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Steel 20X3MVF

25X1MF 35CRM 20CR3MOVF 25X2M1F 38CR2MUA 30CRM 30CMA

20Cr3MoVF Steel

Steel 20Cr3MVF: a classifier of steels and alloys. Below is systematized information on the purpose, chemical composition, types of supply, substitutes, critical point temperatures, physical, mechanical, technological and foundry properties for the grade — Steel 20Cr3MVF.

General information on steel 20X3MVF

Kind of delivery
Sections, including shaped: GOST 20072−74, GOST 2590−71, GOST 2591−71. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78. Strips GOST 103−76, GOST 4405−75. Forged and forged blanks GOST 1133−71.
Application .
Fasteners and other parts operating at temperatures up to 540−560 ° C.

Chemical composition of steel 20X3MVF

Chemical element %
Vanadium (V) 0.60−0.85
Tungsten (W) 0.30−0.50
Silicon (Si) 0.17−0.37
Manganese (Mn) 0.25−0.50
Copper (Cu), not more than 0.20
Molybdenum (Mo) 0.35−0.55
Nickel (Ni), not more than 0.30
Sulfur (S), max. 0.025
Carbon (C) 0.15−0.23
Phosphorus (P), not more than 0.030
Chromium (Cr) 2.80−3.30

Mechanical properties of steel 20X3MVF

Mechanical properties at elevated temperatures

t test,°C σ0.2, MPa σB, MPa δ5, % ψ, % KCU, J/m2
Disks 600−1000 mm in diameter, 100−150 mm thick. Hardened at 1050 °C, oil. Tempering at 700 °C. (Tengential samples).
20 730−810 870−910 13 45−50 34−44
200 700 780 12 55 67
300 700 780 10 39 88
400 660 720 10 33 83
500 580−610 600−630   44−52 78
550 510−550 530−560 10−12 44 59−78
580 480−500 490−540 11 27−40 59−78
Rotor forging 47 t, barrel diameter 965−1075 mm. Normalization 1050 °C, Hardening 1000 °C, oil. Tempering 670 °C, cooling with furnace to 150 °C. (Tangential samples)
20 590−690 690−780 12−18 41−68 39−108
300 510−600 600−680 11−15 54−61 108−122
400 500−590 550−560 13−16 57−65 98−118
500 450−570 470−570 15−20 69−72 88−118
550 400−510 410−520 12−21 65−80 88−118
600 340−450 360−460 18−23 70−84 88−108
Specimen 6 mm in diameter, 30 mm long, forged and normalized. Deformation rate of 16 mm/minute. Strain rate 0.009 1/s.
1000 49 72 56 100  
1050 31 49 58 100  
1100 22 45 66 100  
1150 15 26 77 100  
1200 17 27 79 100  

Mechanical properties of the bar

Heat treatment, delivery condition Section, mm σ0, 2, MPa σB, MPa δ5, % ψ, % KCU, J/m2
Hardening at 1030−1060°C in oil. Tempering 660−700°C, air. 90 735 880 12 40 59

Mechanical properties in the long term strength test

Creep strength, MPa Creep rate, %/h t test,°C Ultimate long-term strength, MPa Test duration, h t test, h
177 1/10000 500 333 10000 500
147 1/100000 500 294 100000 500
127 1/10000 550 196 10000 550
98 1/100000 550 157 100000 550
49 1/100000 580 137 10000 580
      98 100000 580

Technological properties of steel 20Х3МВФ

Forging temperature
The beginning 1240, the end 780. Sections up to 50 mm are cooled in boxes, 51−700 mm are subjected to single supercooled annealing.
Weldability
Limited weldability. Welding methods: РДС — heating and subsequent heat treatment is necessary, КТС.
machinability by cutting
In the annealed condition at HB 157 and σB = 530 MPa Kυ of the fused material. = 1.5, K υ b.st. = 1.1.

Temperature of critical points of 20X3MVF steel

Critical point °С
Ac1 815
Ac3 925
Ar3 795
Ar1 690

Endurance limit of 20Kh3MVF steel

σ-1, MPa n σB, MPa σ0, 2, MPa Heat treatment, state of steel
314−333 1Е+7 760 640 Rotor forging, barrel diameter 860 mm. Annealing 950 C. Normalization 1100 C. Quenching 980−1020 С, oil. Tempering 660−680 C.

Physical properties of steel 20Х3МВФ

Temperature, °С 20 100 200 300 400 500 600 700 800 900
Modulus of normal elasticity, E, GPa 207 204 200 193 186 182 117 171 164  
Steel density, pn, kg/m3 7800       7690 7660 7620      
Thermal conductivity coefficient W/(m — °C)   36 33 32 31 30 29 29    
Electrical resistivity (p, nominal value — m)   398 465 544 640 743 859 982    
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) 10.6 11.5 11.8 12.1 12.6 13.0        
Specific heat capacity (C, J/(kg -°C)) 502 560 610 650 710 750        

Sensitivity to embrittlement of 20X3MVF steel

Temperature, °C Time, h KCU, J/cm2
- Initial state 44
500 10000 73
550 10000 49
600 5000 73