There are 2 basic types of metallic materials 1)

Castings.

Wrought Products.

Most metals and alloys commence life in the form of casting and may remain as a Cast Product

Materials Inspection

Castings During the solidification process a primary pipe will be

formed at the final point of cooling and solidification at

the centre at the surface of the ingot.

A secondary pipe or shrinkage cavity may also be

formed directly beneath this, as in B below

These pipes will also contain any low melting point

impurities i.e. sulphur and phosphorous

Castings

Smelting Defects Non-metallic inclusions

Rolling In primary rolling the heated ingot is rolled backwards

and forwards through a reversing mill

The ingot is plastically deformed under compressive

forces into a section until it is almost 1/3 rd of the

ingots CSA

RollingBloom - Square c/s 150x150mm minimum

Slab - Rectangular c/s area greater than 14400 mm2

Billet - Square 50x50 up to 120 x 120mm

Primary rolling- ingot to blooms and slabs

Secondary rolling - blooms and slabs to plates , sheets etc

PresenterPresentation Notes10 steps bloom to bar stock

Rectangular metallic forms Rectangular metallic forms can generally be defined by

their thickness as follows

< 0.01mm Leaf

0.01 0.10 mm Foil

0.10 3.00 mm Sheet

3.00 50.00mm Plate

> 50.00mm Slab

Steel Production

PresenterPresentation NotesOne integrated process lengths of metal cut

Rolling

Two-High Reversing Mill

Ingots, slabs and billets rolled to produce long length products with uniform cross section

PRIMARY ROLLING PROCESS

PresenterPresentation NotesRolling achieves reduction in thickness, increase in length and negligible increase in width Ingot placed in soaking pits to reach 1200 degrees C

Hot rolling refines the grain structure and improves ductility and requires less energy (recrystalisation)

Rolling can close up and weld up internal defects such as porosity and shrinkage cavities

Gross inclusions are elongated IN THE DIRECTION OF WORKING

Rolling

Two-High Reversing Mill

PRIMARY ROLLING PROCESS

Secondary piping

PresenterPresentation NotesRolling achieves reduction in thickness, increase in length and negligible increase in width Ingot placed in soaking pits to reach 1200 degrees C

Hot rolling refines the grain structure and improves ductility and requires less energy (recrystalisation)

Rolling can close up and weld up internal defects such as porosity and shrinkage cavities

Gross inclusions are elongated IN THE DIRECTION OF WORKING

Rolling

Three-High Reversing Mill

SECONDARY ROLLING PROCESSLamination

PresenterPresentation NotesRolling achieves reduction in thickness, increase in length and negligible increase in width Ingot placed in soaking pits to reach 1200 degrees C

Hot rolling refines the grain structure and improves ductility and requires less energy (recrystalisation)

Rolling can close up and weld up internal defects such as porosity and shrinkage cavities

Gross inclusions are elongated IN THE DIRECTION OF WORKING

Rolling

Two-High Reversing Mill

PRIMARY ROLLING PROCESS

Non-metallic inclusion

PresenterPresentation NotesRolling achieves reduction in thickness, increase in length and negligible increase in width Ingot placed in soaking pits to reach 1200 degrees C

Hot rolling refines the grain structure and improves ductility and requires less energy (recrystalisation)

Rolling can close up and weld up internal defects such as porosity and shrinkage cavities

Gross inclusions are elongated IN THE DIRECTION OF WORKING

Rolling

Three-High Reversing Mill

SECONDARY ROLLING PROCESSStringers

PresenterPresentation NotesRolling achieves reduction in thickness, increase in length and negligible increase in width Ingot placed in soaking pits to reach 1200 degrees C

Hot rolling refines the grain structure and improves ductility and requires less energy (recrystalisation)

Rolling can close up and weld up internal defects such as porosity and shrinkage cavities

Gross inclusions are elongated IN THE DIRECTION OF WORKING

Rolling

Two-High Reversing Mill

PRIMARY ROLLING PROCESS

Segregation of metals

PresenterPresentation NotesRolling achieves reduction in thickness, increase in length and negligible increase in width Ingot placed in soaking pits to reach 1200 degrees C

Hot rolling refines the grain structure and improves ductility and requires less energy (recrystalisation)

Rolling can close up and weld up internal defects such as porosity and shrinkage cavities

Gross inclusions are elongated IN THE DIRECTION OF WORKING

Rolling

Three-High Reversing Mill

SECONDARY ROLLING PROCESSBanding

PresenterPresentation NotesRolling achieves reduction in thickness, increase in length and negligible increase in width Ingot placed in soaking pits to reach 1200 degrees C

Hot rolling refines the grain structure and improves ductility and requires less energy (recrystalisation)

Rolling can close up and weld up internal defects such as porosity and shrinkage cavities

Gross inclusions are elongated IN THE DIRECTION OF WORKING

Cold Rolling Initial rolling hot Finishing by cold working

Cluster mill 4 High mill

PresenterPresentation NotesHot rolling achieves reductions in cross section but not dimensional accuracy

Cold rolling gives dimensional accuracy , increased strength and surface finish

MATERIALS INSPECTION All materials arriving on site should be inspected for

Size

Condition

Type/Specification/Schedule

Storage

Rolling Imperfections

LaminationsSegregation

Cold Laps*

Direction of rolling

PLATE INSPECTION

Size

Condition

(Corrosion, Mechanical damage, Laps, Bands & Laminations)

Specification

Other checks may need to be made such as: distortion tolerance, number of plates and storage*

Plate Inspection

Lapping

Lapping

Lapping

Lamination

Pipe InspectionCondition

(Corrosion, Damage, Wall thickness Ovality, Laminations & Seam)

Specification

Welded seam

Size

5l

MATERIALS INSPECTION

Other checks may need to be made such as: distortion tolerance, number of plates and storage*

Materials InspectionSlide Number 2CastingsCastingsSmelting DefectsRollingRollingRectangular metallic formsSlide Number 9RollingRollingRollingRollingRollingRollingRollingCold RollingMATERIALS INSPECTIONPlate InspectionPLATE INSPECTIONPlate InspectionLappingLappingLappingLaminationMATERIALS INSPECTION