Steel 25
Description
Steel 25
Steel 25: brand of steels and alloys. Below is a systematized information on the purpose, chemical composition, types of supplies, substitutes, temperature of critical points, physical, mechanical, technological and casting properties for the Steel 25 grade.
General steel 25
| Substitute brand |
| steel: 20, steel 30 |
| Delivery type |
| Circle 25, rolled sections, including shaped: GOST 1050−74, GOST 2590−71, GOST 2591−71, GOST 2879−69, GOST 8509−86, GOST 8510−86, GOST 8240−72, GOST 8239−72… Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78, GOST 10702−78. Polished bar and silver bar GOST 14955−77, GOST 10702−78. Thick sheet GOST 1577−81, GOST 19903−74. Thin sheet GOST 16523−70. Tape GOST 6009−74, GOST 2284−79. Strip GOST 1577−81, GOST 103−76, GOST 82−70. Wire GOST 5663−79, GOST 17305−71. Forgings and forged billets GOST 8479−70, GOST 1133−71. |
| Application |
| Axles, shafts, couplings, pawls, levers, forks, washers, rollers, bolts, flanges, tees, fasteners and other irrelevant parts; after HTT — screws, bushings, pawls and other parts, which are subject to requirements of high surface hardness and wear resistance with low core strength. |
Chemical composition of steel 25
| Chemical element |
% |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.50−0.80 |
| Copper (Cu), no more |
0.25 |
| Arsenic (As), no more |
0.08 |
| Nickel (Ni), no more |
0.25 |
| Sulfur (S), no more |
0.04 |
| Carbon (C) |
0.22−0.30 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr), no more |
0.25 |
Mechanical properties of steel 25
Mechanical properties at elevated temperatures
| test t, ° C |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
δ 10 ,% |
ψ,% |
KCU, J / m 2 |
| After rolling. Deformation rate 0.8 mm / min |
| 20 |
310 |
490 |
|
28 |
58 |
78 |
| 200 |
320 |
560 |
|
thirteen |
44 |
97 |
| 300 |
200 |
540 |
|
22 |
57 |
88 |
| 400 |
165 |
465 |
|
25 |
66 |
69 |
| 500 |
150 |
330 |
|
28 |
70 |
49 |
| Sample with a diameter of 6 mm and a length of 30 mm, rolled. Deformation rate 16 mm / min. Strain rate 0.009 1 / s. |
| 700 |
130 |
145 |
42 |
|
77 |
|
| 800 |
69 |
96 |
57 |
|
78 |
|
| 900 |
47 |
79 |
53 |
|
95 |
|
| 1000 |
40 |
54 |
60 |
|
100 |
|
| 1100 |
24 |
38 |
66 |
|
100 |
|
| 1200 |
fourteen |
23 |
101 |
|
100 |
|
| 1300 |
20 |
25 |
67 |
|
100 |
|
Mechanical properties of rolled products
| Heat treatment, delivery condition |
σ B, MPa |
δ 5 ,% |
δ 4 ,% |
ψ,% |
HB |
| Hot rolled steel, forged, calibrated and silver grade 2 after normalization |
450 |
23 |
|
50 |
|
| Calibrated steel grade 5 after annealing or high tempering |
410 |
19 |
|
50 |
|
| Calibrated work-hardened steel with special finishing without heat treatment |
540 |
7 |
|
40 |
217 |
| Normalized or hot rolled strips |
450 |
23 |
|
50 |
|
| Heat-treated sheet of the 1st-2nd category |
390−540 |
26 |
|
|
|
| Hot rolled sheet |
390−540 |
|
21 |
|
|
| Cold rolled sheet |
390−540 |
|
22 |
|
|
Mechanical properties of forgings
| Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
| Hardening. Vacation. Normalization. |
| <100 |
175 |
350 |
28 |
55 |
64 |
101−143 |
| 100−300 |
175 |
350 |
24 |
50 |
59 |
101−143 |
| 300−500 |
175 |
350 |
22 |
45 |
59 |
101−143 |
| <100 |
195 |
390 |
26 |
55 |
59 |
111−156 |
| 100−300 |
195 |
390 |
23 |
50 |
54 |
111−156 |
| 300−500 |
195 |
390 |
20 |
45 |
49 |
111−156 |
| <100 |
215 |
430 |
24 |
53 |
54 |
123−167 |
| 100−300 |
215 |
430 |
20 |
48 |
49 |
123−167 |
| <100 |
245 |
470 |
22 |
48 |
49 |
143−179 |
| Hardening. Vacation. |
| 100−300 |
275 |
530 |
17 |
38 |
34 |
156−197 |
Mechanical properties of steel after HTT
| Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
HB |
HRC e |
| Cementation 920−950 ° C, hardening 820−840 ° C, water, tempering 180−200 ° C, air. |
| 50 |
345 |
550 |
25 |
45 |
170 |
55−63 |
Technological properties of steel 25
| Forging temperature |
| Beginning 1280, end 700. Air cooling. |
| Weldability |
| It is welded without restrictions, except for parts after HTT. Methods of welding RDS, ADS submerged arc and gas shielded, KTS. |
| Machinability by cutting |
| In the hot-rolled state with σ B = 450−490 MPa K υ tv.spl. = 1.7 and K υ b.st. = 1.6. |
| Tendency to release ability |
| Not inclined. |
| Flock sensitivity |
| Not sensitive. |
Temperature of critical points of steel 25
| Critical point |
° C |
| Ac1 |
735 |
| Ac3 |
835 |
| Ar3 |
825 |
| Ar1 |
680 |
Impact strength of steel 25
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
+20 |
-20 |
-40 |
-60 |
| Annealing |
136−145 |
28−68 |
25−44 |
7.8 |
| Normalization |
196 |
97−149 |
43−115 |
37−49 |
Endurance limit steel 25
| σ -1, MPa |
n |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
| 203 |
|
460 |
330 |
Tempering 870 C, oil. Vacation 480 С. |
| 186 |
|
410 |
|
Annealing. |
| 245 |
1E + 7 |
|
|
Normalization |
| 225 |
|
400 |
|
After rolling. |
Physical properties of steel 25
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Normal elastic modulus, E, GPa |
198 |
196 |
191 |
186 |
163 |
|
|
|
|
|
| Torsional shear elastic modulus G, GPa |
81 |
80 |
76 |
73 |
70 |
66 |
61 |
|
|
|
| Density of steel, pn, kg / m 3 |
7820 |
|
|
|
|
|
|
|
|
|
| Thermal conductivity coefficient W / (m ° С) |
|
51 |
49 |
46 |
43 |
40 |
36 |
32 |
26 |
27 |
| Ud. electrical resistance (p, Nom. m) |
169 |
219 |
292 |
381 |
488 |
601 |
758 |
925 |
|
|
| Test temperature, ° С |
20−100 |
20−200 |
20−300 |
20−400 |
20−500 |
20−600 |
20−700 |
20−800 |
20−900 |
20−1000 |
| Linear expansion coefficient (a, 10−6 1 / ° С) |
12.2 |
13.0 |
13.7 |
14.3 |
14.7 |
15.0 |
15.2 |
12.7 |
12.4 |
13.4 |
| Specific heat (C, J / (kg ° C)) |
470 |
483 |
|
521 |
571 |
|
|
|
|
|