Steel 50KHN
Description
Steel 50KHN
Steel 50ХН: a 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 50XN.
General information about steel 50ХН
| Substitute brand |
| steel 40ХН, 60ХГ. |
| Delivery type |
| Long products, including shaped: GOST 4543−71, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 10702−78, GOST 1051−73, GOST 7417−75, GOST 8559−75, GOST 8560−78. Polished bar and silver bar GOST 14955−77. Strip GOST 103−76. Forgings and forged billets GOST 1133−71. Rolls OST 24.013.21−5, OST 24.013.04−83. Pipes OST 14−21−77. |
| Application |
| Hot rolling rolls, pinion shafts, gear wheels, tires, crankshafts, connecting rods, bolts, exhaust valves and other large critical parts. |
Chemical composition of steel 50ХН
| 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) |
0.46−0.54 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr) |
0.45−0.75 |
Mechanical properties of steel 50ХН
Mechanical properties
| 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 |
885 |
1080 |
nine |
40 |
49 |
|
| Hardening 810−830 ° С, oil. Vacation 180−220 ° С, air. |
| 40 |
1470 |
1670 |
8 |
25 |
39 |
|
| Hardening 820 ° С, oil. Vacation 500 ° C, water or oil. |
| 60 |
780 |
980 |
nine |
40 |
49 |
269 |
| Hardening 820−840 ° С, oil. Vacation 550−600 ° C, water or oil. |
| 120 |
640 |
780 |
|
|
59 |
250−285 |
| Forging. Heating up to 1200 ° С, holding for 10 h, forging, isothermal annealing, normalization, high tempering. |
| 960 |
330 |
720 |
ten |
nine |
20 |
|
| 960 |
380 |
770 |
eighteen |
37 |
35 |
|
| Normalization 840−870 ° C, air. Vacation 580−630 ° С, oven. |
| 100−300 |
450 |
760 |
12 |
35 |
29 |
229−285 |
| 301−600 |
420 |
730 |
12 |
thirty |
25 |
223−269 |
| 601−900 |
390 |
690 |
eleven |
25 |
|
207−255 |
| 901−1200 |
340 |
670 |
ten |
20 |
|
201−241 |
Mechanical properties depending on the tempering temperature
| vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
HB |
| Hardening 800 ° C, oil. |
| 200 |
1520 |
1760 |
8 |
25 |
460 |
| 300 |
1420 |
1640 |
7 |
32 |
445 |
| 400 |
1220 |
1420 |
eleven |
41 |
385 |
| 500 |
980 |
1160 |
fourteen |
52 |
310 |
| 600 |
740 |
930 |
20 |
60 |
250 |
Mechanical properties versus test temperature
| 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 |
|
| 290 |
670 |
|
27 |
| 425 |
520 |
670 |
25 |
Technological properties of steel 50ХН
| Forging temperature |
| Beginning 1200, end 800. Sections up to 250 mm are cooled in air, 251−350 mm — in a pit. |
| Weldability |
| not applicable for welded structures (except for KTS). |
| Machinability by cutting |
| In the normalized and released state at HB 170−217 K υ tv.spl. = 0.7, K υ b.st. = 0.8. |
| Tendency to release ability |
| inclined |
| Flock sensitivity |
| sensitive |
Temperature of critical points of steel 50ХН
| Critical point |
° C |
| Ac1 |
735 |
| Ac3 |
755 |
| Ar3 |
690 |
| Ar1 |
660 |
| Mn |
300 |
Impact strength of steel 50ХН
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
-20 |
-60 |
| Billets with a cross section of 670 mm. Heating up to 1200 C, holding for 10 h, forging, isothermal annealing. Normalization, high vacation. |
16−43 |
8−22 |
Hardenability of steel 50ХН
Hardening 845 С. Hardness HRCэ.
| Distance from the end, mm / HRC e |
| 1.5 |
10.5 |
fifteen |
eighteen |
21 |
24 |
27 |
thirty |
33 |
39 |
| 57 |
57.5 |
57 |
56 |
54.5 |
53.5 |
52.5 |
51 |
49.5 |
46 |
Physical properties of steel 50ХН
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Density of steel, pn, kg / m 3 |
7860 |
|
|
|
|
|
|
|
|
|
| Thermal conductivity coefficient W / (m ° С) |
|
43 |
40 |
39 |
38 |
37 |
36 |
32 |
23 |
24 |
| 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 |
|
|
|
|
|
| Specific heat (C, J / (kg ° C)) |
500 |
510 |
560 |
630 |
700 |
800 |
910 |
650 |
610 |
700 |