Steels can be classified by a large variety of criteria, such as:
- Composition, for example carbon, low-alloy, or stainless steel
- Method of manufacturing, such as open hearth, basic oxygen process, or electric furnace methods
- Finishing method, such as hot rolling, cold rolling, and various surface finishing and platting techniques
- Product form, for example bar, wire, plate, sheet, strip, tubing or structural shape
- Deoxidation practice, such as killed, semi-killed, capped or rimmed steel
- Microstructure, such as ferritic, pearlitic and martensitic
- Heat treatment, such as annealing, quenching and tempering.
Unfortunately, there is no common global steel standard or classification system. Rather, there are a number of classification and designation systems accepted and used worldwide, which are developed and standardized either nationally and internationally by Standard Development Organizations (SDOs), or by specific vertical industries or suppliers. Some of the more frequently used steel standard and classification systems include:
- AISI (American Iron and Steel Institute) steel standards, which are traditionally used in the US and abroad. While this standard is no longer maintained and has increasingly been replaced by SAE, ASTM and other U.S. standards, it is still widespread.
- EN (Euronorm), which is a harmonized system of metal and steel standards of European countries. Although it is accepted and effectively used in all European countries, “obsolete” national systems, such as German DIN, British BS, French AFNOR and Italian UNI are commonly used and often found in many documents and specifications.
- Japanese JIS steel standards, which are widely used in Asia and Pacific regions. JIS steel specifications have also often been used as a base for other national systems, such as Korean, Chinese, and Taiwanese standards.
- Steel standards of newly industrial countries, such as Chinese GB and YB, Indian IS, and Brazilian NBR, although sometimes less developed and detailed, are increasingly being used due to global sourcing. The same applies for Russian GOST, which is practically the de facto standard for the whole Community of Independent States.
Vertical industrial steel standards include SAE for automotive, aerospace and
more; ASME for pressure vessels and many other applications; AWS for welding
consumables and related materials. Shipbuilding specifications are covered by
the American ABS, British Lloyds, Italian RINA and others.
In addition to the many standards described above, many steel manufacturers
and suppliers have developed their own proprietary, commercial names for
designating steels. Some of these designations have, after years and decades of
use, become widely used within the industrial community and are often referred to as “common“ names or “trade” names, without actually referring to the
particular supplier. In most cases, these “common” names are not standardized
and properties may vary substantially; their application in official technical
documents should therefore be avoided.
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the mechanical properties, chemical composition, cross-reference tables, and
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