Wallid Guergour
metallurgy
25/12/2021
The European standard EN 10027 groups the "steel designation systems", thus replacing the standard NF A 02 005
The European standard EN 10027 groups the "steel designation systems", thus replacing the standard NF A 02 005. There are two European systems for designating a standardised steel (French designations are still allowed). Symbolic designation: this is based on literal and numerical symbols and comprises two groups. Group 1: The designation of steels in this group refers to the use and the mechanical or physical characteristics of the designated steel. Group 2: The designation of steels in this group refers to the chemical composition. Numerical designation: complementary to the symbolic designation, it assigns to each steel grade a characteristic number comprising 5 digits between 10 000 and 19 999.
2. Steels designated according to their use and their mechanical or physical characteristics or physical characteristics
The designation includes : - The letter G if specified in the form of a casting, the letters PM if produced the letters PM if produced by powder metallurgy. - A letter : S (Structure) for structural steel. P for steels intended for the manufacture of pressure vessels. L for steels intended for the manufacture of pipes. E (Engine) for engineering steel. B for concrete reinforcing steels. Y for pre-stressed concrete steels. R for steels for the manufacture of rails or in the form of rails. D for cold-forming flat steels H for high strength cold forming flat steels. T for packaging steels (black iron*, tinplate, chrome iron) M for electrical steels - A number that expresses the minimum yield strength in N/mm2 (MPa - 3 digits in general). - A specification expressed by a letter or a number and a letter if there is a specific quality.
| A | B | C | D | E | F | |
|---|---|---|---|---|---|---|
1 | 1 | 2 | 3 | |||
2 | G E n n n | an ........................... | an............... | |||
3 | main symbols | additional symbols | ||||
4 | letter | mechanical characteristic | for steel products | |||
5 | Group 1 | Group 2 | ||||
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7 | G = cast steel E = structural steel mechanical | nnn = specified minimum value of yield strength (B) in MPa (C) for the lowest thickness range | other characteristics followed, if necessary, by 1 or 2 digits or if impact resistance characteristics are specified, the rules of Group 1 of Table 1 shall apply. | C = for cold drawing | ||
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19 | sub-group 1 | sub-group 2 | ||||
20 | breaking energy | test temperature °c | C | special cold forming | ||
21 | D | galvanising | ||||
22 | 27 40 50 | E | enamelling | |||
23 | JR KR LR | 20 | F | forging | ||
24 | JO KO LO | 0 | H | hollow profile | ||
25 | J2 K2 L2 | -20 | L | low temperature | ||
26 | J3 K3 L3 | -30 | M | thermomechanical forming | ||
27 | J4 K4 L4 | -40 | N | normalized or normalizing rolling | ||
28 | J5 K5 L5 | -50 | O | offshore | ||
29 | J6 K6 L6 | -60 | Q | hardened and tempered | ||
30 | M = thermomechanical rolling N = normalised or normalising rolling Q = quenched and tempered G = other characteristics followed, where necessary, by 1 or 2 digits | S | shipbuilding | |||
31 | T | tubes | ||||
32 | W | resistant to atmospheric corrosion | ||||
33 | an | chemical symbol of the specified alloying element, e.g. Cu, possibly with a single digit representing 10 times the average (rounded to 0.1%) of the specified range of the content of this element. | ||||
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37 | Exemple : | |||||
38 | Construction steel | |||||
39 | S 235 JO | RE > 235 MPa | ||||
40 | Kv0°C ⩾ 27J | |||||
41 | symbols for special requirements (1) | |||||
42 | Symbol | Signification | ||||
43 | ,+ C (2) | Coarse grain | ||||
44 | ,+ F | Fine grain | ||||
45 | ,+ H | Tempered | ||||
46 | ,+ Z15 | Guaranteed property in the direction of thickness: minimum stricture = 15%. | ||||
47 | ,+ Z25 | Guaranteed property in the direction of thickness: minimum stricture = 25%. | ||||
48 | ,+ Z35 | Guaranteed property in the direction of thickness: minimum stricture = 35%. | ||||
49 | (1) These special requirements are normally characteristics of the steel. For practical reasons, they are used as symbols for steel products. (2) The (+) sign separates from the previous symbol. | |||||
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53 | symbols for type of coating | |||||
54 | ,+ A (1) | Hot-dip aluminizing | ,+ S | Hot dip tin coating | ||
55 | ,+ AR | Aluminium cladding by plating | ,+ SE | Electrolytic tin coating | ||
56 | ,+ AS | Aluminium-silicon alloy coating | ,+ T | Hot-dip lead-tin alloy coating | ||
57 | ,+ AZ | Zinc-aluminium alloy coating (>50% AL) | ,+ TE | Electrolytic lead-tin alloy coating | ||
58 | ,+ CE | Electrolytic chromium/chromium oxide coating | ,+ Z | Hot dip zinc coating | ||
59 | ,+ CU | Copper coating | ,+ ZA | Zinc-aluminium (>50% Zn) hot dip coating | ||
60 | ,+ IC | Inorganic coating | ,+ ZE | Electrolytic zinc coating | ||
61 | ,+ OC | Organic coating | ,+ ZF | Hot dip zinc-iron coating | ||
62 | (1) the (+) sign separates from the previous symbol | |||||
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64 | symbols for type of treatment | |||||
65 | ,+ A (1) | Softening annealing | ,+ NT | Normalized and income | ||
66 | ,+ AC | Carbide globulating annealer | ,+ Q | Tempered | ||
67 | ,+ AT | Solution annealing | ,+ QA | Air quenched | ||
68 | ,+ C | Cold worked | ,+ QO | Oil quenched | ||
69 | ,+ CR | Cold rolled | ,+ QT | Quenched and tempered | ||
70 | ,+ HR | Hot rolled and cold worked | ,+ QW | Water quenched | ||
71 | ,+ LC | Skin pass | ,+ S | Cold shearing treatment | ||
72 | ,+ M | Thermomechanical forming | ,+ T | Tempering | ||
73 | ,+ N | Normalised or normalising forming | ,+ U | Untreated | ||
74 | (1) the (+) sign separates from the previous symbol, To avoid confusion, the letter S can be used as a prefix to these symbols (+SA). | |||||
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. Steel Technics. French Alps.