Steel 20ХНР
Description
Steel 20ХНР
Steel 20KHNR: 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 20ХНР.
General information about steel 20ХНР
| Substitute brand |
| steel 20ХН. |
| Delivery type |
| Long products, including shaped: GOST 4543−71, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 4543−71, GOST 7417−75, GOST 8559−75, GOST 8560−78. Polished bar and silver bar GOST 4543−71, GOST 14955−77. Strip GOST 103−76. Forgings and forged billets GOST 4543−71, GOST 1133−71. |
| Application |
| Gears, pinion shafts, worms, clutches, rollers, pins, bushings and other loaded large parts operating under shock loading conditions. |
Chemical composition of steel 20ХНР
| Chemical element |
% |
| Boron (B) |
0.001−0.005 |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.60−0.90 |
| Copper (Cu), no more |
0.30 |
| Nickel (Ni) |
0.80−1.10 |
| Sulfur (S), no more |
0.035 |
| Titanium (Ti), no more |
0.06 |
| Carbon (C) |
0.16−0.23 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr) |
0.70−1.10 |
Mechanical properties of steel 20ХНР
Mechanical properties depending on the tempering temperature
| vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HRC e |
| Hardening 860 ° C, oil. Cooling after tempering in oil. |
| 200 |
1220 |
1520 |
ten |
54 |
49 |
47 |
| 300 |
1200 |
1400 |
|
|
49 |
46 |
| 400 |
1180 |
1250 |
eleven |
57 |
69 |
43 |
| 500 |
880 |
980 |
fourteen |
64 |
127 |
34 |
| 600 |
740 |
780 |
sixteen |
65 |
172 |
28 |
Mechanical properties depending on the section
| Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
| Normalization 930 ° C, air. Hardening 840 ° С, oil. Vacation 200 ° C, air. |
| 25 |
1370 |
1420 |
fourteen |
60 |
108 |
418 |
| 50 |
1110 |
1200 |
|
62 |
147 |
340 |
| 75 |
970 |
1060 |
fifteen |
60 |
108 |
302 |
| 100 |
920 |
1000 |
fifteen |
60 |
127 |
302 |
| 150 |
830 |
1000 |
sixteen |
|
98 |
286 |
Mechanical properties of the bar
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
| Normalization 930−950 ° C, air. Hardening 780−830 ° С, oil. Vacation 200 ° C, air or oil. |
fifteen |
980 |
1180 |
ten |
50 |
88 |
Technological properties of steel 20ХНР
| Forging temperature |
| Beginning 1150, end 800. |
| Weldability |
| RDS. Heating and subsequent heat treatment is recommended. |
| Tendency to release ability |
| inclined |
| Flock sensitivity |
| sensitive |
Temperature of critical points of steel 20ХНР
| Critical point |
° C |
| Ac1 |
740 |
| Ac3 |
830 |
| Ar3 |
725 |
| Ar1 |
650 |
Impact strength of steel 20ХНР
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
+20 |
-20 |
-40 |
-60 |
| Guenching 860 C, oil. Vacation 200 С, oil, HRCе 47 |
61 |
61 |
62 |
60 |
| Guenching 860 C, oil. Vacation 500 С, oil. HRCэ 33 |
125 |
110 |
120 |
117 |
Hardness of steel 20ХНР
| Delivery condition, heat treatment mode |
HRC e surface |
HRC e core |
| Cementation 930 C, slow cooling in wells or boxes. Hardening 820−840 C, oil. Vacation 180−200 C, air. |
57−63 |
37−47 |
Endurance limit of steel 20ХНР
| σ -1, MPa |
n |
σ B, MPa |
Heat treatment, steel condition |
| 578 |
1E + 6 |
470 |
Normalization 930 C, hardening 840 C, oil. Vacation 200 C. |
Hardenability of steel 20ХНР
Hardening 860 C. Hardness for strips of hardenability HRCe.
| Distance from the end, mm / HRC e |
| 1.5 |
3 |
4.5 |
6 |
nine |
12 |
fifteen |
21 |
27 |
239 |
| 43−48.5 |
43.5−49 |
43−49.5 |
42.5−49.5 |
41−49.5 |
39.5−49 |
38−48.5 |
35−47.5 |
31−45 |
26−40 |
| Heat treatment |
Amount of martensite,% |
Crit. Diam. in oil, mm |
Crete. hardness, HRCэ |
| Tempering 880 C, oil. |
50 |
38 |
39 |
