The method of marking the number of common metal materials (three)
Indication method of alloy structural steel and alloy spring steel
- the alloy structural steel grades are represented by the Arabia digital and standard chemical element symbols
Two digit Arabia figures were used to indicate the average carbon content (a few thousandths of the total) and placed on the brand head. The method of alloy element content is as follows: when the average content is less than 1.50%, only the elements are identified in the grades, and the contents are generally not marked. The average alloy content is 1.50% ~ 2.49%, 2.50% ~ 3.49%, 3.50% ~ 4.49%, 4.50% ~ 5.49%,... At the time of the alloying elements, they are written in 2, 3, 4, 5... For example: the average content of carbon, chromium, manganese and silicon are respectively 0.30%, 0.95%, alloy structural steel, 0.85%, 1.05%, when S and P concentrations were less than 0.035%, the grade is expressed as "30CrMnSi". High quality alloy structural steel (S, P concentrations were less than 0.025%), said in the rear plus grade symbol "A". For example, "30 CrMnSiA". Super high grade alloy steel (S = 0.015%, P = 0.025%), in the rear plus symbol grade "E", for example: "30CrM nSiE".
The brand of special alloy structural steel should still be added to the mark on the head (or tail) to represent the use of the product.
The expression of the grade of alloy spring steel is the same as that of alloy structure steel
For example, the average content of carbon, silicon, and manganese is 0.60%, 1.75%, 0.75% of the spring steel, whose brand name is "60Si2Mn". High quality spring steel, with the symbol "A" at the end of the brand, the brand name is "60Si2MnA".
The method of indicating the grade of the easy cutting steel
The easy cutting steel is represented by the symbol of standard chemical elements, the symbols specified in Table 1 and the number of Arabia figures. The Arabia figures show the average carbon content (by a few thousandths).
A, sulphur free cutting steel and sulfur and phosphorus free cutting steel, without the symbol of easy cutting element after the symbol "Y" and the Arabia number. For example, the average carbon content is 0.15% of the easy cutting steel, the brand name is "Y15".
B, high manganese content of sulfur or sulfur, phosphorus free cutting steel in the symbol "Y" and Arabia number after adding manganese element symbols. For example, the average carbon content of 0.40%, manganese content from 1.20% to 1.55% of the easy cutting steel, its brand name is "Y40Mn".
C, easy cutting steel with easy cutting elements such as calcium and lead, added to the symbol "Y" and Arabia digits. For example, "Y15Pb", "Y45Ca".
- mechanical structure of non quenched and tempered steel grades that the method of mechanical structure of non quenched and tempered steel, respectively in the head grade symbol "YF" and "F" that the easy cutting non quenched and tempered steel with non mechanical structure and mechanical structure of steel and hot forging, designation of other content and the same alloy structural steel. For example, "YF35V", "F45V".
