steel carbon is added in varying amounts to alter the properties of
the steel.
A low carbon steel such as mild steel will be quite soft and
malleable so can be bent and forged into different shapes with
minimal heat treatment. Higher carbon steels (up to about 0.9%) can
be hardened using a method of heating and quenching (fast cooling in
oil or brine) to a point where they can be used for cutting other
steels, you would know high carbon steel as a drill bit or lathe
tool.
Hope this is helpful.
Scott Bartholomew
- Belfast, Northern Ireland
Hi, Scott. Thanks for the input, but I don't fully agree with it. Mild steel is low carbon steel, steel that is not hard and brittle, the stuff that plates and structural shapes are usually made of. A file will rust very quickly, but I would not consider a file to be made of mild steel -- but maybe when you said "everyday use" you were implying structural shapes as opposed to files.
Regards,
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 Ted Mooney finishing.com Brick, New Jersey |
June 16, 2008
G,day
I am after some information regarding Mild Steel.
I need to find out the difference between
Mild Steel - Grade 250 and
Mild Steel - Grade 350
The business has previously used the 250 Grade - 32 mm thick, as a
Low Temp Molten Lead Bath. Can I use the 350 Grade as I cannot get
the 250 anymore in large enough plate section.
Does it have any inclusions the 250 Grade does not have which will
shorten its lifespan? Or react with the molten lead?
Greg Cox
Engineer - Newcastle, NSW, Australia
June 28, 2008
I am doing a school research about those two steels. need to
compare their properties and range of uses.. but hard to find
relevant information..
can anyone help? or show me some useful website.
thanks..
Todd N
student - Sydney NSW Australia
Hi, folks. The Internet is a giant one-room schoolhouse, and unfortunately we have questions from engineers and elementary students homogenized into this one thread :-)
Greg might best be served with a reference to the ASM Metals Handbook, but that 20-volume (or so) set might leave Todd with no starting point at all :-)
Todd, I think what you might consider is that steel can be relatively soft (even though a soft steel is harder than a hard wood or hard plastic) or steel can be extremely hard and brittle, or anywhere in between. What hardness you want depends on the application.
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Consider a file. If it was softer than the metal you are filing, you'd just wear the teeth off and nothing more. A drill that is not harder than what you are drilling would just spin around until the point was gone. A soft hacksaw would be of no value either. But if you made buildings and bridges and cars of really hard steel, you wouldn't be able to file, drill, or cut them. Further, if you do much metalwork, you'll find that files and drills can break because they are very brittle. You wouldn't want to an apartment building where the I-beams were hardened steel and someone pounding on the ceiling with a broom handle because of a noisy upstairs neighbor would be at risk of shattering the beam and bringing the building down :-) Regards,
Thanks to all for your Inputs in enhancing my
knowledge... Anurag Ranotra
March 6, 2009 Mild Carbon Steel, is a steel which contains iron plus
small quantities of other elements i.e. 0.18-0.23%Carbon,
0.30-0.60%Manganese. 0.30%max.Silicon, 0.040%max.
Phosphorous and 0.50%max.Sulfur. Remus Serdena
April 15, 2009 Hello David abdul malik
May 22, 2009 Mild steel is the most common form of steel. Mild steel means - steel with less than 0.15% carbon low-carbon steel, soft-cast steel. Neither brittle nor ductile. This form is use in many applications due to low price material. Shah Khan |
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