Designation
| Name |
The value |
| Designation GOST Cyrillic |
25НЛ |
| Designation GOST Latin |
25HL |
| Transliteration |
25NL |
| By chemical elements |
25Н |
Description
25НЛ steel is used: for the manufacture of casting parts for gas turbines and axial compressors operating at temperatures from -70 to +350 °C.
Note
Steel pearlitic class.
Standards
| Name |
Code |
Standards |
| Steel castings |
В82 |
OST 108.961.04-80 |
Chemical composition
| Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
| OST 108.961.04-80 |
0.22-0.3 |
≤0.025 |
≤0.025 |
0.5-0.8 |
≤0.3 |
0.17-0.37 |
0.7-1.2 |
Rest |
≤0.3 |
Fe is the basis.
According to OST 108.961.04-80, the total sulfur and phosphorus content should be ≤ 0.050% for all possible tolerances.
Mechanical properties
| sT|s0,2, MPa |
σU, MPa |
d5, % |
y, % |
KCU, kJ/m2 |
| Casting parts of gas turbines. Annealing at 850-870 °C, cooling with furnace + quenching in oil with 860-880 °C + vacation at 640-670 °C, cooling with the furnace to 300 °C |
| ≥245 |
≥441 |
≥19 |
≥30 |
≥390 |
Description mechanical marks
| Name |
Description |
| sT|s0,2 |
Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2% |
| σU |
Limit short-term strength |
| d5 |
Elongation after rupture |
| y |
The relative narrowing |
| KCU |
Toughness |
