Material Name: spring steel
Grade: 30W4Cr2VA
30w4cr2va Introduction
Standard: GB / T 1222-1984
● Features and application:
As the role of tungsten chromium vanadium, this steel has a good warm room temperature mechanical properties and extraordinary high hardenability, tempering good stability, good thermal processing performance. Used in the quenched state, as the working temperature ≤ 500 ℃ heat below the spring, the main valve spring, such as boiler, turbine steam seal springs and so on.
Chemical composition
● Chemical Composition:
Carbon C: 0.26 ~ 0.34
Si Si: 0.17 ~ 0.37
Manganese Mn: ≤ 0.40
Sulfur S: ≤ 0.030 P P: ≤ 0.030
Chromium Cr: 2.00 ~ 2.50
Ni-Ni: ≤ 0.35
Copper Cu: ≤ 0.25
Vanadium V: 0.50 ~ 0.80
Tungsten W: 4.0 ~ 4.5
● Mechanical Properties:
Tensile strength σb (MPa): ≥ 1470 (150) '
Conditions yield strength σ0.2 (MPa): ≥ 1323 (135)
Elongation δ5 (%): ≥ 7
Reduction of area ψ (%): ≥ 40
Hardness: hot heat, ≤ 321HB; cold drawing heat treatment, ≤ 321HB
Note: In addition to tensile strength, the other performance parameters of the test results for reference
Sample size:,
● Heat treatment and microstructure specifications:
Standard heat treatment: quenching 1050 ~ 1100 ℃, oil cooling; tempering 600 ℃ ± 50 ℃ (extraordinary need, ± 30 ℃).
● Delivery status: hot-rolled steel to heat treatment or heat treatment delivery, cold-drawn steel with heat treatment delivery.
30w4cr2va representation
① steel beginning of the two numbers indicate the carbon content of steel, the average carbon content of the very few that, as 40Cr, 25Cr2MoVA alloy steel tube ② main alloying elements, except for a few micro-alloying elements, in general, to a few percent said. When the average alloy content <1.5%, the steel elements generally marked only symbols, but not marked content, but prone to cause confusion in those special circumstances, after the element symbol can also be marked with the number "1", such as steel "12CrMoV" and "12Cr1MoV", the former chromium content of 0.4-0.6%, 0.9-1.2% for the latter, all the remaining ingredients the same. When the average content of alloying elements ≥ 1.5%, ≥ 2.5%, ≥ 3.5% ... ... when, after the element symbol should be marked content, can be expressed as the corresponding 2,3,4 ... etc. For example 18Cr2Ni4WA.
③ vanadium steel V, Ti Ti, Al AL, boron B, and other rare earth RE alloying elements, are micro-alloying elements, although the content is very low, should bid out in steel. For example 20MnVB steel. To 0.07-0.12% vanadium, boron is 0.001-0.005%.
④ High quality steel should be added in the last steel "A", as distinct from the general high quality steel.
⑤ special purpose alloy structural steel, steel, known (or suffix) represents the symbol of the use of steel. For example, rivet screw special 30CrMnSi steel, steel, said to ML30CrMnSi.
