commonly used metal material grades

Commonly used metal material grades

Machinery parts are used in a variety of metal materials, in order to make production, management, convenient, orderly, the relevant standards for different metal materials to specify their grades of representation, in order to show unity and facilitate the adoption, use.

Iron and steel product grades ( refer to GB/T221-2000)

Basic overview of the standard

GB/T221-2000 standard is a reference to the foreign steel product grade representation and domestic steel product grade representation changes (such as Q345 instead of 16Mn) and other revisions, issued on April 1, 2000, and November 1, 2000, the implementation.

Main technical content changes

(1) Since some steel products have their own special standards, the original standards for iron alloys, casting alloys, high-temperature alloys, precision alloys, corrosion-resistant alloys and cast iron, cast steel, powder materials, etc. were eliminated.

(2) The emergence of some new steel products, more perfect than the original standard. The new standard increases the decarburized low phosphorus grain iron, vanadium pig iron, casting wear-resistant pig iron, to ensure that the hardenability of steel, non-quenched mechanical structural steel, plastic mold steel, oriented silicon steel ( telecommunications ), and other grades indicate the method.

(3) does not adapt to the development of science and technology and the production of some steel grades is not coordinated to make a complete change or modify. Such as carbon structural steel A3 to Q235, low-alloy high-strength structural steel 16Mn to Q345, etc. Stainless steel, heat-resistant steel, and cold-rolled silicon steel, such as the number of the method of expression have also been modified.

(4) The original standard “steel product grade representation examples” of Table 3, as not applicable to the new standard was deleted.

Commonly Used Metal Material Grades

Basic Principles of Steel Product Grades

(1) Where the national standards and industry standards in the steel product grades should be prepared in accordance with the GB/T221-2000 standard grade representation. Where not in line with the provisions of the preparation of steel product grades, should be changed in the revision of the standard, some new steel products, their grades should also be prepared in accordance with this grade.

(2) the product grade, generally using the Hanyu pinyin alphabet, chemical element symbols, and Arabic numerals combined to indicate the method.

(3) the use of Hanyu pinyin letters to indicate the product name, use, characteristics, and process methods, generally from the representative of the product name in Hanyu pinyin selected the first letter. When the letter chosen is repeated with another product, the second or third letter can be used instead, or the first letter of the Hanyu pinyin in two Chinese characters can be chosen at the same time.

(4) temporarily no Chinese characters and Hanyu pinyin can be used, using the symbol for the English alphabet.