1、 Overview of Steel Grade Representation Methods in China

The steel grade, abbreviated as steel grade, is the name given to each specific steel product and a common language for people to understand steel. The representation method for steel grades in China is based on the national standard "Method for the Representation of Steel Product Grades" (GB221-79), which uses a combination of Chinese pinyin letters, chemical element symbols, and Arabic numerals. Namely:

① The chemical elements in the steel grade are represented by international chemical symbols, such as Si, Mn, Cr, etc. Mixed rare earth elements are represented by "RE" (or "Xt").

② The product name, purpose, smelting and pouring method, etc. are generally represented by abbreviated letters in Chinese Pinyin, as shown in the table.

③ The main chemical element content (%) in steel is expressed in Arabic numerals.

3、 Comparison of some new and old steel grades

1. Comparison of new and old standard steel grades for carbon bonded steel.

The new standard GB700-88 refers to the international standard ISO630 "Structural Steel", while the old standard GB700-79 mainly refers to the former Soviet Union IOCT380. Therefore, the steel grade representation methods and technical requirements for each steel grade are different between the two.

2. Low alloy steel is currently using GB/T1591-94 instead of 1591-88