Disclaimer: The information on this page has not been checked by an independent person. Use this information at your own risk.

Home

Matter Index

Strength Steels..

Steel Selection Based on European Standards

Important Note: All information on this page has been interpreted from the relevent Standard, Books, Other Web Sites, and Leaflets. This information is of a general nature for initial guidance. Selection of materials for use must be by communication with the suppliers and by reference to the appropriate codes

Introduction

Since 1988 a new series of 'mandatory'European standards (EN = Europaischen Normen) has been created, to replace national standards, such as BS, DIN, SS and NF, throughout 18 countries of Western Europe. EN are a part of the 'Single Market' legislation, designed to give equal opportunities for firms to compete throughout Europe, by harmonising the technical requirements between countries. The national standards bodies, of which BSI is one, are required to officially withdraw their national standards, when an EN is created with the same scope of application.

Consistent pattern of Standards

The aim is to produce a logical, common pattern,in which items are standardised in one document only, reference being made to this document from other standards. For example, tensile testing methods are standardised in a different document to material property values, and dimensional tolerances in other separate standards. Thus, changed requirements need only to be written into one document.

Implementation of EN

The fact that BSI and the other national bodies publish EN does not compel people to use them. (Note the continued use of the BS 'Emergency Number' (also En) series of steels years after they have been officially replaced.) Only when suppliers and customers fully accept and understand European Standards, will it actually happen.

Review of Standards

EN 10025- Hot Rolled Products of non-alloy steel

Steel Names according to EN 10025 in form of ....X(1) nnn(2) Xn (3) Xn(4).....Ex. S355J2G3

1 S= Structural Steel, E = Engineering steels without requirements for toughness and weldability

2) nnn = minimum yield Strength Reh (N/mm 2)

3) Impact Property
Testing Temperature = 20 deg. C , 27Joule = JR, 40Joule = KR
Testing Temperature = 0 deg. C , 27Joule = J0, 40Joule = K0
Testing Temperature = -20 deg. C , 27Joule = J2, 40Joule = K2

4) Symbols for special requirements
Deoxidation...G1= Rimming Steel,G2 =Rimming Steel not permitted,
Delivery conditions...G3 Normalised/ Normalised Rolled, G4 Manufactures Discretion.

EN 10027- Designation systems for steel.. Two systems available

EN10027-1
This is a designation system based on names. These names consist of alphanumerical characters and defines two main groups of steels
-steels designated on the basis of their use and their mechanical properties . e.g. S420ML designates a structural steel(S) with a specified yield strength of 420MPa(420) , thermochemically rolled (M) and with impact minimal value specified between +20 deg.C and -50 deg.C(L).
-steels designated on the basis of their chemical composition e.g. X2CrNi18-9 designates a stainless steel whose average contents in carbon, nickel and chromium are about 0.02%, 18% and 9% respectively.

EN10027-2
The other system is a numerical system. The steel numbers consist of 1 followed by a point and 4 figures. As and example the steels numbers of the above-mentioned steels are 1.8836 and 1.4307. The steel numbers are allocated by a European Registering Office. The registering authority has been given to VDEh in Dusseldorf.

EN 10028 - Flat products made of Steel for Pressure Purposes
EN 10113 - Hot-rolled products in fine grained structural steels

Steel Names according to form of ........X(1) nnn(2) X (3) Xn(4)....Ex. P265GH, P275NL1, S355NL, S355ML

1 S= Structural Steel, P = Steel for Pressure purposes

2) nnn = minimum yield Strength Reh (N/mm 2)

3) Condition
N = Normalised
G = Other Characteristic follows
M = Thermomechanically Rolled
4) Property
H = Elevated Temperature Property. Possible requirements for tensile test at high temperature.
L= Low temperature property, Impact testing at -10 Deg. C
L1= Low temperature property, Impact testing at -50 Deg. C
L2= Special low temperature property, Impact testing at -50 Deg. With enhanced requirements

EN10088 Stainless Steels

The three parts of EN 10088 were published in October 1995.

EN 10088-1 Stainless Steels -Part 1 : List of Stainless Steels (not for ordering)

Part 1 is a new idea, a reference list of 83 stainless steels, giving chemical composition, various physical properties, including density and a general description of the various classes of stainless steels. It is not intended for the direct placing of orders. The intention is that the steels required in the various steel product standards and application standards shall be selected from this list, as far as possible. They should not be defined slightly differently unintentionally,nor without a technical reason for different chemistry. Eventually the list in part 1 will be expanded to include corrosion resistant, hot oxidation resistant and creep resistant stainless steels, for general and pressure vessel use, with a cross-reference matrix showing which steels are in which standards, including the main application standards. At the moment there are frequent additions to this information.

EN 10088-2 Stainless Steels Part 2: Technical Delivery conditions for sheet/plate and strip for general purposes

This part of EN 10088 gives the properties and other delivery conditions for flat products for general purposes, i.e. not for pressure vessels nor for aerospace or other specialised applications, such as springs, It is used for ordering purposes. It contains 68 steels, more than BS1449:2 which it largely replaces.
It is based on a steel naming and numbering system, developed from the German Werkstoff system, which was the most suitable system available at the time the first EN standards were created.
Steel grades are classed as 'standard' or 'special' depending on how widely available they are, and how wide is their scope of application. 'Special' grades are likely to be more difficult to obtain, although the technical requirements are not different in kind between the two classes. There should be at least one grade listed, suitable for each general application. Mechanical properties are significantly more demanding than in BS 1449:2 but quite attainable in practice, with generally higher strength values, demonstrating the very useful properties of stainless steels.
Proof stress values at elevated temperatures are included and properties in the work hardened condition.

EN 10088-3 Stainless Steels -Part 3 Technical delivery conditions for semi-finished products, bars ,rods and sections for general purposes.

This is the corresponding standard for long products, but unlike BS970:1 which is replaces it does not cover forgings. Forgings are being covered in a separate standard being developed.

SELECTED STEELS

European Specn Code Yield Stress ReH Tensile Strength Rm Equivalent BS Code
- - Newton/mm2 Newton/mm2 - -
EN10025 S185 185 290-5102 - -
EN10025 S235JR 235 340-470 - -
EN10025 S235JRG2 235 340-470 BS4360 40B
EN10025 S235J0 235 340-470 BS4360 40C
EN10025 S235J2G3 235 340-470 BS4360 40D
EN10025 S275JR 275 410-560 BS4360 43B
EN10025 S275J0 275 410-560 BS4360 43C
EN10025 S275J2G3 275 410-560 BS4360 43D
EN10025 S355JR 355 490-630 BS4360 50B
EN10025 S355J0 355 490-630 BS4360 50C
EN10025 S355J2G3 355 490-630 BS4360 50D
EN10028 P235GH 235 360-480 BS1501 164-360
EN10028 P295GH 295 460-580 - -
EN10088 1.4512 220 380 BS1449-2 409S19
EN10088 1.4016 260 430 BS1449-2 430S17
EN10088 1.400 230 400 BS1449-2 403S17
EN10088 1.4006 - - BS1449-2 410S21
EN10088 1.4301 230 540 BS1449-2 304S31
EN10088 1.4307 220 520 BS1449-2 304S11
EN10088 1.4404 240 530 BS1449-2 316S11
EN10088 1.4541 220 520 BS1449-2 321S31
EN10088 1.4539 205 510 BS1449-2 310S24

    Relevant Steel Links

  1. British Stainless Steel Association Properties /Relevant Standards for Stainless Steels
  2. Dansk Steel WorksClick on Products > Standards for Information on European Steel Standards/properties

Home

Matter Index

Send Comments to RoyBeardmore@ic24.net

Last Updated 02/12/2000