Steel 20KHGR
Description
Steel 20KHGR
Steel 20KHGR: 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 20HGR.
General information about steel 20HGR
| Substitute brand |
| Steel: 20ХН3А, 20ХН2М, 12ХН3А, 18ХГТ, 12ХН2. |
| Delivery type |
| Long products, including shaped: GOST 4543−71, GOST 259071, 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. |
| Application |
| Gears, Shaft — Gears, Worms, Cam Clutches, Pins, Pins, Bushings, and other upgradable or case hardened parts operating under shock loading conditions. |
Chemical composition of steel 20HGR
| Chemical element |
% |
| Boron (B) |
0.001−0.005 |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.70−1.00 |
| Copper (Cu), no more |
0.30 |
| Nickel (Ni), no more |
0.30 |
| Sulfur (S), no more |
0.035 |
| Carbon (C) |
0.18−0.24 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr) |
0.75−1.05 |
Mechanical properties of steel 20HGR
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
| Bar. Hardening 880 ° С, oil. Vacation 200 ° C, air or oil. |
fifteen |
780 |
980 |
nine |
50 |
78 |
Mechanical properties depending on the tempering temperature
| vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
| Hardening 880 ° С, oil. After tempering, cooling in oil. |
| 200 |
1220 |
1490 |
12 |
55 |
79 |
| 300 |
1230 |
1420 |
thirteen |
45 |
56 |
| 400 |
1160 |
1250 |
thirteen |
57 |
75 |
| 500 |
850 |
900 |
sixteen |
66 |
146 |
| 600 |
720 |
790 |
19 |
73 |
173 |
Technological properties of steel 20HGR
| Forging temperature |
| Beginning 1150, end 800. Sections over 75 mm are cooled slowly. |
| Tendency to release ability |
| not inclined |
| Flock sensitivity |
| not sensitive |
Temperature of critical points of steel 20HGR
| Critical point |
° C |
| Ac1 |
735 |
| Ac3 |
835 |
| Ar3 |
760 |
| Ar1 |
670 |
Impact strength of steel 20HGR
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
+20 |
0 |
-20 |
-40 |
-60 |
-80 |
| Guenching 860 C, oil. Vacation 200 С, oil. HRCе 46. |
61 |
60 |
61 |
62 |
60 |
61 |
| Guenching 860 C, oil. Vacation 500 С, oil. HRCэ 33. |
125 |
130 |
110 |
120 |
117 |
89 |
Hardness of steel 20HGR
| Delivery condition, heat treatment mode |
HRC e surface |
HB |
| Cementation 920−950 С, slow cooling or in grout boxes. Hardening 820−840 C, oil. Vacation 180−200 C, air or oil. |
57−63 |
321 |
Endurance limit of steel 20HGR
| σ -1, MPa |
τ -1, MPa |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
| 608 |
304 |
1150 |
1080 |
Section 55 mm, HB 340 |
| 510 |
304 |
980 |
870 |
Section 100 mm, HB 300 |
| 500 |
304 |
980 |
830 |
Section 150 mm, HB 286 |
Hardenability of steel 20HGR
Hardening 900 C. Hardness for strips of hardenability HRCe.
| Distance from the end, mm / HRC e |
| 1.5 |
3 |
4.5 |
6 |
nine |
12 |
fifteen |
eighteen |
21 |
24 |
| 37.5−47.5 |
37−47 |
36.5−46.5 |
35−46 |
31.5−44.5 |
26.5−43 |
23.5−40.5 |
38 |
35 |
33 |
| Amount of martensite,% |
Crit. Diam. in water, mm |
Crit. Diam. in oil, mm |
Crete. hardness, HRCэ |
| 50 |
75−97 |
46−64 |
33−35 |
| 90 |
38−68 |
16−40 |
40−42 |
Physical properties of steel 20HGR
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Normal elastic modulus, E, GPa |
207 |
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| Density of steel, pn, kg / m 3 |
7800 |
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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) |
11.7 |
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14.6 |
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