4Cr9Si2 mainly for the manufacture of boilers, turbines, power machinery, industrial furnaces and aerospace, petrochemical and other industrial sectors to work in high temperature components. In addition to these components requires high temperature strength and high temperature oxidation corrosion, according to different purposes also requires a sufficient toughness, good processability and welding, as well as certain organizational stability. Since 1952, China began to produce heat-resistant steel. After the development of some new type of low-alloy steel, hot and strong, so strong pearlite steel operating temperature heat to 600 ~ 620 ℃; In addition, the development of some new low-chromium-nickel steel oxidation.

Features:
Work-study have a higher thermal resistance for the internal combustion engine intake valve, exhaust valve engine light load and so on.

Chemical composition:
Carbon C: 0.35 ~ 0.50
Si Si: 2.00 ~ 3.00
  Manganese Mn: ≤ 0.70
  Sulfur S: ≤ 0.030
  Phosphorus P: ≤ 0.035
  Chromium Cr: 8.00 ~ 10.00
  Ni-Ni: ≤ 0.60

Mechanical properties:
Tensile strength σb (MPa): quenching and tempering, ≥ 885
  Conditions yield strength σ0.2 (MPa): quenching and tempering, ≥ 590
  Elongation δ5 (%): quenching and tempering, ≥ 19
  Reduction of area ψ (%): quenching and tempering, ≥ 50
  Hardness: Annealed, ≤ 269

Heat treatment:
1) quenching, 1020 ~ 1040 ℃ oil cooling;
  2) tempering, 700 ~ 780 ℃ oil cooling.