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Below are some common terms encountered in the importing and exporting of steel plate. You can use the search box below to search the Oakley Steel site or scroll down through the glossary. We hope that it helps.

The steel industry has a specialised vocabulary

The steel industry has a specialised vocabulary

Annealing

A general term referring to various heat treatments that can reduce hardness, improve machinability or obtain various physical or mechanical properties.

As Rolled

Describes the surface condition of the plate after the completion of rolling.

ASME

American Society of Mechanical Engineers.

ASME Boiler and Pressure Vessel Code

Specifies requirements for the design, fabrication and inspection of boilers and pressure vessels ensuring that there is a sufficient safety margin to mitigate the effects of deterioration in service.

ASTM

American Society for Testing and Materials.

Boiler

A boiler is a closed vessel in which gases or liquids are heated. In general terms a boiler is a type of pressure vessel.

Boiler Plate

Steel plate designed and manufactured specifically for use in boilers and pressure vessels.

Carbon Steel

Carbon steel is an alloy of iron and carbon with less than 2% carbon and less than 1.65% manganese and traces of other elements.

Closing Date

The closing date is last date at which cargo can be delivered to a vessel in order for it to be loaded prior to sailing. This is generally about a week before the sailing date.

CLR – Crack to Length Ratio

EN10027

EN10027 sets out the naming conventions for European steels.

EN10028

European Standard specifying the requirements for flat steel products for use in pressure vessels. Part 2 covers alloy and non–alloy steel for elevated temperatures. Part 3 specifies weldable fine grain steels.

EN10204

European Standard specifying the types of inspection documents required for metallic products BS EN 10204:2004.

Fine Grain

A fine grained steel is composed of small grains.

Fully Killed

A steel that has been thoroughly deoxidised so that no reaction occurs between carbon and oxygen as it solidifies.

Fully Killed

A steel that has been thoroughly deoxidised so that no reaction occurs between carbon and oxygen as it solidifies.

Hardening

Increasing the hardness of the steel by various types of heating and cooling.

Heat

A term used to describe a lot, or batch, of steel produced as one unit.

Heat Number

An identifying number used to uniquely identify different heats for quality and traceability purposes.

Heat Treatment

Heat treatment is the heating and cooling of steel in order to achieve certain desired properties.

HIC – Hydrogen Induced Cracking

“Planar cracking that occurs in carbon and low alloy steels when atomic hydrogen diffuses into the steel and then combines to form molecular hydrogen at the trap site.” NACE MR0175/ISO 15156 – 12001(E)

Incoterms 2000

A standard set of commercial terms apportioning responsibilities for carriage and delivery of goods between buyers and sellers in international trade.

ISO 15156

International standard giving requirements and recommendations for the selection of steels for use in H²S environments in the Oil and gas industry. It is also known as NACE MR0175.

Low Alloy Steel

A low alloy steel generally has alloying elements added to it in greater quantities than for carbon steel, but which are usually l ess than 5%.

Mill Test Certificate (MTC)

A certificate issued by a steel mill in accordance with EN 10204 which gives the test results for the steel plate and which states its compliance with the steel specification.

MR0103

MR0103 is a NACE standard that defines material requirements for use in sour refinery process environments where resistance to Sulphide Stress Cracking (SSC) is required.

MR0175

NACE International standard giving requirements and recommendations for the selection of steels for use in H²S environments in the Oil and gas industry. It is also known as ISO15156.

NACE

Formerly the National Association of Corrosion Engineers it is the leader in corrosion engineering and premier authority for corrosion control solutions. It publishes MR0175 and other corrosion related standards.

Normalising

Normalising heats a steel plate to above the transformation range and then air cools it to below the transformation range. This makes the grain structure homogenous and increase the machinability of the steel.

Plate

Flat hot rolled steel over 6mm thick.

Pressure Vessel

A closed vessel designed to contain gases or liquids at pressures other than those of the ambient environment. A boiler is a type of pressure vessel.

PWHT – Post Weld Heat Treatment

In PWHT welds are heated immediately after welding in order to relieve stresses and to prevent the formation of a hard or brittle microstructure in the steel.

Quenching

The steel is cooled rapidly.

Rolling

Rolling is the process of turning steel slabs into plate in a steel rolling mill.

Sailing Date

The actual date that a vessel sails; however the important date for steel shipping is the closing date.

SSC – Sulphide Stress Cracking

“SSC is defined as a cracking of a metal under the combined action of tensile stress and corrosion in the presence of water and H2S. SSC is a form of hydrogen stress cracking resulting from the absorption of atomic hydrogen that is produced by the sulphide corrosion reaction on the metal surface.”
NACE MR0103 – 2007 p.1

Stainless Steel

We don’t sell it but for completeness it has a minimum chromium content of 10.5% and a maximum carbon content of 1.8%

Structural & Pressure Steels

The first symbol defines the type of application:

       S – Structural – construction steels
       P – Pressure – pressure vessels and boilers
       The three number combination that follows the initial letter is the minimum yield strength of the        thinnest plate of that specification. So for example P355GH will have minimum yield strength of 355        MPa for plates less than or equal to 16mm thick and is suitable for elevated temperature use (H).
       For construction steels further symbols can be added.

Charpy Impact Test Value – J, K and L indicate impact values of 27 Joules, 40 Joules and 60 Joules respectively
Testing Temperature – The temperature at which the test is conducted
- R 20°C
- 0°C
- 2 – 20°C
- 3 – 30°C
- 4 – 40°C
- 5 – 50°C
- 6 – 60°C
General Characteristics
- W – Weather resistant – i.e. S355J2W+N
- G1 – Not killed
- G2 – Not killed not allowed
- G3 – normalised or normalised rolled i.e S355J2G3
- G4 – mills decision to normalise or not – usually not.

For pressure vessel steels further symbols can be added.

N – normalised
H – elevated temperature
L – low temperature – Impact testing at – 50°C
L1 – Special low temperature – impact testing at – 50°C
L2 – Special low temperature – impact testing at – 50°C
G – other characteristic follows

For non alloy carbon steel with a manganese content of greater than 1% the first figure is the average carbon content multiplied by 100. This is followed by the chemical symbols that are characteristic of the steel. The final figure is the characteristic elements of the steel multiplied by a factor. For Cr, Co, Mn, Ni, Si and W the factor is 4. For Al, Be, Mo, Nb, Pb, Ta, Ti, V and Zr the factor is 10. So for 13CrMo4–5 the average carbon content is 0.13%. The principal elements that give the steel its characteristics are Chrome and Molybdenum. The Chrome is 1% of the content and the Molybdenum is 0.5% of the content.

Tempering

Reheating a quenched steel and then cooling it again.

TM0284

A NACE standard that specifies a test method to be used when evaluating steels for resistance to Hydrogen Induced Cracking (HIC) due to hydrogen absorption of aqueous sulphide corrosion.

Yield Strength

The stress at which the material exhibits a specified deviation from the proportionality of stress to strain.

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