Werkstoffnummer
 according to DIN EN 10027-2

Material designation is a systematic and standardized method for identifying the specific properties of a material. This is particularly important in the metal industry, where there are a wide variety of materials that can vary greatly in composition and properties.
A material designation for steel, for example, provides information about the chemical composition, mechanical properties, and often also about the heat treatment of the steel.

A German material number, also known as a DIN EN Werkstoffnummer, is a five-digit number that is standardized in DIN EN 10027-2. It is unique and enables uniform identification of the material worldwide. Extended counting numbers that are listed from time to time are not generally used.

• Material group: The first digits of the material number provide information about the material group. For example, the digits 1.4 stand for stainless steels.
• Chemical composition: The following numbers provide information about the chemical composition of the steel. They can indicate, for example, the carbon content or the presence of certain alloying elements.
• Condition symbols: Any letters appended may provide information about the heat treatment (e.g., “H” for hardened) or the mechanical properties (e.g., “Q” for quenched and tempered) of the steel.

An example of such a designation is “1.4301.” Here, the “1” stands for iron-based alloys, the “.4” for stainless steels, and the ‘301’ for the specific chemical composition of this steel, in this case a certain type of stainless steel (also known as “Edelstahl”).

It is important to understand that the material designation only provides an overview of the basic properties of the steel. For more detailed information, such as exact values for tensile strength, elongation, or hardness, refer to the manufacturer's material data sheet.

Knowledge of material designations is an essential tool for engineers, technicians, and anyone involved in the selection and processing of steel and other metals. It enables accurate identification of the material and helps to make the best choice for a specific application.

Comparison Table ANSI/ASTM /DIN

Some interesting facts

Duplex steels

Duplex steel refers to materials that have a two-phase structure (ferrite and austenite). Duplex steels are characterized by their combination of properties, which represent a mixture of the properties of stainless chromium steels (ferritic or martensitic) and stainless chromium-nickel steels (austenitic).

They have higher strengths than stainless chromium-nickel steels, but exhibit higher ductility than stainless chromium steels. Unlike pure austenites, they still exhibit fatigue strength when subjected to alternating stresses up to an austenite content of approx. 40%. Duplex steels are classified as rust- and acid-resistant steels.

Pitting Resistance Equivalent Number (PREN) index

The PREN index is a measure of the corrosion resistance of stainless steel. ASTM G48 specifies the test methods for this.

In corrosion-resistant steels, the chemical elements that are decisive for corrosion behavior are summarized by the PREN, which establishes a relationship between pitting resistance and chemical composition.

• PREN = %Cr + 3.3 x %Mo (ferritic steels)
• PREN = %Cr + 3.3 x %Mo + 16 x %N (austenitic steels)
• PREN = %Cr + 3.3 x %Mo + 30 x %N (duplex steels)

Ferritic-austenitic duplex steels with PREN 40 are also referred to as super duplex steels and are characterized by particularly high corrosion resistance. Steels with PREN values above 32 are considered saltwater resistant.

Weldability of steels

Steels with a carbon content of more than 0.22% are only considered to be conditionally weldable; additional measures such as preheating are required. However, the carbon content of the steel alone does not determine its weldability, as this is also influenced by many other alloying elements. The so-called carbon equivalent is therefore taken into account for assessment purposes.

In materials science, the carbon equivalent is a measure used to assess the weldability of unalloyed and low-alloy steels. The carbon content and a variety of other alloying elements in steel influence its behavior. To assess weldability, the carbon content and the weighted proportion of elements that influence the weldability of the steel in a similar way to carbon are therefore combined into a numerical value in the carbon equivalent. A carbon equivalent value of less than 0.45% implies good weldability. Higher values require the material to be preheated, depending on the processing thickness. Above a value of 0.65, the workpiece is only weldable with increased effort, as martensite formation can lead to cold or hardening cracks.

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