Steel Products & Forging Industrial Technology Books
Industrial Projects on Rolling Mill, Billets, Steel Wire, Galvanized Sheet, Forging and Castings.
In general, galvanized sheet metal is mild (carbon) steel that is used for a ton of different things. This material is tough and strong, and it can be fairly easily worked (bent or formed) in a number of different ways to produce useful products (like HVAC ductwork, to name just one application). It lasts a long time, too, because the zinc coating (the galvanizing) inhibits corrosion quite well.
Forging or cold forming are metalforming processes. There is no melting and consequent solidification involved. Plastic deformation produces an increase in the number of dislocations resulting in a higher state of internal stress. Indeed, strain hardening is attributed to the interaction of dislocations with other dislocations and other barriers (such as grain boundaries). Simultaneously, the shape of primary crystals (dendrites) changes after plastic working of the metal. Dendrites are stretched in the direction of metal flow and thus form fibers of increased strength along the direction of flow. Casting is a solidification process. Therefore, the microstructure can be finely tuned, such as grain structure, phase transformations and precipitation.
Originally, a “billet” commonly used in the 18th and early 19th centuries as a “billet of invitation.” A particular use of the word in this sense is to denote an order issued to a soldier entitling him to quarters with a certain person. From this meaning, the word billet came to be loosely used of the quarters thus obtained. Repeated petitions against the practice of billeting, starting in the 16th century, culminated in its outlawing in 1689 as an extension of a section of the Petition of Right 1628. During wartime, civilians who have been evacuated from a city in danger of attack are billetted in communal shelters or in the homes of individuals. The practice of billetting evacuees was widespread in Britain during World War II, particularly during the Blitz, when children and other non-essential persons in major cities were sent to rural areas for safety. In European countries since the formation of regular forces the Quartermaster was an occupation and a rank of the individuals responsible for provision of sleeping quarters as well as other provisions for regular time troops.