Steel 40ХН
Description
Steel 40ХН
Steel 40ХН: brand of steels and alloys. Below is the 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 40XN.
General information about steel 40ХН
Substitute brand |
Steel: 45ХН, 50ХН, 38ХГН, 40Х, 35ХГФ, 40ХНР, 40ХНМ, 30ХГВТ. |
Delivery type |
Circle 40xn, pipe 40xn, long products, including shaped: GOST 4543−71, GOST 259071, GOST 2591−71, GOST 2879−69, GOST 10702−78. Calibrated bar GOST 7417−75, GOST 8560−78, GOST 10702−78, GOST 4543−71. Polished bar and silver bar GOST 4543−71, GOST 14955−77. Thick sheet TU 14−1-1930−77. Strip GOST 103−76. Forgings and forged billets GOST 1133−71, GOST 8479−70, GOST 4543−71. Rolls OST 24.013.21−85. Pipes OST 14−21−77. |
Application |
Circle 40xn, axles, shafts, connecting rods, gear wheels, excavator shafts, couplings, pinion shafts, spindles, bolts, levers, rods, cylinders and other critical loaded parts subjected to vibration and dynamic loads, which are subject to increased strength and toughness requirements… Rolls of rail and structural steel mills for hot rolling of metal. |
Chemical composition of steel 40ХН
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) |
0.36−0.44 |
Phosphorus (P), no more |
0.035 |
Chromium (Cr) |
0.45−0.75 |
Mechanical properties of steel 40ХН
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 500 ° C, water or oil. |
|
25 |
785 |
980 |
eleven |
45 |
69 |
|
Forgings. Normalization |
KP 315 |
100−300 |
315 |
570 |
fourteen |
35 |
34 |
167−207 |
KP 315 |
300−500 |
315 |
570 |
12 |
thirty |
29 |
167−207 |
KP 315 |
500−800 |
315 |
570 |
eleven |
thirty |
29 |
167−207 |
Forgings. Hardening. Vacation. |
KP 345 |
300−500 |
345 |
590 |
fourteen |
38 |
49 |
174−217 |
KP 395 |
<100 |
395 |
615 |
17 |
45 |
59 |
187−229 |
KP 395 |
100−300 |
395 |
615 |
fifteen |
40 |
54 |
187−229 |
KP 395 |
300−500 |
395 |
615 |
thirteen |
35 |
49 |
187−229 |
KP 395 |
500−800 |
395 |
615 |
eleven |
thirty |
39 |
187−229 |
KP 440 |
<100 |
440 |
635 |
sixteen |
45 |
59 |
197−235 |
KP 440 |
100−300 |
440 |
635 |
fourteen |
40 |
54 |
197−235 |
KP 440 |
300−500 |
440 |
635 |
thirteen |
35 |
49 |
197−235 |
KP 440 |
500−800 |
440 |
635 |
eleven |
thirty |
39 |
197−235 |
KP 490 |
<100 |
490 |
655 |
sixteen |
45 |
59 |
212−248 |
KP 490 |
100−300 |
490 |
655 |
thirteen |
40 |
54 |
212−248 |
KP 540 |
<100 |
540 |
685 |
fifteen |
45 |
59 |
223−262 |
KP 540 |
100−300 |
540 |
685 |
thirteen |
40 |
49 |
223−262 |
KP 590 |
<100 |
590 |
735 |
fourteen |
45 |
59 |
235−277 |
KP 590 |
100−300 |
590 |
735 |
thirteen |
40 |
49 |
235−277 |
Mechanical properties at elevated temperatures
test t, ° C |
σ B, MPa |
δ 5 ,% |
ψ,% |
Normalization at 850 ° C. |
20 |
790 |
eighteen |
48 |
200 |
750 |
|
50 |
300 |
690 |
20 |
|
400 |
540 |
25 |
65 |
500 |
480 |
25 |
79 |
600 |
350 |
27 |
85 |
Sample 6 mm in diameter, 30 mm long, forged and normalized. The deformation rate is 50 mm / min, the deformation rate is 0.03 1 / s. |
700 |
225 |
36 |
92 |
800 |
130 |
57 |
96 |
900 |
91 |
71 |
100 |
1000 |
62 |
75 |
100 |
1100 |
45 |
76 |
100 |
1200 |
31 |
|
100 |
Mechanical properties depending on the tempering temperature
vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
Hardening 820 ° С, oil. |
400 |
1220 |
1370 |
ten |
41 |
32 |
387 |
500 |
1080 |
1160 |
fourteen |
51 |
46 |
302 |
600 |
760 |
910 |
20 |
60 |
83 |
241 |
Mechanical properties depending on the section
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
HB |
Normalization 870−925 ° С, hardening 790 ° С, oil. Vacation 540 ° C. |
40 |
780 |
960 |
eighteen |
58 |
325 |
80 |
730 |
920 |
20 |
54 |
302 |
120 |
710 |
910 |
|
50 |
300 |
Technological properties of steel 40ХН
Forging temperature |
Beginning 1250, end 830. Sections up to 50 mm are cooled in air, 50−200 mm — in a mold, 201−300 mm — with a furnace. |
Weldability |
difficult to weld. RDS, submerged-arc ADS, EShS. Heating and subsequent heat treatment are required. |
Machinability by cutting |
In the hot-rolled state at HB 166−170 and σ B = 690 MPa K υ tv.spl. = 1.0, K υ b.st. = 0.9. |
Tendency to release ability |
inclined |
Flock sensitivity |
hypersensitive |
Temperature of critical points of steel 40ХН
Critical point |
° C |
Ac1 |
735 |
Ac3 |
768 |
Ar3 |
700 |
Ar1 |
660 |
Mn |
305 |
Impact strength of steel 40ХН
Impact strength, KCU, J / cm 2
Delivery status, heat treatment |
+20 |
-20 |
-40 |
-60 |
Forging 200X30 mm. Hardening. Vacation. |
116 |
116 |
93 |
80 |
Endurance limit of steel 40ХН
σ -1, MPa |
τ -1, MPa |
n |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
490 |
294 |
|
980 |
780 |
HB 300−320 |
441 |
274 |
|
880 |
690 |
HB 270−300 |
392 |
235 |
|
780 |
570 |
HB 200−240 |
314−392 |
|
1E + 7 |
|
790 |
Normalization. HB 197. |
Hardenability of steel 40ХН
Hardness HRCэ.
Distance from the end, mm / HRC e |
1.5 |
3 |
4.5 |
6 |
nine |
12 |
fifteen |
21 |
27 |
33 |
52.5−58.5 |
51.5−58.0 |
49.5−57 |
48−56 |
41.5−54.5 |
35.5−49 |
32.5−43.5 |
28−37.5 |
26.5−33.5 |
26−31.5 |
Amount of martensite,% |
Crit. Diam. in water, mm |
Crit. Diam. in oil, mm |
Crete. hardness, HRCэ |
50 |
60−112 |
37−76 |
44−47 |
90 |
40−89 |
18−56 |
50−53 |
Physical properties of steel 40ХН
Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
Normal elastic modulus, E, GPa |
200 |
|
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Density of steel, pn, kg / m 3 |
7820 |
7800 |
7710 |
7840 |
7700 |
|
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Thermal conductivity coefficient W / (m ° С) |
|
44 |
43 |
41 |
39 |
37 |
|
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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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