Designation
Name |
The value |
Designation GOST Cyrillic |
20Х3МВФ |
Designation GOST Latin |
20X3MBF |
Transliteration |
20H3MVF |
By chemical elements |
20Cr3MoWV |
Name |
The value |
Designation GOST Cyrillic |
ЭИ415 |
Designation GOST Latin |
EI415 |
Transliteration |
EhI415 |
By chemical elements |
- |
Description
20KH3MVF steel is used: for the manufacture of rotors, discs, forgings, bolts, high pressure pipe for chemical apparatus, and hydrogenation plants, special fasteners and other parts operating at temperatures up to +540−560 °C; piping details with quenching in oil and tempering to the air; tubes for plants of chemical and petrochemical plants with nominal pressure PN=19.6−98 MPa (200−1000 kgf/cm2) nitrided parts of the aviation industry; billets of shafts and one-piece rotors stationary and transport steam turbines.
Note
The case hardening steel of pearlitic class.
Temperature intense scaling +600 °C.
Standards
Name |
Code |
Standards |
Sheets and strips |
В23 |
GOST 103-2006 |
Bars and shapes |
В22 |
GOST 1133-71, GOST 2590-2006, GOST 2591-2006 |
Sheets and strips |
В33 |
GOST 4405-75, TU 14-1-702-73 |
Bars and shapes |
В32 |
GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, GOST 20072-74, TU 14-1-2090-77, TU 14-1-3957-85, TU 14-11-245-88 |
Classification, nomenclature and General rules |
В20 |
OST 1 90005-91 |
Blanks. Of the workpiece. Slabs |
В31 |
OST 1 90157-74 |
Blanks. Of the workpiece. Slabs |
В21 |
OST 1 90176-75 |
Processing of metals by pressure. Forgings |
В03 |
OST 26-01-135-81, TU 108-1029-81 |
Thermal and thermochemical treatment of metals |
В04 |
ST ЦКБА 026-2005 |
Steel pipes and fittings to them |
В62 |
TU 14-3Р-251-2007, TU 14-3-251-74 |
Chemical composition
Standard |
C |
S |
P |
Mn |
Cr |
Si |
Ni |
Fe |
Cu |
V |
Ti |
Mo |
W |
TU 108-1029-81 |
0.17-0.24 |
≤0.022 |
≤0.025 |
0.25-0.6 |
2.4-3.3 |
≤0.4 |
≤0.5 |
Rest |
≤0.25 |
0.6-0.85 |
- |
0.35-0.55 |
0.3-0.5 |
TU 14-3Р-251-2007 |
0.15-0.23 |
≤0.025 |
≤0.03 |
0.25-0.5 |
2.8-3.3 |
0.17-0.37 |
≤0.3 |
Rest |
≤0.2 |
0.6-0.85 |
- |
0.35-0.55 |
0.3-0.5 |
TU 14-1-2090-77 |
0.15-0.2 |
≤0.025 |
≤0.03 |
0.25-0.5 |
2.8-3.3 |
0.17-0.37 |
≤0.5 |
Rest |
≤0.3 |
0.6-0.85 |
- |
0.35-0.55 |
0.3-0.5 |
GOST 20072-74 |
0.15-0.23 |
≤0.025 |
≤0.03 |
0.25-0.5 |
2.8-3.3 |
0.17-0.37 |
≤0.3 |
Rest |
≤0.2 |
0.6-0.85 |
≤0.03 |
0.35-0.55 |
0.3-0.5 |
Fe is the basis.
According to GOST 20072-74, when steel is scrap-process, the content of Cu ≤ 0.30%. The presence of titanium is up to 0.030%. When smelting steel by the method of electroslag remelting, the mass fraction of sulfur should not be more than 0.015%.
According to TU 108-1029-81, the chemical composition is given for steel grade 20Х3МВФА (ЭИ415А). In the workpieces, deviations in the content of the elements indicated in the table are allowed: carbon ± 0.010%, silicon + 0.030%. For metal VDP, the deviation of manganese content +0.10% / - 0.15% is allowed. The deviation of the silicon content in the metal VDP and ESR is allowed within ± 0.050%. In the ESR steel, the sulfur content should not be more than 0.015%.
According to TU 14-1-2090-77, the chemical composition is given for steel grade 20X3MVF (EI415). In steel grade 20Х3МВФ-Ш (ЭИ415-Ш) the sulfur content should not be more than 0,015%. If all the requirements of the specification are met, deviations in chemical composition are allowed in accordance with table 2 of GOST 20072. The content of residual elements is allowed: nickel - no more than 0.50% and copper - no more than 0.30%.
Mechanical properties
Section, mm |
sT|s0,2, MPa |
σU, MPa |
d5, % |
y, % |
KCU, kJ/m2 |
HB, MPa |
HRC |
Discs with a diameter of 600-1000 mm with a thickness of 100-150 mm. Quenching in oil from 1050 °C to + Vacation at 700 °C (sample Tangenziale) |
- |
730-810 |
870-910 |
13 |
45-50 |
- |
- |
- |
Gradation of performance properties of the finished heat-treated parts for OST 1 90005-91 |
- |
- |
- |
- |
- |
- |
321-415 |
31-43.5 |
Discs with a diameter of 600-1000 mm with a thickness of 100-150 mm. Quenching in oil from 1050 °C to + Vacation at 700 °C (sample Tangenziale) |
- |
700 |
780 |
12 |
55 |
- |
- |
- |
Gradation of performance properties of the finished heat-treated parts for OST 1 90005-91 |
- |
- |
- |
- |
- |
- |
302-363 |
28-39 |
Billet shafts and rotors of steam turbines on the other 108-1029-81 (in the delivery condition specified strength and direction and place the cuttings sample) |
- |
589-736 |
≥736 |
≥13 |
≥40 |
≥490 |
- |
- |
Discs with a diameter of 600-1000 mm with a thickness of 100-150 mm. Quenching in oil from 1050 °C to + Vacation at 700 °C (sample Tangenziale) |
- |
700 |
780 |
10 |
39 |
- |
- |
- |
Billet shafts and rotors of steam turbines on the other 108-1029-81 (in the delivery condition specified strength and direction and place the cuttings sample) |
- |
589-736 |
≥716 |
≥11 |
≥32 |
≥390 |
- |
- |
Discs with a diameter of 600-1000 mm with a thickness of 100-150 mm. Quenching in oil from 1050 °C to + Vacation at 700 °C (sample Tangenziale) |
- |
660 |
720 |
10 |
33 |
- |
- |
- |
Blank pieces of pipe fittings. Quenching in oil from 1030-1080 °C (exposure for 2.5-4.5 hours depending on the thickness and weight of the workpiece) + Vacation at 660-700 °C, air cooling |
≤25 |
735-835 |
≥880 |
≥12 |
≥40 |
≥588 |
277-321 |
- |
Discs with a diameter of 600-1000 mm with a thickness of 100-150 mm. Quenching in oil from 1050 °C to + Vacation at 700 °C (sample Tangenziale) |
- |
580-610 |
600-630 |
- |
44-52 |
- |
- |
- |
Blank pieces of pipe fittings. Quenching in oil from 1030-1080 °C (exposure for 2.5-4.5 hours depending on the thickness and weight of the workpiece) + Vacation at 660-700 °C, air cooling |
≤400 |
640-735 |
≥735 |
≥13 |
≥40 |
≥490 |
248-293 |
- |
Discs with a diameter of 600-1000 mm with a thickness of 100-150 mm. Quenching in oil from 1050 °C to + Vacation at 700 °C (sample Tangenziale) |
- |
510-550 |
530-560 |
10-12 |
44 |
- |
- |
- |
Quenching in oil with 1030-1060 °C + Vacation at 660-700 °C |
- |
620-650 |
730-750 |
11-13 |
32-40 |
392-491 |
- |
- |
Discs with a diameter of 600-1000 mm with a thickness of 100-150 mm. Quenching in oil from 1050 °C to + Vacation at 700 °C (sample Tangenziale) |
- |
480-500 |
490-540 |
11 |
27-40 |
- |
- |
- |
Quenching in oil with 1030-1060 °C + Vacation at 660-700 °C |
≤25 |
≥750 |
≥900 |
≥12 |
≥40 |
≥589 |
- |
- |
A sample with a diameter of 6 mm, length 30 mm, forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s |
- |
≥49 |
≥72 |
≥56 |
≥100 |
- |
- |
- |
Bars hot rolled and forged on the other 14-1-2090-77. The longitudinal samples. Quenching in oil with 1030-1060 °C + Vacation at 660-700 °C (delay of 1-3 h), air cooling |
|
≥735 |
≥880 |
≥12 |
≥40 |
≥588 |
269-341 |
- |
A sample with a diameter of 6 mm, length 30 mm, forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s |
- |
≥31 |
≥49 |
≥58 |
≥100 |
- |
- |
- |
Bars hot rolled and forged on the other 14-1-2090-77. The longitudinal samples. Quenching in oil with 900-1950 °C + Vacation at 250-350 °C (exposure 2 hours), air cooling |
|
≥885 |
≥1080 |
≥10 |
≥55 |
≥686 |
320-415 |
- |
A sample with a diameter of 6 mm, length 30 mm, forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s |
- |
≥22 |
≥45 |
≥66 |
≥100 |
- |
- |
- |
Rolled steel. Quenching in oil with 1030-1060 °C + Vacation at 660-700 °C, air cooling |
≤90 |
≥735 |
≥880 |
≥12 |
≥40 |
≥579 |
- |
- |
A sample with a diameter of 6 mm, length 30 mm, forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s |
- |
≥15 |
≥26 |
≥77 |
≥100 |
- |
- |
- |
Seamless pipes for chemical and petrochemical industries in the state of delivery (indicate the cutting direction of sample) |
|
≥490 |
≥784 |
≥12 |
- |
≥490 |
241-285 |
- |
A sample with a diameter of 6 mm, length 30 mm, forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s |
- |
≥17 |
≥27 |
≥79 |
≥100 |
- |
- |
- |
Seamless pipes for chemical and petrochemical industries in the state of delivery (indicate the cutting direction of sample) |
|
≥490 |
≥784 |
≥14 |
- |
≥590 |
241-285 |
- |
The forging of the rotor 47 so that the barrel diameter is mm. 965-1075 Normalization at 1050 °C + Quenched in oil from 1000 °C + Vacation at 670 °C, cooling with the furnace to 150 °C then in air (samples tangential) |
- |
590-690 |
690-780 |
12-18 |
41-68 |
- |
- |
- |
Forming at OST 1 90176-75. Quenching in oil with 1030-1060 °C + Vacation at 660-700 °C (aging for 1 h), air cooling |
|
≥735 |
≥883 |
≥12 |
≥40 |
≥588 |
285-331 |
- |
The forging of the rotor 47 so that the barrel diameter is mm. 965-1075 Normalization at 1050 °C + Quenched in oil from 1000 °C + Vacation at 670 °C, cooling with the furnace to 150 °C then in air (samples tangential) |
- |
510-600 |
600-680 |
11-15 |
54-61 |
- |
- |
- |
- |
500-590 |
550-560 |
13-16 |
57-65 |
- |
- |
- |
- |
450-570 |
470-570 |
15-20 |
69-72 |
- |
- |
- |
- |
400-510 |
410-520 |
12-21 |
65-80 |
- |
- |
- |
- |
340-450 |
360-460 |
18-23 |
70-84 |
- |
- |
- |
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 |
HB |
Brinell hardness number |
HRC |
Rockwell hardness (indenter diamond spheroconical) |
Physical characteristics
Temperature |
Е, HPa |
r, kg/m3 |
l, W/(m · °C) |
R, Mr. · m |
a, 10-6 1/°C |
С, J/(kg · °C) |
0 |
207 |
7800 |
- |
- |
- |
- |
20 |
207 |
7800 |
385 |
- |
- |
- |
100 |
204 |
- |
36 |
398 |
106 |
502 |
200 |
200 |
- |
33 |
465 |
115 |
560 |
300 |
193 |
- |
32 |
544 |
118 |
610 |
400 |
186 |
7690 |
31 |
640 |
121 |
650 |
500 |
182 |
7660 |
30 |
743 |
126 |
710 |
600 |
117 |
7620 |
29 |
859 |
126 |
710 |
700 |
171 |
- |
29 |
982 |
- |
- |
800 |
164 |
- |
- |
- |
13 |
750 |
A description of the physical symbols
Name |
Description |
Е |
The normal elasticity modulus |
r |
Density |
l |
Coefficient of thermal conductivity |
R |
UD. the resistivity |
Technological properties
Name |
The value |
Weldability |
limited weldability. Welding methods: RDS - necessary heating and subsequent heat treatment, the CCC. |
The temperature of forging |
Start - 1240 °C, the end - 780 °C. the cross Sections up to 50 mm are cooled in boxes, 51-700 mm is subjected to annealing, one hypothermia. |
Machinability |
In the annealed condition with blower SB 157 HB=530 MPa Kn TV.SPL.=1.5 Kn b.St.=1.1 |