Steel 25ХСНВФА (ВП25)

Designation

Name The value
Designation GOST Cyrillic 25ХСНВФА
Designation GOST Latin 25XCHBFA
Transliteration 25HSNVFA
By chemical elements 25CrСНWV
Name The value
Designation GOST Cyrillic ВП25
Designation GOST Latin BP25
Transliteration VP25
By chemical elements WP25

Description

25ХСНВФА steel is used: for the manufacture of semi-finished strips, rods and rolled plates, used for production of capacitive equipment of power plant engineering; solid-rolled rings for different purposes.

Standards

Name Code Standards
Bars and shapes В32 OST 1 92049-76, TU 14-1-1447-75
Sheets and strips В33 TU 14-1-1369-75, TU 14-1-4461-88
Blanks. Of the workpiece. Slabs В31 TU 14-1-4878-90

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu V W
TU 14-1-1447-75 0.23-0.28 ≤0.01 ≤0.015 0.5-0.8 0.9-1.2 0.9-1.2 0.9-1.2 Rest ≤0.15 0.05-0.15 0.5-1
Fe is the basis.
According to TU 14-1-4461-88, the chemical composition of the steel should comply with the standards specified in Table 2 (Appendix 1), sent on request by the Central Research Institute of Chemical Technology named after Bardin. The sulfur content of sulfur is not more than 0.011%, phosphorus is not more than 0.015%, while the total content of sulfur and phosphorus should not be more than 0.022%. The residual copper content should not be more than 0.15%. With the consent of the consumer, it is allowed - up to 0.20%. The residual molybdenum content is allowed up to 0.10%. In the finished sheets the following deviations in chemical composition from the norms indicated in Table 2 are allowed: carbon + 0.02 / -0.010%; tungsten ± 0.10%; manganese, silicon, chromium and nickel ± 0.050%; molybdenum ± 0.030%; vanadium +0.020%. Partial or complete replacement of tungsten by molybdenum from the calculation of 2.5 mass fraction of tungsten is allowed with one mass fraction of molybdenum.
According to TU 14-1-1369-75, the chemical composition of the steel should correspond to the norms indicated in Table 2 (Appendix 4), sent on request. The sulfur content of sulfur is not more than 0.010%, phosphorus is not more than 0.015%, while the total content of sulfur and phosphorus should not be more than 0.022%. The residual copper content should not be more than 0.15%. With the consent of the consumer, it is allowed - up to 0.20%. The residual molybdenum content is allowed up to 0.10%. When observing mechanical properties, deviations from the chemical composition are allowed within the limits: carbon + 0.02 / -0.010% (in finished sheets); tungsten ± 0.10%; manganese, silicon, chromium and nickel ± 0.050%; molybdenum ± 0.030%; vanadium +0.020%. Partial or complete replacement of tungsten by molybdenum from the calculation of 2.5 mass fraction of tungsten is allowed with one mass fraction of molybdenum. When the tungsten is completely replaced, the molybdenum content should be in the range 0.25-0.40%; while the residual content of tungsten is allowed up to 0.20%.
According to TU 14-1-1447-75 the sum of sulfur and phosphorus should not exceed 0.022%. It is allowed to increase the content of sulfur or phosphorus by 0.0010% with a total content of no more than 0.022%. Deviations in the established norms for the chemical composition are allowed: carbon ± 0.010%, chromium, nickel, silicon, manganese, tungsten ± 0.050%, molybdenum ± 0.030%, vanadium + 0.020%. Full or partial replacement of tungsten with molybdenum is allowed at the rate of 2.5 parts by weight of tungsten is replaced by one part by weight of molybdenum. When molybdenum is completely replaced by tungsten, the molybdenum content should be 0.30-0.40%. In the case of partial replacement of tungsten with molybdenum, the actual content of tungsten is recalculated to molybdenum in a ratio of 2.5: 1 and the conditional total molybdenum and tungsten content in terms of molybdenum should correspond to the specified molybdenum content when the tungsten is completely replaced. In steel without the replacement of tungsten by molybdenum, the residual molybdenum content of 0.10% is allowed. With the complete replacement of tungsten by molybdenum, the residual content of tungsten is allowed up to 0.15%.
According to TU 14-1-4878-90, the chemical composition of the steel must comply with the standards specified in Appendix 1, sent on request by the Central Research Institute of Chemical Technology named after Bardin. Deviations from the chemical composition are allowed: carbon ± 0.010%, chromium, nickel, silicon, manganese and tungsten ± 0.050% each, molybdenum ± 0.030%, vanadium +0.020%.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2 HB, MPa
Ring forged in OST 1 92049-76. Quenching in oil with 900-940 °C + Vacation at 300-380 °C (extract 2-3 h), cooling in air or under a fan
≥1120 ≥1350 ≥6.7 ≥32 ≥343 -
The leaves of g/K and x/K on the other 14-1-1369-75. Quenching in oil with 900-940 °C + Vacation at 300-380 °C, air cooling (in cross-section the thickness of the sheets)
0.8-1.5 ≥1176 ≥1372 ≥7 - - -
1.6-2.5 ≥1176 ≥1372 ≥8 - - -
2.6-5.6 ≥1225 ≥1421 ≥7.5 - - -
2.6-5.6 ≥1225 ≥1421 ≥8 - - -
The leaves of g/K and x/K on the other 14-1-4461-88. Quenching in oil with 910-940 °C + Vacation at 300-380 °C, air cooling (heating for hardening must eliminate the carburization and decarburization, the samples transverse)
- ≥1420 ≥7.5 - - -
Bars and stripes on the other 14-1-1447-75. Quenching in oil with 900-940 °C + Vacation at 300-380 °C (delay 2-3 hours), air cooling
≥1175 ≥1420 ≥9 ≥40 ≥440 -
The bars heat treated in the delivery condition on the other 14-1-1447-75 (longitudinal samples)
≥1175 ≥1420 ≥9 ≥40 ≥431 ≥241
Bullion on the other 14-1-4878-90. Samples from the control and the forged (rolled) billet square 60-80 mm in the longitudinal direction. quenching in oil with 900-940 °C + Vacation at 300-380 °C (delay 2-3 hours), air cooling
≥1175 ≥1420 ≥9 ≥40 ≥441 -

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

Technological properties

Name The value
Weldability For welding with direct current designs of heat-treatable high-strength steels and for surfacing layers of medium hardness (3 layer 320 LC) are applied to the electrodes SSSI - 13 and wire brand 18ХМА. The deposition rate of 10 g/A-h
Macrostructure and pollution The contamination of steel ingots on the other 14-1-4878-90 non-metallic inclusions, as measured according to GOST 1778 at the maximum point should not exceed 4.0 points for each type of inclusions (OS, OT, SH, SP, SN, S).
Microstructure The size of austenite grains in the steel should conform 5-8 number according to GOST 5639.