Steel 38XA
Description
Steel 38XA
Steel 38XA: 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 brand — Steel 38XA.
General information about steel 38XA
Substitute brand |
steel: 40X, 35X, 40XH. |
Delivery type |
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. Forgings and forged billets GOST 1131−71. |
Application |
worms, gear wheels, gears, shafts, axles, critical bolts and other upgradable parts. |
Chemical composition of steel 38XA
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 |
0.025 |
Carbon (C) |
0.35−0.42 |
Phosphorus (P), no more |
0.025 |
Chromium (Cr) |
0.80−1.10 |
Mechanical properties of steel 38XA
Mechanical properties
Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
Bar. Hardening 860 ° C, oil. Vacation 550 ° C, water or oil |
25 |
780 |
930 |
12 |
50 |
88 |
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. |
400 |
1220 |
1310 |
7 |
38 |
54 |
380 |
500 |
930 |
1030 |
12 |
47 |
108 |
320 |
600 |
710 |
830 |
17 |
63 |
167 |
260 |
Mechanical properties depending on the section
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
Forgings. Hardening 850 ° С, oil. Vacation 560 ° С, air. |
100 |
540 |
690 |
fifteen |
45 |
59 |
240−280 |
100−200 |
490 |
660 |
thirteen |
40 |
54 |
230−270 |
200−300 |
440 |
640 |
fourteen |
40 |
54 |
230−260 |
Mechanical properties versus test temperature
test t, ° C |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
Bar with a diameter of 28−55 mm. Hardening 850 ° С, oil. Vacation 550 ° С, 3 h. |
20 |
790 |
940 |
thirteen |
55 |
83 |
285−302 |
300 |
680 |
880 |
17 |
58 |
|
|
400 |
610 |
690 |
eighteen |
68 |
98 |
|
500 |
430 |
490 |
21 |
80 |
78 |
|
Bar with a diameter of 28−55 mm. Hardening 830 ° С, oil. Vacation 680 ° С, 3 h. |
20 |
570 |
700 |
26 |
60 |
216 |
207−217 |
400 |
430 |
590 |
19 |
71 |
211 |
|
500 |
360 |
420 |
24 |
79 |
132 |
|
600 |
210 |
245 |
32 |
89 |
|
|
Bar with a diameter of 25 mm. Hardening 860 ° C, oil. Vacation 550 ° C. |
-20 |
900 |
1040 |
eighteen |
58 |
|
|
-40 |
930 |
1100 |
eighteen |
55 |
78 |
|
-70 |
1000 |
1120 |
eighteen |
55 |
59 |
|
Technological properties of steel 38XA
Forging temperature |
Beginning 1240, end 780. |
Weldability |
difficult to weld, fusion welding with preheating followed by heat treatment is recommended. |
Machinability by cutting |
σ B = 930 MPa 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 38XA
Critical point |
° C |
Ac1 |
740 |
Ac3 |
780 |
Ar3 |
730 |
Ar1 |
693 |
Mn |
250 |
Endurance limit of steel 38XA
σ -1, MPa |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
333 |
690 |
|
Hardening. Vacation. |
392 |
980 |
830 |
HB 241 |
372 |
870 |
|
|
Hardenability of steel 38XA
Hardness for strips HRCe.
Distance from the end, mm / HRC e |
2.5 |
five |
7.5 |
12.5 |
fifteen |
20 |
25 |
35 |
51.5−60 |
49.5−59 |
44.5−57.5 |
34.5−51 |
32.5−47.5 |
31−42.5 |
30−39 |
28−37.5 |
Physical properties of steel 38XA
Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
Normal elastic modulus, E, GPa |
196 |
|
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Torsional shear elastic modulus G, GPa |
83 |
|
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Density of steel, pn, kg / m 3 |
7850 |
|
7800 |
|
|
|
7650 |
|
|
|
Thermal conductivity coefficient W / (m ° С) |
|
50 |
46 |
42 |
40 |
37 |
35 |
31 |
|
|
Ud. electrical resistance (p, Nom. m) |
290 |
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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) |
12.7 |
13.1 |
13.5 |
13.8 |
14.2 |
14.6 |
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