Case Study : Railway rail

Name of members:

MCT3033 - Manufacturing Technology

MUHAMMAD HAMBALI BIN ISMAIL D20111048828

MUHAMMED I’ZWAN BIN ABDUL KAHAR D20111048832

MOHAMAD NAZIR BIN AWANG KECHIL D20111048833

SITI RUQAIAH BINTI MD NOR D20111048831

HAZURAYAL AIZAL BT MAH HASSAN D20111048826

What is railway rail?

•Railway track is a set of two parallel rows of long pieces of steel.

•Used by trains to transport people or things from one place to another.

•The rails are supported by cross pieces set at regular intervals which spread the high pressure load imposed by the train wheels into the ground

TYPES OF MATERIAL USED

•Cast iron

•Wrought iron

•Ferrous scrap metal

Cast Irono Iron or ferrous alloy which has been heated until it liquefies, and is then poured into a mould to solidify.

o The alloy constituents affect its color when fractured.

o White cast iron has carbide impurities which allow cracks to pass straight through.

o Grey cast iron has graphitic flakes which deflect a passing crack and initiate countless new cracks as the material breaks.

Wrought Irono Iron alloy with a very low carbon (0.1 to 0.25) content in contrast to cast iron, and has fibrous inclusions (slag)

o Wrought iron is tough, malleable, ductile and easily welded

o It was known as commercially pure iron

o It no longer qualifies because current standards for commercially pure iron require a carbon content of less than 0.008 wt%.

o Before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron

Ferrous Scrap Metal

o Ferrous metals are able to be recycled with steel being one of the most recycled materials in the world.

o Ferrous metals contain an appreciable percentage of iron and the addition of carbon and other substances creates steel. 

THE PRODUCTION PROCESS OF THE PRODUCT

Melting (Blast furnace) Ladle refining furnaceVacuum degassing

systems

Continuous casterCut by Torch CuttingStoring for rolling mill

Reheating furnace

Ultrasonic test

Rolling mill

Eddy current testing machine

Non-Destructive tests Straightening Cooling bed

Branding and stamping

Cutting of length

Finishing Cold checking of straightness

1. Preparing the metal and loading 2. Melting the metal3. Refining and treating molten metals4. Holding molten metal5. Tapping molten metal6. Transporting molten metal 

1. Preparing the metal and loading 2. Melting the metal3. Refining and treating molten metals4. Holding molten metal5. Tapping molten metal6. Transporting molten metal 

The molten steel is transferred to the Ladle Refining Furnace

The steel is tested and fine adjustments are made to the composition and temperature to ensure the right characteristics for the desired grade of steel to be produced 

The molten steel is transferred to the Ladle Refining Furnace

The steel is tested and fine adjustments are made to the composition and temperature to ensure the right characteristics for the desired grade of steel to be produced 

The effective removal of hydrogen, oxygen and/or carbon, based on proven technology and experience.

The tank type ladle degassers achieve low sulfur levels, remove carbon, and improve floatation of oxide inclusions, allowing them to be entrained in the slag.

The vacuum can be produced by an all-steam ejector pumping system, mechanical pumps, or a combination steam ejectors and pump system

The effective removal of hydrogen, oxygen and/or carbon, based on proven technology and experience.

The tank type ladle degassers achieve low sulfur levels, remove carbon, and improve floatation of oxide inclusions, allowing them to be entrained in the slag.

The vacuum can be produced by an all-steam ejector pumping system, mechanical pumps, or a combination steam ejectors and pump system

The steel is poured into molds, cooled and shaped into the desired cross section, essentially forming a long bar called a billet.

Recent investments in mould electromagnetic stirring and dynamic spray control ensure cast bloom consistency, with minimal segregation and no hinge, side or corner cracks.

The steel is poured into molds, cooled and shaped into the desired cross section, essentially forming a long bar called a billet.

Recent investments in mould electromagnetic stirring and dynamic spray control ensure cast bloom consistency, with minimal segregation and no hinge, side or corner cracks.

As the billets move through the continuous caster, they are cut by TORCH CUTTING into desired lengths.

As the billets move through the continuous caster, they are cut by TORCH CUTTING into desired lengths.

The completed billets are used as the feedstock (storing) for  rolling millThe completed billets are used as the feedstock (storing) for  rolling mill

The hot rolling process begins by reheating the previously created billets in reheating furnace until they turn into a malleable  state. The hot rolling process begins by reheating the previously created billets in reheating furnace until they turn into a malleable  state.

The reheated billets exit the reheat furnace and proceed to the rolling mills.

Each rolling mill consists of a series of "stands", each containing a set of rollers that compress and lengthen the billets and then finish them into the desired.

Water is used to keep the equipment from overheating.

The reheated billets exit the reheat furnace and proceed to the rolling mills.

Each rolling mill consists of a series of "stands", each containing a set of rollers that compress and lengthen the billets and then finish them into the desired.

Water is used to keep the equipment from overheating.

During the final rolling pass, rails are relief-branded with the rail profile, steel grade and year and site of manufacture. After leaving the finishing stand, the rails are hot stamped with a unique identification mark for permanent traceability.

During the final rolling pass, rails are relief-branded with the rail profile, steel grade and year and site of manufacture. After leaving the finishing stand, the rails are hot stamped with a unique identification mark for permanent traceability.

The conveyors are each other independent moving rails on the cooling bed. In this way the bars are positioned with a curve which straightens out during cooling.

All is aimed at reducing to a minimum the mechanical pressures necessary for straightening and consequently at reducing internal stresses.

The advancement of the rails is obtained by a “walking-beam” system straightening plant.

The conveyors are each other independent moving rails on the cooling bed. In this way the bars are positioned with a curve which straightens out during cooling.

All is aimed at reducing to a minimum the mechanical pressures necessary for straightening and consequently at reducing internal stresses.

The advancement of the rails is obtained by a “walking-beam” system straightening plant.

The straightening line has two straightening units positioned after the cooling bed.

The straightening pressures are applied onto the relevant axis at the rail height for vertical straightening and onto the head sides for horizontal straightening

The straightening line has two straightening units positioned after the cooling bed.

The straightening pressures are applied onto the relevant axis at the rail height for vertical straightening and onto the head sides for horizontal straightening

The increasing requirement for products with fewer surface defects derives from a variety of different reasons such as

Safety in use, Operational reliability, Extension of life cycle, Travel comfort, Track geometry, Increased speed, IIncreased axial loads, Increased railway traffic.

The NDT system has been specifically developed and created for controlling all rail profiles required by the market.

The increasing requirement for products with fewer surface defects derives from a variety of different reasons such as

Safety in use, Operational reliability, Extension of life cycle, Travel comfort, Track geometry, Increased speed, IIncreased axial loads, Increased railway traffic.

The NDT system has been specifically developed and created for controlling all rail profiles required by the market.

Used to detect any surface imperfections that exceed specification limits.

Rails also require a uniform internal metallurgical structure to ensure strong performance, and any irregularities that could adversely affect the rail’s in-service life are detected using in-line ultrasonic testing.

Any defects identified are checked manually using portable ultrasonic equipment.

Used to detect any surface imperfections that exceed specification limits.

Rails also require a uniform internal metallurgical structure to ensure strong performance, and any irregularities that could adversely affect the rail’s in-service life are detected using in-line ultrasonic testing.

Any defects identified are checked manually using portable ultrasonic equipment.

The Ultrasonic examination is carried out in a continuous and automatic mode soon after the Eddy current test.

The defects detected by the Eddy current and ultrasonic control systems are processed in real time and signaled to the technicians on monitors and on inspection reports.

The defect detected is highlighted on the rail by means of an automatic paint spray.

The Ultrasonic examination is carried out in a continuous and automatic mode soon after the Eddy current test.

The defects detected by the Eddy current and ultrasonic control systems are processed in real time and signaled to the technicians on monitors and on inspection reports.

The defect detected is highlighted on the rail by means of an automatic paint spray.

After the checks with the NDT system the rails are cut to length and drilled if required, by means of a dedicated facilityAfter the checks with the NDT system the rails are cut to length and drilled if required, by means of a dedicated facility

Straightness is checked by means of a no-contact high definition cameras system.

The system is completely static and does not require any electro- mechanical positioning.

The processed data are recorded and a reporting is generated.

The control is performed on the final rail length.

Straightness is checked by means of a no-contact high definition cameras system.

The system is completely static and does not require any electro- mechanical positioning.

The processed data are recorded and a reporting is generated.

The control is performed on the final rail length.

After cold cutting and straightness control, the rails are transferred to the inspection bed for the final controls. 

After cold cutting and straightness control, the rails are transferred to the inspection bed for the final controls. 

HEAT TREATMENT PROCESS

Metals and alloys:• May not posses all the desired properties in the finished product• Alloying and heat treatment are two methods which are extensively used for controlling material properties.

In Heat Treatment:• The microstructures of materials are modified.• The resulting phase transformation influences mechanical properties like strength, ductility, toughness, hardness and wear resistance.

Purpose of Heat Treatment:• Is to increase service life of a product by increasing its strength or hardness, or prepare the material for improved manufacturabilit

HardeningAnnealingNormalizingTemperingSurface Hardening

THE SUITABLE HEAT TREATMENT PROCESS FOR THE

PRODUCT

Hardening of steels is done to increase the strength and wear properties

One of the pre-requisites for hardening is sufficient carbon and alloy content. If there is sufficient Carbon content then the steel can be directly hardened.

Otherwise the surface of the part has to be Carbon enriched using some diffusion treatment hardening techniques.

1.Quenching: Quench hardening is a mechanical process in

which steel and cast iron alloys are strengthened and hardened. These metals consist of ferrous metals and alloys. This is done by heating the material to a certain temperature. This produces a harder material by either surface hardening or through-hardening varying on the rate at which the material is cooled. Items that may be quenched include gears, shafts, and wear blocks.

2.Case Hardening:Is the process of hardening the surface of a metal,

often a low carbon steel, by infusing elements into the material's surface, forming a thin layer of a harder alloy.

How it’s made???