Metalworking by Karim

what are the processes that turn pig iron into steel?

karimmmmmm — 2024-03-10 08:51:52 UTC

the pig iron must first be extracted from iron by smelting in a blast furnace

karimmmmmm — 2024-03-10 08:52:58 UTC

the blast furnace is a ceramic refractory lined tall reactor

karimmmmmm — 2024-03-10 08:54:00 UTC

iron ore

karimmmmmm — 2024-03-10 08:54:25 UTC

coke

karimmmmmm — 2024-03-10 08:54:37 UTC

limestone

karimmmmmm — 2024-03-10 08:57:30 UTC

burns to form carbon monoxide, wich passes over the iron ore, reducing the iron oxides to metallic iron

karimmmmmm — 2024-03-10 08:58:36 UTC

absorbs impurities from the ore and forms fluid slag (wuch floats on the surface of the heavier molten iron

karimmmmmm — 2024-03-10 09:20:12 UTC

is kept in continuous operations and at intervals the iron and slag are run off separately

karimmmmmm — 2024-03-10 09:22:16 UTC

mixed in correct propotions in

karimmmmmm — 2024-03-10 09:28:07 UTC

the iron extracted from the blast furnace is known as pig iron

karimmmmmm — 2024-03-10 09:28:38 UTC

it contains a number of impurities and it's very brittle and difficult to work

karimmmmmm — 2024-03-10 09:29:34 UTC

it's converted into steel by removing most but no all of the impurities

karimmmmmm — 2024-03-10 09:30:20 UTC

the resulting steel is harder than iron bevaus is has been made with ad additional percentage of carbon

casting

karimmmmmm — 2024-03-12 18:46:22 UTC

is a method of shaping an object by pouring a liquid into a mould and letting it harder

advantages

karimmmmmm — 2024-03-12 18:49:23 UTC

often form the basis fot choosing casting over other shaping processes such as machining, forging, wilding and stamping

Some of the reasons for the success of the casting process are:

karimmmmmm — 2024-03-12 18:51:50 UTC

karimmmmmm — 2024-03-12 18:53:02 UTC

he most intricate shapes, both external and internal, may be cast. As a result, many other operations, such as machining, forging or welding can be minimised or eliminated

karimmmmmm — 2024-03-12 18:53:49 UTC

because of their physical properties, some metals can only be cast to shape since they cannot be hot-worked into bars, rods or plates

karimmmmmm — 2024-03-12 18:54:14 UTC

construction is simplified as objects can be cast in a single piece which would otherwise require assembly of several pieces

karimmmmmm — 2024-03-12 18:58:16 UTC

The most common types of casting are die-casting, sand casting and continuous or strand casting.

Die-casting

karimmmmmm — 2024-03-12 19:00:27 UTC

Die-casting is the process of forcing molten metal into the cavities of steel moulds under high pressure.

karimmmmmm — 2024-03-12 19:01:05 UTC

this process would probably be far more economical

There are four major steps in the die-casting process

karimmmmmm — 2024-03-12 19:01:36 UTC

karimmmmmm — 2024-03-12 19:02:18 UTC

First, the mould is sprayed with lubricant and closed.Molten metal is then injected into the die under high pressure. The high pressure assures a casting as precise and as smooth as the mould.Once the cavity is filled, the pressure is maintained until the casting has become solid.Finally, the die is opened and the casting is ejected.

sand casting

karimmmmmm — 2024-03-15 05:12:15 UTC

This method is a hot forming process applied to iron and steel parts. This hot forming process is used very frequently for the casting of industrial products and parts, such as engine blocks

karimmmmmm — 2024-03-15 05:12:59 UTC

In this process, heat is applied to soften the piece of metal. Metal is usually cast in a sand mould. When the metal has become solid, the mould is broken to remove the casting

Strand casting or continuous casting

karimmmmmm — 2024-03-15 05:13:53 UTC

is a refinement of the casting process for the continuous, high-volume production of metal sections with a constant cross-section.

karimmmmmm — 2024-03-15 05:15:02 UTC

Continuous casting provides a better quality product as it allows finer control over the casting process, along with the obvious advantages inherent in a continuous forming process