Wrought iron

WROUGHT IRON

Submitted By :

Moksha Bhatia

1461576

• Wrought iron is an iron alloy which is soft, ductile, fibrous variety.

• It usually contains less than 0.1 percent carbon and 1 or 2 percent slag.

• It is superior for most purposes to cast iron, which is overly hard and brittle owing to its high carbon content.

• Wrought iron can be easily welded.

INTRODUCTION

Manufacturing of Wrought Iron

• Wrought iron is manufactured from process of puddling of cast iron.

• This involves reheating cast iron and manually mixing air in with the molten mass.

• Puddling, by which the molten metal is still further exposed to a blast of air .

BLOOMERY PROCESS

• the bloomery is preheated by burning charcoal, and once hot, iron ore and additional charcoal are introduced through the top, in a roughly one to one ratio

• Air was blown in through a tuyere to heat the bloomery to a temperature somewhat below the melting point of iron.

• Slag would melt and run out, and carbon Monoxide from the charcoal would reduce the ore to iron.

• The mixed iron and slag cool to form a spongy mass referred to as the bloom

• Because the bloom is highly porous, and its open spaces are full of slag, the bloom must later be reheated and beaten with a hammer to drive the molten slag out of it. Iron treated this way is said to be wrought (worked), and the resulting iron, with reduced amounts of slag is called wrought iron or bar iron.

• After smelting was complete, the bloom was removed, and the process could then be started again

FINERY PROCESS

• In the 15th century, the blast furnace spread in belgium and it was improved furthur.

• Pieces of cast iron were placed on a finery hearth.

• On finery hearth charcoal was being burned with a plentiful supply of air so that carbon in the iron was removed by oxidation, leaving semisolid malleable iron behind.

• It was in turn replaced by the puddling process

HEARTH

HAMMER

CHARCOAL

PUDDLING PROCESS

• Method of converting pig iron into wrought iron by subjecting it to heat and frequent stirring in a furnace.

• It was the first method that allowed wrought iron to be produced on a large scale.

ASTON PROCESS

• In 1925, James Aston of the United States developed a process for manufacturing wrought iron quickly and economically.

• It involves taking molten steel from a Bessemer converter and pouring it into cooler liquid slag.

• The molten steel contains a large amount of dissolved gases so when the liquid steel hits the cooler surfaces of the liquid slag the gases are liberated

• The molten steel then freezes to yield a spongy mass having a temperature of about 1370 °C.

• . This spongy mass must then be finished by being shingled and rolled.

Availability in Market

• Bar Iron includes simple sections - round, square, or flat. Ordinary dimensions are generally from 1/2 inch to 3 inches diameter, or sides, increasing by 1/16 of an inch each size. If under 1/2 an inch diameter, they are classed as rods; or if under 3/16 inch diameter, as wire.

• Flat Bars. - The ordinary dimensions are generally from 1 foot by 1/4 of an inch to 6 inches by 1 inch, the width increasing 1/8 of an inch and the thickness increasing 1/16 of an inch (at the same time) in the various sizes. Bars of these sections may be readily obtained of to 22 feet in length without extra charge.

HISTORY OF WROUGHT IRON

• Due to its malleability and toughness, wrought iron has been coveted for thousands of years..

• Throughout time, wrought iron has been used to build ancient structure, warships and railways.

• Around 8th century B.C., armies were equipped with iron swords.

• 18th century – led to beautiful railings and gates throughout London.

• Demand for wrought iron reached its peak in the 1860s with the adaptation of iron clad warships and railways, balconies, porches and verandhas, canopies, roof cresting, lamps, grilles, hardware, etc.

• Then it began to be used as structural member such as tie rods

• Today wrought iron can be found anywhere in homes from light fixtures, to wine racks, to candle holders.

Uses of Wrought Iron

Exterior of Carson Pirie Scott building by Louis Sullivan

EIFFEL TOWER - PARIS

Iron pillar of Delhi, India, containing 98% wrought iron

RAILING

WROUGHT IRON DOOR

WROUGHT IRON SIGN

WROUGHT IRON GATE

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