Iron+and+Steel

=**IRON**= Type: Cast iron Ingredients: Iron with lots of carbon Strengths: Molds to any shape, strong in compression Weaknesses: Weaker than steel in tension, breaks without warning Arch bridges, cannons, historic domes Example: Iron Bridge - Shropshire, England It wasn't easy for you to squeeze this cast-iron block. Cast iron is strong in compression. That's why early arch bridges were made of cast iron. It was easy for you to pull this cast-iron block apart. That's because cast iron is brittle -- it snaps without warning.
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It's lightweight and easily transported. It was and still is widely used especially in rural and military buildings such as sheds and water tanks. Its unique properties were used in the development of countries like Australia from the 1840s, and it is still helping developing countries today. CGI was invented in the 1820s in Britain by Henry Palmer, architect and engineer to the London Dock Company. It was originally made (as the name suggests) from wrought iron. It proved to be light, strong, corrosion-resistant, and easily transported, and particularly lent itself to prefabricated structures and improvisation by semi-skilled workers. Today the corrugation process is carried out using the process of "Roll Forming". This modern process is highly automated to achieve high productivity and low costs associated with labor. In the corrugation process sheet metal is pulled off of huge rolls and through rolling dies that form the corrugation. After the sheet metal passes through the rollers it is automatically sheared off at a desired length. The standard shape of corrugated material is the round wavy style, but can be easily modified to a variety of shapes and sizes by simply changing the dies.
 * [[image:MountLawleyRooftops_gobeirne.jpg width="398" height="268" align="right"]]Corrugated galvanized iron** is a building material composed of sheets of hot-dip galvanised mild steel, cold-rolled to produce a linear corrugated pattern in them. The corrugations increase the bending strength of the sheet in the direction parallel to the corrugations, but not across them. Normally each sheet is manufactured longest in its strong direction.

** Requirements to be an ironworker **

 * Minimum age of 18 years.
 * High school diploma, G.E.D., or equivalent as specified by the local training committee.
 * Good physical condition - The materials used for ironworking are heavy and bulky so above average physical strength is necessary.
 * Agility and a good sense of balance are also required.
 * Drug and alcohol free.
 * Must meet requirements as set out in applicable citizenship laws.

=**STEEL**= Type: High-strength steel Ingredients: Iron with a touch of carbon Strengths: One of strongest materials used in construction, strong in compression and tension Weaknesses: Rusts, loses strength in extremely high temperatures Cables in suspension bridges, trusses, beams and columns in skyscrapers, roller coasters Example: Sears Tower - Chicago, Illinois You had to push extra hard on this steel block to make it bend and break. Steel is stronger than any other material in compression. That's why engineers choose steel beams and columns to support most skyscrapers. You had to pull this block incredibly hard to make it break because steel is stronger than any other material in tension. That's why the cables in the Golden Gate Bridge are made of steel.
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“//the old cast iron buildings died out. I'm not really sure whether the new skyscrapers killed them, or the new esthetics//”

I think that old cast iron buildings died out but the skyscrapers and new esthetics are not responsible about that. The technology makes us evolve, so the new techniques, improvements and the development bring us new ways of constructions. Welding, alloys and steel change the world of materials forever.

=Chat Log about Iron and Steel= Katherine Fernandez: hello Angela! Angela Herrera: hello Katherine! Adarenis Garcia: hi girls! Angela Herrera: hello ada! Katherine Fernandez: hey! did you read the text about Iron and Steel? Adarenis Garcia: yes I do!!! Angela Herrera: yes, it's interesting, what do you think about it? Adarenis Garcia: It’s very interesting!!! Katherine Fernandez: yes it’s interesting ...but I think that iron and steel has more advantages than wood or stone don’t you think? Adarenis Garcia: I agree with you Katherine!! Angela Herrera: yes, the iron and steel provide far stronger and taller structures with less expenditure of material than stone, brick, or wood. Adarenis Garcia: yes, and the iron and steel allow create buildings more versatile. Katherine Fernandez: that’s right and is weather resistant too... for that is use in skyscrapers Adarenis Garcia: yes and also are used to construct bridges!!! Katherine Fernandez: almost all of the skyscrapers are made of iron and steel… that’s probably happens in the 20 century when this material star it popularity... and of course the bridges specially the ones that hanging Angela Herrera: it's very useful in construction, but I didn't know that the cast iron was the first metal that could be substituted for traditional structural materials, so it's a popular material since the 20th century Adarenis Garcia: yes, and it’s possible to create buildings much more solid, stable and durable... Katherine Fernandez: yes that right and after that is still using nowadays...but it also has some disadvantages like for example iron has much more compressive than tensile strength. Angela Herrera: but it was replaced by steel which is more uniformly strong, elastic, and workable, and its high resistance in all stresses can be closely calculated. Adarenis Garcia: yes the steel is resistance to compression and also tension!! Angela Herrera: the only disadvantage is the labor, but in the 20th century Steel Structural Members developed the welding, so actually it's posible to produced fused joints with less labor and material. Katherine Fernandez: umm that’s great... but can you tell me what is welding? Adarenis Garcia: other disadvantage is that steel need be protected against corrosion!! Of course, the welding is the process developed in the 20th century to unite the steel beams! Katherine Fernandez: umm ok thanks ada...and that is important because that was the solution for the problem of the iron and other advantage it’s that you can do a lot of forms with these materials. Angela Herrera: oh yes, steel structural members are rolled in a variety of shapes, the commonest of which are plates, angles, I beams, and U-shaped channels, among others, it's very malleable. Adarenis Garcia: yes I am agree with you… and together with the welding is a very strong material that allows you to create strong structures!! Do you know what is it welding importance? Katherine Fernandez: well, this is a fundamental change in architectural technique, the effect of which cannot yet be estimated. Angela Herrera: normally, steel must be protected against corrosion by surface covering, but alloys such as stainless steel have developed for exposed surfaces Katherine Fernandez: and do you think that are aluminum and stainless steel heavy metal alloys? Adarenis Garcia: well, I think that these heavies are very wonderful because resolve the problem of steel corrosion, and also make more resistant the steel beams… Angela Herrera: cool! More advantages about these materials! Well girls, I have to go… See you later! Adarenis Garcia: see you later! Katherine Fernandez: I have to go too, take care!