Steel 40X
Description
Steel 40X
Steel 40X: 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 40X.
General information about steel 40X
Substitute brand |
steel: 45Х, 38ХА, 40ХН, 40ХС, 40ХФ, 40ХР. |
Delivery type |
Circle 40x, long products, including shaped: GOST 4543−71, GOST 2590−71, GOST 2591−71, GOST 2879−69, GOST 10702−78. Calibrated bar GOST 7414−75, GOST 8559−75, GOST 8560−78, GOST 1051−73. Polished bar and silver bar GOST 14955−77. Thick sheet GOST 1577−81, GOST 19903−74. Strip GOST 82−70, GOST 103−76, GOST 1577−81. Forgings and forged billets GOST 8479−70. Pipes GOST 8731−87, GOST 8733−87, GOST 13663−68. |
Application |
axles, shafts, pinion shafts, plungers, rods, crankshafts and camshafts, rings, spindles, mandrels, racks, gear rings, bolts, axle shafts, bushings and other improved parts of increased strength. |
Chemical composition of steel 40X
Chemical element |
% |
Silicon (Si) |
0.17−0.37 |
Manganese (Mn) |
0.50−0.80 |
Copper (Cu), no more |
0.30 |
Nickel (Ni), no more |
0.30 |
Sulfur (S), no more |
0.035 |
Carbon (C) |
0.36−0.44 |
Phosphorus (P), no more |
0.035 |
Chromium (Cr) |
0.80−1.10 |
Mechanical properties of steel 40X
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 860 ° C, oil. Vacation 500 ° C, water or oil |
25 |
780 |
980 |
ten |
45 |
59 |
|
Forgings. Normalization. KP 245 |
500−800 |
245 |
470 |
fifteen |
thirty |
34 |
143−179 |
Forgings. Normalization. KP 275 |
300−500 |
275 |
530 |
fifteen |
32 |
29 |
156−197 |
Forgings. Quenching, vacation. KP 275 |
500−800 |
275 |
530 |
thirteen |
thirty |
29 |
156−197 |
Forgings. Normalization. KP 315 |
<100 |
315 |
570 |
17 |
38 |
39 |
167−207 |
Forgings. Normalization. KP 315 |
100−300 |
315 |
570 |
fourteen |
35 |
34 |
167−207 |
Forgings. Quenching, vacation. KP 315 |
300−500 |
315 |
570 |
12 |
thirty |
29 |
167−207 |
Forgings. Quenching, vacation. KP 315 |
500−800 |
315 |
570 |
eleven |
thirty |
29 |
167−207 |
Forgings. Normalization. KP 345 |
<100 |
345 |
590 |
eighteen |
45 |
59 |
174−217 |
Forgings. Normalization. KP 345 |
100−300 |
345 |
590 |
17 |
40 |
54 |
174−217 |
Forgings. Quenching, vacation. KP 345 |
300−500 |
345 |
590 |
fourteen |
38 |
49 |
174−217 |
Forgings. Quenching, vacation. KP 395 |
<100 |
395 |
615 |
17 |
45 |
59 |
187−229 |
Forgings. Quenching, vacation. KP 395 |
100−300 |
395 |
615 |
fifteen |
40 |
54 |
187−229 |
Forgings. Quenching, vacation. KP 395 |
300−500 |
395 |
615 |
thirteen |
35 |
49 |
187−229 |
Forgings. Quenching, vacation. KP 440 |
<100 |
440 |
635 |
sixteen |
45 |
59 |
197−235 |
Forgings. Quenching, vacation. KP 440 |
100−300 |
440 |
635 |
fourteen |
40 |
54 |
197−235 |
Forgings. Quenching, vacation. KP 490 |
<100 |
490 |
655 |
sixteen |
45 |
59 |
212−248 |
Forgings. Quenching, vacation. KP 490 |
100−300 |
490 |
655 |
thirteen |
40 |
54 |
212−248 |
Mechanical properties at elevated temperatures
test t, ° C |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
Hardening 830 ° С, oil. Vacation 550 ° С, |
200 |
700 |
880 |
fifteen |
42 |
118 |
300 |
680 |
870 |
17 |
58 |
|
400 |
610 |
690 |
eighteen |
68 |
98 |
500 |
430 |
490 |
21 |
80 |
78 |
Sample 10 mm in diameter, 50 mm long forged and annealed. The deformation rate is 5 mm / min, the deformation rate is 0.002 1 / s. |
700 |
140 |
175 |
33 |
78 |
|
800 |
54 |
98 |
59 |
98 |
|
900 |
41 |
69 |
65 |
100 |
|
1000 |
24 |
43 |
68 |
100 |
|
1100 |
eleven |
26 |
68 |
100 |
|
1200 |
eleven |
24 |
70 |
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 850 ° C, water |
200 |
1560 |
1760 |
8 |
35 |
29 |
552 |
300 |
1390 |
1610 |
8 |
35 |
20 |
498 |
400 |
1180 |
1320 |
nine |
40 |
49 |
417 |
500 |
910 |
1150 |
eleven |
49 |
69 |
326 |
600 |
720 |
860 |
fourteen |
60 |
147 |
265 |
Mechanical properties depending on the section
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
Hardening 840−860 ° С, water, oil. Vacation 580−650 ° С, water, air. |
101−200 |
490 |
655 |
fifteen |
45 |
59 |
212−248 |
201−300 |
440 |
635 |
fourteen |
40 |
54 |
197−235 |
301−500 |
345 |
590 |
fourteen |
38 |
49 |
174−217 |
Technological properties of steel 40X
Forging temperature |
Beginning 1250, end 800. Sections up to 350 mm are cooled in air. |
Weldability |
difficult to weld. Welding methods: RDS, EShS. Heating and subsequent heat treatment are required. KTS — subsequent heat treatment is required. |
Machinability by cutting |
In the hot-rolled state at HB 163−168, σ B = 610 MPa K υ tv.spl. = 0.20, K υ b.st. = 0.95. |
Tendency to release ability |
inclined |
Flock sensitivity |
sensitive |
Temperature of critical points of steel 40X
Critical point |
° C |
Ac1 |
743 |
Ac3 |
815 |
Ar3 |
730 |
Ar1 |
693 |
Mn |
325 |
Impact strength of steel 40X
Impact strength, KCU, J / cm 2
Delivery status, heat treatment |
+20 |
-25 |
-40 |
-70 |
Hardening 850 С, oil. Vacation 650 S. |
160 |
148 |
107 |
85 |
Hardening 850 С, oil. Vacation 580 C. |
91 |
82 |
|
54 |
Endurance limit of steel 40X
σ -1, MPa |
τ -1, MPa |
n |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
363 |
|
1E + 6 |
690 |
|
|
470 |
|
1E + 6 |
940 |
|
|
509 |
|
|
960 |
870 |
|
333 |
240 |
5E + 6 |
690 |
|
|
372 |
|
|
|
|
Hardening 860 C, oil, tempering 550 C. |
Hardenability of steel 40X
Hardening 850 C. Hardness for hardenability strips HRCe.
Distance from the end, mm / HRC e |
1.5 |
4.5 |
6 |
7.5 |
10.5 |
13.5 |
16.5 |
19.5 |
24 |
thirty |
50.5−60.5 |
48−59 |
45−57.5 |
39−5-57 |
35−53.5 |
31.5−50.5 |
28.5−46 |
27−42.5 |
24.5−39.5 |
22−37.5 |
Heat treatment |
Amount of martensite,% |
Crit. Diam. in water, mm |
Crit. Diam. in oil, mm |
Crete. hardness, HRCэ |
Hardening |
50 |
38−76 |
16−48 |
43−46 |
|
90 |
23−58 |
6−35 |
49−53 |
Physical properties of steel 40X
Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
Normal elastic modulus, E, GPa |
214 |
211 |
206 |
203 |
185 |
176 |
164 |
143 |
132 |
|
Torsional shear elastic modulus G, GPa |
85 |
83 |
81 |
78 |
71 |
68 |
63 |
55 |
50 |
|
Density of steel, pn, kg / m 3 |
7850 |
|
7800 |
|
|
7650 |
|
|
|
|
Thermal conductivity coefficient W / (m ° С) |
41 |
40 |
38 |
36 |
34 |
33 |
31 |
thirty |
27 |
|
Ud. electrical resistance (p, Nom. m) |
278 |
324 |
405 |
555 |
717 |
880 |
1100 |
1330 |
|
|
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 |
12.2 |
13.2 |
13.7 |
14.1 |
14.6 |
14.8 |
12.0 |
|
|
Specific heat (C, J / (kg ° C)) |
466 |
508 |
529 |
563 |
592 |
622 |
634 |
664 |
|
|