Steel 25Kh1MF
25Cr1MoV Steel
Steel 25Kh1MF: 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 brand — Steel 25Kh1MF.
General information on steel 25Kh1MF
| Type of delivery |
| Round 25h1mf, bars, including shaped: GOST 20072−74, GOST 2590−71, GOST 2591−71. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78. Strip GOST 103−76, GOST 4405−75, GOST 20072−74. Forged and forged blanks GOST 1133−71, GOST 20072−74. |
| Application . |
| Various parts operating at temperatures up to 540 ° C. Fasteners operating at temperatures from -40 ° C to +500 ° C. |
Chemical composition of steel 25Kh1MF
| Chemical element | % |
| Vanadium (V) | 0.15−0.30 |
| Silicon (Si) | 0.17−0.37 |
| Manganese (Mn) | 0.40−0.70 |
| Copper (Cu), not more than | 0.020 |
| Molybdenum (Mo) | 0.25−0.35 |
| Nickel (Ni), not more than | 0.30 |
| Sulfur (S), not more than | 0.025 |
| Carbon (C) | 0.22−0.29 |
| Phosphorus (P), not more than | 0.030 |
| Chromium (Cr) | 1.50−1.80 |
Mechanical properties of steel 25Kh1MF
| Section, mm | σ0, 2, MPa | σB, MPa | δ5, % | ψ, % | KCU, J/m2 | HB | ||||||||
| Rods: 880−900°C hardening, oil. Tempering 640−660°C, air. | ||||||||||||||
| 90 | 735 | 880 | 14 | 50 | 59 | |||||||||
| Bar stock: Quenching 930−950°C, oil. Tempering 620−660°C, air. | ||||||||||||||
| 90 | 665 | 780 | 16 | 50 | 59 | |||||||||
| Bar: Normalization 1000 °C, tempering 650 °C. | ||||||||||||||
| 810−870 | 940−980 | 17 | 51−58 | |||||||||||
| Forgings: quenching 860 °C, oil. Tempering 515 °C, air. | ||||||||||||||
| 250 | 780 | 930 | 10 | 40 | 49 | 285−321 | ||||||||
| 350 | 690 | 860 | 12 | 45 | 59 | 269−302 | ||||||||
| 450 | 590 | 780 | 14 | 45 | 59 | 241−277 | ||||||||
| Forgings: quenching 930−950°C, oil. Tempering 620−660°C, air. | ||||||||||||||
| 20−180 | 670 | 780 | 16 | 50 | 59 | |||||||||
Mechanical properties at elevated temperatures
| t test,°C | σ0, 2, MPa | σB, MPa | δ5, % | ψ, % | ||||||||||
| annealing at 920°C | ||||||||||||||
| 20 | 400 | 540 | 24 | 75 | ||||||||||
| 500 | 260 | 380 | 23 | 79 | ||||||||||
| 550 | 240 | 330 | 24 | 82 | ||||||||||
| Quenching 930−950°C, oil. Tempering 620−660°C | ||||||||||||||
| 20 | 790−1000 | 880−1050 | 16−19 | 60−64 | ||||||||||
| 400 | 610 | 710 | 17 | 68 | ||||||||||
| 450 | 590 | 690 | 17 | 71 | ||||||||||
| 500 | 580 | 620 | 19 | 75 | ||||||||||
| 550 | 490 | 550 | 20 | 78 | ||||||||||
Mechanical properties depending on tempering temperature
| t tempering temperature, °C | σ0, 2, MPa | σB, MPa | δ5, % | ψ, % | KCU, J/m2 | |||||||||
| 910−920°C hardening, oil | ||||||||||||||
| 540 | 1220 | 1270 | 13 | 58 | ||||||||||
| 570 | 1190 | 1230 | 16 | 61 | ||||||||||
| 600 | 1150 | 1190 | 18 | 61 | 78 | |||||||||
| 630 | 1060 | 1120 | 19 | 62 | 78 | |||||||||
| 660 | 880 | 960 | 19 | 69 | 127 | |||||||||
Mechanical properties at 20 C, depending on heat treatment
| Heat treatment, delivery condition | σ0, 2, MPa | σB, MPa | δ5, % | ψ, % | KCU, J/m2 | |||||||||
| Hardening at 950 °C, oil. Tempering 620°C | ||||||||||||||
| Heat soaking at 450 °C, 3000 h. | 940 | 1110 | 18 | 61 | 54 | |||||||||
| Heat soak 450 °C, 6000 h. | 990 | 1160 | 17 | 55 | 44 | |||||||||
| Heat soak 500 °C, 3000 h. | 980 | 1090 | 18 | 60 | 44−59 | |||||||||
| Heat soak 500 °C, 6000 h. | 950 | 1070 | 17 | 60 | 49−54 | |||||||||
| Normalization 1000 °C, air. Tempering 650 °C, | ||||||||||||||
| Heat soak 450 °C, 3000 h. | 800 | 970 | 15 | 52 | 41−49 | |||||||||
| Heat soak 500 °C, 3000 h. | 870 | 980 | 15 | 60 | 41 | |||||||||
Technological properties of 25Kh1MF steel
| Forging temperature |
| The beginning 1180, the end 850. Sections up to 60 mm are cooled in stacks in the air, 61−200 mm are subjected to low-temperature annealing. |
| Weldability |
| Difficult-to-weld. Welding methods: TIG and ADS. |
| Machinability |
| In normalized and tempered state with NV? 300 Kυ dv.spl. = 0.70, K υ b.st. = 0.25. |
| Tendency to tempering ability |
| is not prone to |
| Flocculation sensitivity |
| sensitive |
Temperature of critical points of 25Kh1MF steel
| Critical point | °С |
| Ac1 | 760 |
| Ac3 | 840 |
| Ar3 | 770 |
| Ar1 | 685 |
| Mn | 345 |
Hardenability of steel 25Kh1MF
| Distance from end face, mm / HRCe | |||||||||||
| 5 | 10 | 15 | 20 | 25 | 30 | 40 | 50 | 60 | |||
| 45−50,5 | 42,5−49,5 | 38,5−48 | 35,5−46,5 | 34−44,5 | 32,5−41,5 | 31−39,5 | 30−39,5 | 29,5−39,5 | |||
Physical properties of steel 25Kh1MF
| Test temperature,°C | 20 | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900 |
| Modulus of normal elasticity, E, GPa | 213 | 207 | 204 | 194 | 187 | 176 | 164 | |||
| Torsional shear modulus of elasticity G, GPa | 82 | 80 | 77 | 75 | 71 | 66 | 63 | |||
| Steel density, pn, kg/m3 | 7840 | 7790 | 7720 | 7650 | ||||||
| Thermal conductivity coefficient W/(m — °C) | 40 | 39 | 38 | 37 | 36 | 35 | ||||
| Electrical resistivity (p, Nm — m) | 312 | 396 | 475 | 574 | 680 | 826 | ||||
| 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) | 11.3 | 11.7 | 12.8 | 13.9 | 14.2 | 14.4 | ||||
| Specific heat capacity (C, J/(kg -°C)) | 462 |
