Steel 15X28
Steel 15X28
Steel 15Kh28: a classifier of steels and alloys. Below is systematized information on the purpose, chemical composition, types of supply, substitutes, critical point temperature, physical, mechanical, technological and foundry properties for the grade - Steel 15X28.
General information on steel 15X28
| The substitute for the following grades |
| Steel grade: 15Kh25T, 20Х23Н18. |
| Delivery type |
| Bar stock, including shaped: GOST 5949−75, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated rod GOST 7417−75, GOST 8559−75, GOST 8560−78. Grinded rod and silver GOST 14955−77. Sheet thin GOST 5582−75. Strip GOST 4405−75, GOST 103−76. Forgings and forged blanks GOST 1133−71. GOST 9940−81 pipes. |
| Application |
| Welded structures not exposed to impact loads at operating temperature not lower than -20°С; junctions with glass. Apparatus, parts, tubes of pyrolysis units, heat exchangers. Pipes for heat-exchange equipment operating in aggressive environments. Heat-resistant corrosion-resistant steel of ferrite class. |
Chemical composition of steel 15Х28
| Chemical element | % |
| Silicon (Si), not more | 1.0 |
| Manganese (Mn), not more than | 0.8 |
| Copper (Cu), not more than | 0.30 |
| Nickel (Ni), not more than | 0.60 |
| Sulfur (S), not more than | 0.025 |
| Titanium (Ti), not more than | 0.2 |
| Carbon ©, not more than | 0.15 |
| Phosphorus (P), not more than | 0.035 |
| Chromium (Cr) | 27.0−30.0 |
Mechanical properties of steel 15X28
| Heat treatment, delivery condition | Section, mm | σ0, 2, MPa | σB, MPa | δ5, % | ψ, % |
| Rods. Annealed at 680−720°C, air or water or without heat treatment | 60 | 295 | 440 | 20 | 45 |
| Hot- or cold-rolled sheets. Annealed or tempered at 740−780°C (transverse samples) | <3,9 | 530 | 17 | ||
| Seamless hot-deformed pipes | 3,5−32 | 441 | 17 |
Mechanical properties at elevated temperatures
| t test,°C | σB, MPa | δ5, % | ψ, % | KCU, J/m2 | ||||||||||
| Annealing at 760−780°C. | ||||||||||||||
| 20 | 530 | 30 | 10 | |||||||||||
| 100 | 490 | 27 | 20 | |||||||||||
| 200 | 490 | 29 | 206 | |||||||||||
| 300 | 460 | 22 | 196 | |||||||||||
| 400 | 500 | 18 | 181 | |||||||||||
| 500 | 390 | 20 | 147 | |||||||||||
| 600 | 170 | 60 | 181 | |||||||||||
| 700 | 76 | 48 | 92 | 174 | ||||||||||
| 800 | 26 | 104 | 99 | 208 | ||||||||||
| 900 | 19 | 153 | 99 | 160 | ||||||||||
| 1000 | 11 | 147 | 100 | 151 | ||||||||||
| 1100 | 8 | 139 | 99 | 127 | ||||||||||
Technological properties of steel 15X28
| Forging temperature |
| Starts 950−1000, ends 750−800. Cooling is done in the air. |
| Weldability |
| limited. Manual arc welding with electrodes of EA-2 type and argon-arc welding are used for welding. Welding should be preferably carried out with heating to 150−300 C. |
| Tendency to tempering |
| is prone to tempering when heated in the range of 520 C because of the release of b-phase. |
Corrosion properties of steel 15X28
| Medium | Test temperature, °C | Test duration, h | Depth, mm/year |
| 60% H3PO4 solution | 20 | 100 | 0.04 |
| 80% H3PO4 solution | 20 | 100 | 0.1 |
| 68% H3PO4 solution | 80 | 20 | 0.65 |
Heat resistance of steel 15X28
| Medium | Temperature, °C | Test duration, h | Depth, mm/year | Resistance group or grade |
| Calm air | 1050 | 1520 | 0,45 | 6 |
| Airflow | 1050 | 100 | 0,7 | Reduced |
| 1.5% SO2 + air | 1050 | 100 | 2,9 | Low-resistant |
Physical properties of steel 15X28
| Test temperature, °С | 20 | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900 |
| Modulus of normal elasticity, E, GPa | 220 | 216 | 210 | 204 | 193 | 184 | 165 | |||
| Torsional shear modulus of elasticity G, GPa | 89 | 86 | 84 | 80 | 76 | 70 | 62 | |||
| Steel density, pn, kg/m3 | 7630 | |||||||||
| Thermal conductivity coefficient W/(m - °C) | 21 | 22 | 23 | 23 | 24 | 25 | ||||
| Electrical resistivity (p, nominal value - m) | 700 | |||||||||
| Test temperature,°C | 20−100 | 20−200 | 20−300 | 20−400 | 20−500 | 20−600 | 20−700 | 20−800 | 20−900 | 20−1000 |
| Coefficient of linear expansion (a, 10−6 1/°C) | 10.0 | 10.5 | 10.5 | 11.0 | 11.0 |
