Iron+and+Steel

What are the advantages of iron and steel over stone and brick?
===The iron is a material much stronger than wood and stone and it can produce more spaces. ===

What is the importance of steel and iron after the 20th. Century
=== The evolution of steel frame construction in the 20 th century entirely changed the concept of the wall and the support. Quickly the iron encouraged architectural adaptations, first as columns and arches and afterward in skeletal structures. ===

What are the characteristics of steel?
===The iron have abilities to bear loads and to be produced in an endless variety of forms, in addition it have resistance to fire and corrosion. ===

What are the disadvantages of steel and what solutions have been found?
===Normally, steel must be protected against corrosion by surface covering, but alloys such as stainless steel have developed for exposed surfaces. ===

What is welding? What is its importance?
===Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. Welding is what holds the majority of structures together-bridges, cars, tractors, cranes, buildings, etc. ===

What shapes are formed with steel?
===Steel structural members are rolled in a variety of shapes, the commonest of which are plates, angles, I beams, and U-shaped channels. ===