The Making of Steel: Then & Now

PREPARED BY: Maria Reza J. Nebril, RME

Revision: 1 / Date: 07 April 2015

OBJECTIVES

To have a basic knowledge and

understanding about:

As used in engineering work, steel may be cast in molds into shape (steel castings) or into blocks (ingots) of cast steel which are rolled or hammered into shape. Rolled or hammered steel is, in general, stronger, more ductile and tougher than are steel castings of the same chemical composition. Carbon and iron are the principal ingredients in steel, but special steels of great strength and toughness are made by alloying carbon and iron with other elements. Common alloy steels are: nickel steel, chrome-nickel steel, tungsten steel, vanadium steel, and manganese steel.

A general term for iron containing small amounts of carbon, manganese and other elements.

Steel is manufactured from pig iron by the open-hearth process, the Bessemer process, or the electric furnace process, or by a combination of these processes. Special high grades of steel are manufactured from wrought iron by the crucible involve fusion. All grades of steel are fusible and malleable.

Wrought iron is a soft, ductile, fibrous variety that is produced from a semi fused mass of relatively pure iron globules partially surrounded by slag

Ingot is a material, usually metal, that is cast into a shape suitable for further processing

Steel can be plain carbon steel or alloyed steel

Plain carbon steel is never used for rolls

All roll grades contain some alloys

For hot rolling most steel rolls are cast

For cold rolling most steel rolls are forged

Steel is an alloy (mixture) of iron (Fe) and carbon (C).

Small additions of Carbon < 0.90 % are steels – Cast Carbon Steel

More carbon 1.0%-2.5% are semi- steels or (ADAMITE) GT and all Steel base grades

LUSTER - It is a shiny metal with a very attractive finish (architecture, cutlery, appliances).

TENSILE STRENGTH - It is very strong and resistant to fracture (building frames, security doors, trains, ships).

MALLEABILITY - It can be rolled into thin sheets, rod, bar or beams (roofing, structural) or forged into different shapes (gears, tolls).

ALLOYING - Adding other chemicals can change steel’s properties. Stainless Steel contains the elements chromium, nickel and molybdenum to make rust resistant for use in kitchens. Manganese us added to increase toughness, while steel for rods has tungsten and cobalt to keep even when it gets hot.

CONDUCTIVITY - It transfers heat and electricity.

COATING - Steel can be coated with different substances, such as metals like tin, or plastics or paint.

In the automobile sector: cars, ships, airplanes

For everyday uses: cans, pots, containers, etc. At the food preservation

In energy In communications In health

The purpose of a blast furnace is to reduce and convert iron oxides into liquid iron called "hot metal".

To produce iron, a charge of ore, coke, and limestone are dropped into the top of a blast furnace.

Hot gases are forced into the lower part of the chamber at high rates to accomplish combustion and reduction of the iron

Iron OreLimestone

Coke (Coal)

Since the mid-1800s, a number of processes have been developed for refining pig iron into steel.

Today, the two most important processes are Basic oxygen furnace (BOF) & Electric furnaceBoth are used to produce carbon and alloy steels.

Basic Oxygen Process which uses pure oxygen to convert a charge of liquid blast-furnace iron and scrap into steel. 

The basic oxygen furnace (BOF) is a refractory-lined, tiltable converter into which a vertically movable, water-cooled lance is inserted to blow oxygen through nozzles at supersonic velocity onto the charge 

Scrap iron and scrap steel are primary raw materials.

It is usually made in smaller amounts, and electricity is used for heating.

Electric furnaces are used to make specialized kinds of steel.

Usually associated with production of alloy steels, tool steels, and stainless steels- Noted for better quality steel but higher cost per ton, compared to BOF.

Steels produced by BOF or electric furnace are solidified for subsequent processing either as cast ingots or by continuous casting.

– Casting of ingots – a discrete production process– Continuous casting – a semi-continuous process

Steel ingots discrete castings weighing from less than one ton up to 300 tons (entire heat).

Molds made of high carbon iron, tapered at top or bottom for removal of solid castingThe mold is placed on a platform called a stool.

After solidification the mold is lifted, leaving the casting on the stool.

Continuous casting is widely applied in aluminum and copper production, but its most noteworthy application is steel-making.

Dramatic productivity increases over ingot casting, which is a discrete process.

For ingot casting, 10-12 hr may be required for casting to solidify.

Continuous casting reduces solidification time by an order of magnitude.

Flat products

Squares, rounds

Beams, channels

A chill is an object used to promote solidification in a specific portion of a metal casting mold. Normally the metal in the mold cools at a certain rate relative to thickness of the casting. When the geometry of the molding cavity prevents directional solidification from occurring naturally, a chill can be strategically placed to help promote it.

Static casting involves pouring a liquid metal into a mold, which contains a hollow cavity of the desired shape, and then is allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.

The molten metal is poured into a spinning die. The die can be spinning either on a vertical or horizontal axis depending on the configuration of the desired part. Ring and cylinder type shapes are cast vertically; tubular shapes are made with the horizontal centrifugal process. Either process may be used to produce multiple parts from just one casting.Because of the high g-forces applied to the molten metal in the spinning die, less dense material, including impurities, “floats” to the I.D. where it is subsequently removed by machining. Solidification is managed directionally under pressure, from the O.D. to the I.D., avoiding any mid-wall shrinkage, leaving a defect-free structure without cavities or gas pockets.

Softening during heat treatment is a function of high temperature followed by slow cooling to ambient temperature which is the normal work place temperature.

Hardening on the other hand is a function of high temperature followed by fast cooling, maybe by water sprays, even for very large castings. Stress relief or tempering, is the action of finally allowing the stress contours to develop into a safe state, and to allow stabilization by small changes to the microstructure, so that these changes do not take place when the roll is heated up in the hot rolling mill.

There are several different basic types of heat treatment which allow the casting to be softened, hardened or just relieved of internal stresses.

•Facing•Turning•Tapering•Threading•Boring•Grooving/Slotting•Polishing

Machining

Final Inspection Process

All rolls are fully examined by BRC inspectors before they are dispatched. The comprehensive inspection process includes critical dimensions, hardness and production parameters.

BRC’s patented Steel Packaging® also has the added benefit of simplifying the logistics process from foundry to mill. Unlike its wood counterpart, steel packaging does not need to undergo official fumigation treatment and verification for international shipments, thus saving time at key phases of transportation and ultimately cutting delivery lead-time.

BRC is extremely committed to its environmental responsibility. All our steel skids are reusable and recyclable: they can be used to store rolls at our customers’ mills, or can easily be melted back for scrap.

Since we introduced the Steel Packaging® methodology in the market, more and more of our keen competitors both locally and globally are using this methodology, which means more and more trees are saved. We are delighted to be the pioneer of the industry in greening-our-world.

Shipping Marks

In BRC Shipping mark when there is no required from client, default is: BRCPO NO.

SHIPPING MARKS

An identification label affixed to a container which specifies contents of the shipping container. If the merchandise is subject to any inspections such as an FDA inspection, the shipping label must contain that inspection information as well. A shipping label used by a mail carrier lists the originating and destination addresses.

- an identifying word, number, or symbol placed on freight to designate the consignee, destination, weight, and related information

Metallurgy Fifth Edition copyright 2012 American Technical Publishers Inc.Text-book of the Materials of Engineering (1917) by Herbert F. MooreGeneral Properties of Steels by Terence BellThe Encyclopedia BritannicaAn Introduction to Iron and Steel Processing, KAWASAKI STEEL 21st Century c 2003Engineering Materials by Haseeb Jatoihttp://www.brcil.com/en/qualitycontrolhttp://www.businessdictionary.com

Thank you