The Classification Of Steel
The main elements in addition to iron, carbon steel, silicon, manganese, sulfur, phosphorus, etc.
Steel classification method is varied, the main method has the following seven:
1.According to the quality of classification
(1) ordinary steel (Ps0.045%, Ss0.050%)
(2) the high quality steel (P, S < 0.035%),
(3) high quality steel (Ss0.030 Ps0.035%, %)
The classified by chemical composition
(1) carbon steel:
a. Low carbon steel (C < 0.25%).
b. medium carbon steel (C < ~ 0.250.60%).
c. high carbon steel (C < 0.60%)
(2) alloy steel:
a. low alloy steel (alloy element total content < 5%).
b. in alloy steel (alloy element total content > 5 ~ 10%);
c. high alloy steel (alloy element total content >10%)
2.According to the forming method of classification
(1) forging steel;
(2) cast steel;
(3) hot rolled steel,
(4) cold-drawn steel.
3.According to the microstructure classification
(1) annealing state:
A. hypoeutectoid steel (ferrite + pearlite);
B. eutectoid steel (pearlite);
C. hypereutectoid steel (pearlite and cementite);
D. ledeburite steel (pearlite and cementite)
(2) the state of the fire:
A. pearlitic steel;
B. bainite steel;
C. martensitic steel;
D. austenitic steel.
(3) without phase change or part of a phase change
4.Microstructure classification
(1) annealing state:
A. hypoeutectoid steel (ferrite + pearlite);
B. eutectoid steel (pearlite);
C. hypereutectoid steel (pearlite and cementite);
D. ledeburite steel (pearlite and cementite).
(2) the state of the fire: A. pearlitic steel;
B. bainite steel;
C. martensitic steel;
D. austenitic steel.
(3) without phase change or part of a phase change
5. According to the classification purpose
(1) construction and engineering steel:
A. ordinary carbon structural steel; B. low alloy structural steel; C. reinforced steel.
(2) structural steel:
A. machinery manufacturing steel quenched and tempered steels:
(a) quenched and tempered steel;
(b) surface hardening steel: including carburizing steel, permeability of ammonia steel, surface quenching steel;
(c) free cutting steel;
(d) cold plastic forming steel: including cold-formed steel, LengHui steel.
B. spring steel
C. bearing steel
(3) tool steel: A. carbon tool steel;
B. alloy tool steel;
C. high speed tool steels
(4) the special performance of steel: A. acid-proof stainless steel; B. heat resistant steel, including oxidation heat intensity steel, steel, steel valve;
C. electrothermal alloy steel;
D. wear resistant steel;
E. cryogenic steel;
F.electrical steel.
(5) professional steel: such as Bridges with steel, ship steel, boiler steel, pressure vessel steel, agricultural machinery, steel, etc.
6. Comprehensive classification
(1) ordinary steel
A. arbon structural steel:
(a) Q195.
(b) Q215(A, B);
(c) Q235 (A, B,C);
(d) Q255 (A, B);
(e) Q275o
B. low alloy structural steel
C. specific use of common structural steel
(2) the high quality steel (including advanced high-quality steel)
7. According to the smelting method classification
(1) according to the furnace
A. converter steel:
(a) Bessemer steel;
(b) basic Bessemer steel.
Or (a) converter steel;
(b) side blown converter steel;
(c) ld converter steel.
B. electric steel:
(a) electric arc furnace steel;
(b) electroslag furnace steel;
(c) induction furnace steel.
(d) vacuum self-consuming furnace steel;
(e) electron beam furnace steel.
(2) According to the degree of deoxidation and pouring system,
A. boiling steel;
B. semi-calm steel;
C. calm steel;
D. special calming steel.