Comparison of Steel Specifications
Steel standards are categorization, assessment, and specification systems for the chemical, mechanical, and metallurgical properties of different kinds of steels and ferrous alloys used in the production of components, equipment, and buildings. Steel standards assist metallurgical laboratories, manufacturers, and end-users in the manufacturing, processing, and use of steel.
Steels may be categorized by a wide range of parameters, including:
Carbon, low-alloy, or stainless steel make up the composition.
Method of production; basic oxygen process, electric arc furnace, etc.
Finishing processes, including cold or hot rolling and diverse surface finishing and plating techniques
Product Final; sheet, structural form, bar, wire, plate, and strip
Microstructure: ferritic, pearlitic, or martensitic Heat treatment: tempering, annealing, and quenching
However, there is no internationally recognized standard or classification system for steel. In its place, there are a number of accepted and extensively used categorization and identification systems that have been created and standardized either nationally and worldwide by Standards Development Organizations (SDOs) or by select vertical industries or suppliers.
The following are some of the most common steel categorization and standardization systems:
AISI-SAE (American Iron and Steel Institute – The Society of Automotive Engineers):
AISI-SAE steel categorization standards have been used in the United States and worldwide since 1941. In the AISI system, the steelmaking process is designated by a letter prefix. The prefix “C” is used to steels produced in an open-hearth furnace, electric arc furnace, or basic oxygen furnace, while the prefix “E” is applied to steels produced in an electric arc furnace. The presence of lead is indicated by the letter “L” in the grade name. Despite the fact that this standard is no longer maintained and has been substantially replaced by SAE, ASTM, and other American standards, it is still frequently used.
Euronorm (EN):
Euronorm (also known as the European Standard) is an international technical standard that has been adopted as applicable for a broad variety of commercial and industrial activities within the European Union. The standards may be identical to ISO or IEC global standards, have editorial or technical content alterations for European Union applicability, with amendments appended to the international standard, or be established by a European standards body. Despite being widely recognized and successful in many European countries, “obsolete” national systems like as the German DIN, British BS, French AFNOR, and Italian UNI are still commonly used and may be found in numerous documents and specifications.
JIS steel standards are extensively used across Asia and the Pacific. Other national systems, such as Korean, Chinese, and Taiwanese standards, have typically taken JIS steel criteria as a basis. The Japanese Industrial Standard (JIS) categorizes steel material numbers into two types:
-
Structural Steel:
The material designation is same to that of CNS. Example: S30C indicates structural steel containing 0.30 percent carbon.
- Other applications for carbon and alloy steels:
This kind of material code consists of three sections. The first portion indicates substance. The second component specifies the steel’s application or specification, while the third component identifies the material kind.
ASTM stands for the American Society for Testing and Materials/American Society of Mechanical Engineers (ASME)
Steel standards from ASTM are used to classify, evaluate, and specify the material, chemical, mechanical, and metallurgical properties of various types of steels, which are mainly used in the manufacturing of mechanical components, industrial parts, and construction elements, as well as many other associated equipment. Options include carbon, structural, stainless, ferritic, austenitic, and alloy steels. These steel standards aid metallurgical labs and refineries, product manufacturers, and other end-users of steel and its variants in guaranteeing the quality and safety of its utilization via suitable processing and application methods. The ASTM standard is a frequently used material specification that focuses on the characteristics and performance of products.
Deutsches Institut fur Normung e.V (DIN)
DIN used to stand for Deutsch Industrienorm (German Industry Standard), but it now stands for Deutsches Institut für Normung. In 1974, the International Organization for Standardization revised this standard with Euronorm 27-74. Letters and numbers are employed to categorize objects. The letters represent the steel type, smelting method, alloy materials, and processing condition, whilst the numbers represent the steel material, carbon content, tensile strength, and element fixed-point number of the primary alloy.
Other Steel Specifications
Steel standards from newly industrialized countries, such as the Chinese GB and YB, the Indian IS, and the Brazilian NBR, are today recognized owing to global procurement, although often being less developed and exhaustive. The same may be stated about Russian GOST, the de facto norm for the whole Commonwealth of Independent States.
Vertical industrial steel standards include SAE for automotive, aerospace and more; ASME for pressure vessels and many other uses; AWS for welding consumables and associated materials. The American ABS, the British Lloyds, the Italian RINA, and others cover shipbuilding requirements.
In addition to the several standards described above, many steel makers and suppliers have devised their own commercial designations for identifying steels. After years and decades of use, a number of these identities have grown pervasive in the business sector and are usually referred to as common names or trade names without really identifying the source. Because these “common” names are seldom standardized and their properties might vary widely, they should not be used in official technical papers.