The capital letter DR after the steel number stands for "hot rolled silicon steel for electrical use" DR- electric heating.
The lowercase letter G after the steel number stands for "boiler steel" G-pot.
Naming rules for steel grades: It consists of Q+ number+quality grade symbol+deoxidation method symbol. Steel grade generally uses "Q" to indicate the yield point of steel, and the following number indicates the yield point value, in MPa. For example, Q235 indicates that the yield point is
235? MPa carbon structural steel. When necessary, symbols indicating quality grade and deoxidation method can be marked behind the steel number. The quality grade symbols are a, b, c and d respectively. Deoxidation mode symbol: F stands for boiling steel, B stands for semi-killed steel, and Z stands for killed steel; TZ stands for special killed steel, and killed steel can be left unmarked, that is, Z and TZ can be left unmarked.
For example, Q235-AF stands for Class A boiling steel.
Carbon steel for general special purposes such as bridge steel and marine steel is basically represented by carbon structural steel.