What are the material numbers and their designation system according to DIN EN 10027-2?
The EN material numbers are used for the unique designation of a material. As a rule, they have a five-digit structure.
Unless otherwise agreed, stainless steel 1.4571 (ASTM designation 316Ti) is used as the factory standard at ACI Industriearmaturen GmbH, therefore we consider this chemically highly resistant stainless steel as an example.
1.4571(+AT)
1. | 45 | 71 | Material main group |
1. | 45 | 71 | Steel group number |
1. | 45 | 71 | Steel grade number |
+AT | Additional symbols (mostly heat treatment or surface condition) |
The main material group is separated from the steel group number and the steel grade number by a dot. In general, the material number provides information about the chemical composition, the technological characteristics, the heat treatment condition or the surface quality of a metallic material. These characteristic values are determined according to standardised test procedures.
Below we take a look at the breakdown using a stainless steel 1.4571 as an example.
1. | Steel or cast steel | |
45 | Stainless steels with special additives | |
71 | Within a steel group, each grade is given its own count number | |
+AT | Heat treatment as delivered: Solution annealed |
The material abbreviation provides further information. For 1.4571 this is:
X6CrNiMoTi 17-12-2
X | means a high-alloy steel in which the content of at least one alloying element is more than 5%. | For high-alloy steels, the mass fraction of the alloying elements must always be multiplied by 1. (Exception: carbon) |
6 | Carbon content: | 6/100 = 0.06% (The mass fraction for carbon is always divided by 100) |
Cr | Mass fraction of Chromium: | 17% |
Ni | Mass fraction of Nickel: | 12% |
Mo | Mass fraction of Molybdenum: | 2% |
Ti | Mass fraction of Titanium: | 6/100 = 0.06% (The mass fraction for carbon is always divided by 100) |
