Heat treated alloy structural steel and alloy spring steel

Use two Arabic numerals to indicate the average carbon content (in parts per million) and place it at the head of the brand.

The expression method of alloy element content is as follows: when the average content is less than 1.50%, only the element is indicated in the brand, and the content is not generally indicated. The average alloy content is 1.50% ~ 2.49%, 2.50% ~ 3.49%, 3.50% ~ 4.49%, 4.50% ~ 5.49%... Is written as 2, 3, 4, 5...... .

For example, the average content of carbon, chromium, manganese and silicon is 0.30%, 0.95%, 0.85% and 1.05% respectively. Alloy structural steels with average contents of carbon, chromium and nickel of 0.20%, 0.75% and 2.95%, respectively, are labeled "20CrNi3".

High quality alloy structural steel, marked "A" at the end of the grade. For example "30 crmnsia". Special grade high quality alloy structural steel, with the symbol "E" at the end of the brand, for example: "30CrMnSiE".

Special alloy structural steel, with a symbol representing the product use as specified in table 1-1 at the head (or tail) of the brand. For example: rivet screw steel with the average content of carbon, chromium, manganese and silicon of 0.30%, 0.95%, 0.85% and 1.05% respectively, whose brand name is "ML30CrMnSi".

The representation method of alloy spring steel is the same as that of alloy structural steel. For example, spring steel whose average content of carbon, silicon and manganese is 0.60%, 1.75% and 0.75% respectively, its brand name is "60Si2Mn". High quality spring steel, at the end of the brand with the symbol "A", the brand is represented as "60Si2MnA".