Steel 25

Designation

Name The value
Designation GOST Cyrillic 25
Designation GOST Latin 25
Transliteration 25
By chemical elements 25

Description

25 steel is used: for the manufacture of sheet metal, 1−2 mm 4−14 category, intended for cold forming; axes, shafts (including ship), couplings, dogs, levers, plugs, washers, rollers, bolts, flanges, tees, fasteners and other neotectonic components; screws, bushings, dogs and other details, which are requirements of high surface hardness and wear resistance at low strength core (after chemical-thermal treatment (HTO); details of pipeline valves (after hardening); solid-rolled rings for different purposes.

Note

The degree of deoxidation — SP.

Standards

Name Code Standards
Bars and shapes В32 GOST 1050-88, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 10702-78, GOST 14955-77, GOST 1050-2013, OST 1 92049-76, TU 14-1-5414-2001, TU 14-1-2118-77, TU 14-1-3651-83, TU 14-1-4597-89, TU 14-11-245-88, TU 14-1-1271-75, TU 14-1-5228-93, TU 14-136-367-2008
Bars and shapes В22 GOST 1133-71, GOST 8239-89, GOST 8240-97, GOST 8278-83, GOST 8281-80, GOST 8282-83, GOST 8283-93, GOST 8319.0-75, GOST 8509-93, GOST 8510-86, GOST 9234-74, GOST 11474-76, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006, OST 5.9087-84, TU 14-2-341-78
Sheets and strips В33 GOST 1577-93, GOST 4041-71, TU 14-1-1557-76, TU 14-1-4516-88
Tape В34 GOST 2284-79
Steel pipes and fittings to them В62 GOST 3262-75, GOST 20295-85, GOST 24950-81, TU 14-3-1428-86
Tape В24 GOST 3560-73
Steel wire medium and high carbon В72 GOST 3920-70, GOST 7372-79, GOST 9389-75, GOST 9850-72, GOST 17305-91, GOST 26366-84
Low carbon steel wire В71 GOST 5663-79
Sheets and strips В23 GOST 82-70, GOST 14918-80, GOST 16523-97, GOST 16523-89, GOST 16523-70, GOST 103-2006, GOST 19903-90, TU 14-1-1934-76, TU 14-1-4632-93
Processing of metals by pressure. Forgings В03 GOST 8479-70, OST 5Р.9125-84, ST ЦКБА 010-2004
Blanks. Of the workpiece. Slabs В31 OST 3-1686-90, TU 108.1461-87, TU 14-1-4944-90, TU 1-92-156-90
Thermal and thermochemical treatment of metals В04 ST ЦКБА 026-2005

Chemical composition

Standard C S P Mn Cr Si Ni Fe N As
GOST 1050-88 0.22-0.3 ≤0.04 ≤0.035 0.5-0.8 ≤0.25 0.17-0.37 ≤0.3 Rest ≤0.006 ≤0.08
GOST 10702-78 0.22-0.3 ≤0.04 ≤0.035 ≤0.6 ≤0.25 ≤0.2 ≤0.3 Rest ≤0.006 ≤0.08
Fe is the basis.
According to GOST 1050-88, the nitrogen content is specified for the steel of the oxygen-converter method of smelting. For all other types of smelting, the nitrogen content was N≤0.008%.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % d4 d10 y, % KCU, kJ/m2 HB, MPa HRC HRB
Rolled sheet 1-2 categories of heat-treated (annealing, normalization, high tempering or normalizing + tempering) in the delivery state according to GOST 4041-71
4-14 - 390-540 ≥26 - ≥23 - - ≤138 - ≤76
Wire for cold heading as supplied by GOST 5663-79
- - 470-620 - - - ≥55 - - - -
- - ≤640 - - - ≥50 - - - -
Hot-rolled steel and hot rolled with special surface finish
- - - - - - - - ≤170 - -
- - - - - - - - ≤156 - -
Steel calibrated and calibrated with special surface finish
- - ≥540 ≥7 - - ≥40 - ≤217 - -
- - ≤540 - - - ≥50 - ≤170 - -
- - ≤490 - - - ≥50 - ≤170 - -
Forgings. Normalization at 880-900 °C
≥275 ≥450 ≥23 - - ≥55 ≥882 121-171 - -
Cold-rolled steel strip of 0.1-4.0 mm in the delivery state according to GOST 2284-79
- - 540-880 - - - - - - - -
- - 340-590 - ≥18 - - - - - -
- - 340-540 - ≥18 - - - - - -
Steel, hot-rolled, forged, calibrated and silverfish 2nd category after normalization
- - ≥450 ≥23 - - ≥50 - - - -
Steel grooved 5-th category after annealing or high holidays
- - ≤410 ≥19 - - ≥50 - - - -
Ring forged in OST 1 92049-76. Normalization
25 ≥255 ≥430 ≥17 - - ≥40 ≥686 - - -
Forgings. Hardening + Vacation
100-300 ≥275 ≥530 ≥17 - - ≥38 ≥334 156-197 - -
Blank pieces of pipe fittings. Extract at 890-910 °C (2.5-4.0 hours depending on the thickness and weight of the workpiece) annealing in air
≤100 ≥245 ≥470 ≥22 - - ≥48 ≥481 143-179 - -
100-300 ≥215 ≥390 ≥20 - - ≥48 ≥481 123-167 - -
Hot-rolled strip. Normalization
- - ≥450 ≥23 - - ≥50 - - - -
Forgings. Hardening + vacation + normalization
100-300 ≥175 ≥350 ≥24 - - ≥50 ≥579 101-143 - -
300-500 ≥175 ≥350 ≥22 - - ≥45 ≥579 101-143 - -
100 ≥175 ≥350 ≥28 - - ≥55 ≥628 101-143 - -
100-300 ≥195 ≥390 ≥23 - - ≥50 ≥530 111-156 - -
300-500 ≥195 ≥390 ≥20 - - ≥45 ≥481 111-156 - -
100 ≥195 ≥390 ≥26 - - ≥55 ≥579 111-156 - -
100-300 ≥215 ≥430 ≥20 - - ≥48 ≥481 123-167 - -
100 ≥215 ≥430 ≥24 - - ≥53 ≥530 123-167 - -
100 ≥245 ≥470 ≥22 - - ≥48 ≥481 143-179 - -
Sheet 1 and 2 categories
- 390-540 ≥26 - - - - - - -
Hot-rolled sheet in the delivery condition. Group strength К390В
≤2 - 390-590 - ≥19 - - - - - -
2-3.9 - 390-590 - ≥20 - - - - - -
Cold-rolled sheet in the delivery condition. Group strength К390В
≤2 - 390-590 - ≥20 - - - - - -
2-3.9 - 390-590 - ≥21 - - - - - -
Cementation at 920-950 °C + quenching in water from 820-840 °C + vacation at 180-200 °C, air cooling
50 ≥345 ≥550 ≥25 - - ≥45 - ≥170 55-63 -
A sample with a diameter of 6 mm and a length of 30 mm, laminated. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s
- ≥130 ≥145 ≥42 - - ≥77 - - - -
- ≥69 ≥96 ≥57 - - ≥78 - - - -
- ≥47 ≥79 ≥53 - - ≥95 - - - -
- ≥40 ≥54 ≥60 - - ≥100 - - - -
- ≥24 ≥38 ≥66 - - ≥100 - - - -
- ≥14 ≥23 ≥101 - - ≥100 - - - -
- ≥20 ≥25 ≥67 - - ≥100 - - - -
After rolling. The rate of deformation of 0.8 mm/min.
- ≥310 ≥490 - - ≥28 ≥58 ≥765 - - -
- ≥320 ≥560 - - ≥13 ≥44 ≥952 - - -
- ≥200 ≥540 - - ≥22 ≥57 ≥863 - - -
- ≥165 ≥465 - - ≥25 ≥66 ≥677 - - -
- ≥150 ≥330 - - ≥28 ≥70 ≥481 - - -

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
d4 Elongation after rupture
d10 Elongation after rupture
y The relative narrowing
KCU Toughness
HB Brinell hardness number
HRC Rockwell hardness (indenter diamond spheroconical)
HRB Rockwell hardness (indenter steel, spherical)

Physical characteristics

Temperature Е, HPa G, HPa l, W/(m · °C) R, Mr. · m a, 10-6 1/°C С, J/(kg · °C)
300 186 73 46 381 137 483
400 163 70 43 488 143 521
500 - 66 40 601 147 521
600 - 61 36 758 15 -
700 - - 32 925 152 571

A description of the physical symbols

Name Description
Е The normal elasticity modulus
r Density
l Coefficient of thermal conductivity
R UD. the resistivity
a The coefficient of linear expansion

Technological properties

Name The value
Weldability Welded without restriction, except detali after HTO. The welding methods of SMAW, ADS submerged arc and gas protection, the CCC.
Склонность к отпускной хрупкости tend not
The temperature of forging Start - 1280 °C, end - 700 °C. air Cooling.
Flock-sensitive sensitivity not sensitive
Machinability In the hot rolled condition when blower SB=450-490 MPa Kn TV.SPL.=1.7 Kn b.St.=1.6
Surfacing Surfacing of sealing surfaces of valves in accordance with OST 26-07-2028-81 is made by manual arc welding electrodes type e-20X13 with plaster SSSI-13НЖ, NII-48, NII-48Ж-1 or SV wire-12H13 or SV-20X13. Surface preparation for overlay welding is performed by machining. Surfacing is performed with preliminary and accompanying heating to 400-450 °C is not less than 3 layers with thickness not less than 4 mm, excluding allowance for machining. Heat treatment after welding is produced by tempering at 550-600 °C (delay of 2-5 h) hardness HB=301-350, at 600-650 °C (delay of 2-5 h) hardness HB=240 to 300, at 400-450 °C (delay of 2-5 h) hardness HB=351-400. The temperature of the furnace when loading the details for the home should be no more than 300 °C.