The number of the raw material of the iron strap

The classification of the numbered steel of the raw material of the iron strapping belt can only divide and summarize the steel grades with common characteristics into the same category, and it is impossible to reflect all the characteristics of each steel. Therefore, in order to reflect the characteristics of each type of steel, a unified numbering method must be developed. This numbering method should be concise and easy to remember. my country has stipulated a unified method of expression, that is, all the characteristics of each type of steel are expressed by symbols. This method stipulates: the alloying elements in steel are expressed by international chemical symbols or Chinese characters, such as 'chromium' or 'Cr' 'Silicon' or 'SiProduct use, smelting and pouring methods are expressed in Chinese characters and Chinese pinyin letters, and abbreviations are generally used. The carbon content and the content of alloying elements are expressed in numbers. The carbon content of structural steel is in units of 0.1%. For example, for steels with an average carbon content of .%, .%, and .%, the steel grades should be 'The carbon content of tool steel is in units of 0.1%. For example, for a carbon tool steel with an average carbon content of .%, the corresponding steel grade is 'T'. The carbon content is written at the top of the symbol (the alloy tool steel with carbon content equal to or greater than% may not be marked), and the content of alloy elements is written after the letter of the element. For steels with higher manganese content, the manganese element should be marked. For example: steel with carbon content of .% and manganese content of .% to .%, the corresponding steel grade is 'Mn'. High-grade high-quality steel with low sulfur and phosphorus content is indicated by adding the letter 'A' at the end of the steel number. At the same time, in order to indicate the use of steel, a use label is attached before certain steel grades. Usually, 'T' is added to carbon tool steel, and 'G' is added to ball bearing steel.