Steel 45ХН
Description
Steel 45ХН
Steel 45ХН: 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 grade — Steel 45XN.
General information about steel 45ХН
| Substitute brand |
| steel 40ХН |
| Delivery type |
| Long products, including shaped: GOST 4543−71, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78, GOST 1051−73. Polished bar and silver bar GOST 14955−77. Strip GOST 103−76. Forgings and forged billets GOST 1133−71, GOST 8479−70. Pipes OST 14−21−77. |
| Application |
| Crankshafts, connecting rods, gears, spindles, couplings, bolts and other critical parts. |
Chemical composition of 45ХН steel
| Chemical element |
% |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.50−0.80 |
| Copper (Cu), no more |
0.30 |
| Nickel (Ni) |
1.00−1.40 |
| Sulfur (S), no more |
0.035 |
| Carbon (C) |
0.41−0.49 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr) |
0.45−0.75 |
Mechanical properties of 45ХН steel
Mechanical properties
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
| Bar. Hardening 820 ° C, water or oil. Vacation 530 ° C, water or oil. |
| |
25 |
835 |
1030 |
ten |
45 |
69 |
|
| Forgings. Hardening. Vacation |
| KP 590 |
<100 |
590 |
735 |
fourteen |
45 |
59 |
235−277 |
| KP 640 |
<100 |
640 |
785 |
thirteen |
42 |
59 |
248−293 |
Mechanical properties at elevated temperatures
| test t, ° C |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
| Hardening 840 ° С, oil. Vacation 480 ° C. |
| 20 |
720 |
910 |
21 |
| 150 |
680 |
880 |
19 |
| 290 |
670 |
|
27 |
| 425 |
520 |
670 |
25 |
| 535 |
210 |
440 |
33 |
Mechanical properties depending on the tempering temperature
| vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
HB |
| Hardening 815 ° С, oil. |
| 200 |
1530 |
1690 |
8 |
24 |
460 |
| 300 |
1420 |
1620 |
7 |
32 |
450 |
| 400 |
1250 |
1380 |
ten |
40 |
380 |
| 500 |
980 |
1140 |
fifteen |
52 |
310 |
| 600 |
750 |
900 |
20 |
60 |
250 |
Technological properties of steel 45ХН
| Forging temperature |
| Beginning 1200, end 800. Sections up to 250 mm are cooled in air, 251−350 mm — in a pit. |
| Weldability |
| difficult to weld. Welding method — RDS, heating and subsequent heat treatment are required. |
| Tendency to release ability |
| inclined |
| Flock sensitivity |
| hypersensitive |
Temperature of critical points of steel 45ХН
| Critical point |
° C |
| Ac1 |
750 |
| Ac3 |
790 |
| Mn |
310 |
Hardness of steel 45ХН
| Delivery condition, heat treatment mode |
HRC e surface |
HB |
| Cyanidation 810−830 С, oil. Vacation 200 C, air. |
59 |
450 |
| Hardening high-frequency voltage 850−870 C. Vacation 180−220 C. |
53−57 |
300 |
Endurance limit of steel 45ХН
| σ -1, MPa |
τ -1, MPa |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
| 594 |
892 |
1150 |
900 |
Quenching 845 C, water. Vacation 480 С, water. |
| 506 |
773 |
1010 |
810 |
Quenching 845 C, water. Vacation 590 С, water. |
Hardenability of steel 45ХН
Hardening 845 С. Hardness HRCэ.
| Distance from the end, mm / HRC e |
| 3 |
6 |
12 |
eighteen |
24 |
thirty |
36 |
42 |
| 57.5 |
57.5 |
57 |
56 |
53.5 |
50.5 |
48 |
44.5 |
| Heat treatment |
Crit. Diam. in oil, mm |
Crete. hardness, HRCэ |
| Tempering 830 C. Vacation 480 C. |
50 |
32−40 |
| Tempering 830 C. Vacation 370 C. |
50 |
38−47 |
Physical properties of steel 45ХН
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Density of steel, pn, kg / m 3 |
7820 |
|
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| Thermal conductivity coefficient W / (m ° С) |
|
45 |
43 |
41 |
40 |
|
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|
|
| 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) |
11.8 |
12.3 |
|
13.4 |
|
14.0 |
|
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