Steel_grades

Steel grades

Steel grades

Classification system

Steel grades to classify various steels by their composition and physical properties have been developed by a number of standards organizations.

Steel grades standards by country

Note that an increasing number of national European standards (DIN, AFNOR, UNE, UNI, etc.) and UK standards are being withdrawn and replaced by European Standards (EN). This task is carried out by the Comité Européen de Normalisation (CEN) (European Committee for Standardization).

European standard steel grades

EN 10027-1 steel grade designation system.

European standard steel grade names fall into two categories:[1]

  1. Steel specified by purpose of use and mechanical properties.
  2. Steel specified by chemical composition.

The inclusion of a letter 'G' before the code indicates the steel is specified in the form of a casting.

Category 1 : steel specified by purpose of use and mechanical properties

Basic grade designations for category 1 steels consist of a single letter (designating application) then a number signifying the mechanical property (often yield strength) dictated in the standard for that application designation. For some application designations another letter is included before the property value, this number is used to indicate any special requirements or conditions. These additional letters and values depend entirely on the application of the steel and are specified in the standard and far too numerous to mention here.

The next set of 3 digits gives the steel's minimum yield strength. So S355 has a minimum yield strength of 355 MPa for the smallest thickness range covered by the relevant standard – i.e. EN10025.[2]

Below is a table indicating the most common application codes.

More information Application symbol, Meaning ...

Additional symbols

In addition to the above category codes there are symbols that can be added to the grade code to identify any additional compositional requirements, delivery conditions, mechanical properties, &c. These values depend solely on the type/application code given in the first part of the code and are so numerous as to be impossible to indicate here. Additional symbols are separated from the main code by the plus sign (+).

The most common additional symbols are the impact and temperature codes for structural steels, category 1 - Sxxx.

More information Impact Resistance, Temperature ...

Example : S355J2

Delivery condition codes are also relatively common, the most common being:

More information Code, Condition ...

Example : S355J2+N

Electrical steel

Electrical steel type of product letters (bold are most recent version 2016):

More information Code, Maximum specific loss expressed for magnetic induction ...

Standard per steel name

According to EN 10027-1

More information Application, Mechanical property ...

Category 2 : Steel specified by chemical composition

In addition to the descriptive steel grade naming system indicated above, within EN 10027-2 is defined a system for creating unique steel grade numbers. While less descriptive and intuitive than the grand names they are easier to tabulate and use in data processing applications.

The number is in the following format: x.yyzz(zz)
Where x is the material type (only 1 is specified so far), yy is the steel group number (specified in EN10027-2) and zz(zz) is a sequential number designated by the certifying body, the number in brackets being unused but reserved for later use.

The steel groups are indicated below:

More information Code, Type ...

The current certification body is the VDEh in Düsseldorf, Germany.

Comparisons

Below is a table comparing steel grades from different grading systems.

More information EN steel number (Europe), EN steel name (Europe) ...

American Petroleum Institute (API) steel grades

Color coding

In order to clearly distinguish the steel grade, tubing, casing and its coupling should be painted with color codes respectively. Color bands should be painted on tubing and casing body longer than 600mm to either end. The whole outer-body of the coupling needs to be painted color and then color codes

More information Coupling, Tubular Body ...

API 5B and 5CT provide various steel grades and color codes of each grade, offering detailed and overall information of casing and tubing, which help you clearly pick out the most suitable products for different well application.

References

Notes

  1. [1]
    EN 10027, European Committee for Standardization
  2. [2]
    "EN 10027 Steel Names and their Meaning".
  3. [3]
    https://www.3ppars.com/WebsiteImages/download/48771479212.PDF [bare URL PDF]
  4. [4]
    Bringas, John E, ed. (2016). Handbook of Comparative World Steel Standards, 5th Edition. doi:10.1520/ds67d-eb. ISBN 978-0-8031-7077-3. Retrieved 2022-04-28.
  5. [5]
    "Standards comparison". Retrieved 2008-12-31..
  6. [6]
    Oberg, pp. 411-412.
  7. [7]
    "1045 Steel". steel-bar.com. 16 May 2022.
  8. [8]
    "Chronifer M-15 X (431 X) steel developed by L. Klein SA". www.kleinmetals.ch. Retrieved 2017-01-12.
  9. [9]
    AISI A2, Efunda, archived from the original on 2010-05-15, retrieved 2010-12-25.
  10. [10]
    AISI A3, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  11. [11]
    AISI A4, Efunda, archived from the original on 2010-05-15, retrieved 2010-12-25.
  12. [12]
    AISI A6, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  13. [13]
    AISI A7, Efunda, archived from the original on 2010-12-25, retrieved 2010-12-25.
  14. [14]
    AISI A8, Efunda, archived from the original on 2010-05-15, retrieved 2010-12-25.
  15. [15]
    AISI A9, Efunda, archived from the original on 2010-05-15, retrieved 2010-12-25.

Bibliography

  • Oberg, E.; et al. (1996), Machinery's Handbook (25th ed.), Industrial Press Inc, ISBN 3540311874
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