Steel 20ХН
Description
Steel 20ХН
Steel 20ХН: a 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 20XN.
General information about steel 20ХН
| Substitute brand |
| Steel: 15ХР, 20ХНР, 18ХГТ. |
| 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 rod and silver 14955−77. Strip GOST 103−76. Forgings and forged billets GOST 1133−71. Pipes OST 14−21−77. |
| Application |
| Gears, bushings, pins, fasteners, and other parts that require high toughness and moderate hardenability. |
Chemical composition of steel 20ХН
| Chemical element |
% |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.40−0.70 |
| Copper (Cu), no more |
0.30 |
| Nickel (Ni) |
1.00−1.40 |
| Sulfur (S), no more |
0.035 |
| Carbon (C) |
0.17−0.23 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr) |
0.45−0.75 |
Mechanical properties of steel 20ХН
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 |
| Sample with a cross section of 10 mm. Hardening 850 ° С, oil. |
| 200 |
1050 |
1290 |
eleven |
48 |
90 |
62 |
| 300 |
1000 |
1220 |
|
50 |
80 |
60 |
| 400 |
910 |
1100 |
eleven |
51 |
75 |
|
| 500 |
770 |
950 |
fourteen |
54 |
110 |
|
| 600 |
650 |
770 |
20 |
60 |
180 |
|
Mechanical properties depending on the section
| Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
KCU, J / m 2 |
| Hardening 860 ° C, oil. Vacation 180 ° C. |
| 20 |
750 |
1130 |
ten |
85 |
| 40 |
600 |
990 |
ten |
90 |
| 80 |
520 |
870 |
ten |
90 |
| 100 |
510 |
860 |
ten |
90 |
Mechanical properties of the bar
| Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
| Hardening 860 ° C, water or oil. Hardening 760−810 ° C, water or oil. Vacation 180 ° C, water or oil. |
| fifteen |
590 |
780 |
fourteen |
50 |
78 |
Technological properties of steel 20ХН
| Forging temperature |
| Beginning 1250, end 830… Sections up to 50 mm are cooled in air, 50−100 mm — in a mold, 101−200 mm in a closed mold. |
| Weldability |
| restrictedly weldable. … |
| Tendency to release ability |
| inclined |
| Flock sensitivity |
| sensitive |
Temperature of critical points of steel 20ХН
| Critical point |
° C |
| Ac1 |
735 |
| Ac3 |
805 |
| Ar3 |
790 |
| Ar1 |
660 |
| Mn |
410 |
Impact strength of steel 20ХН
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
+400 |
+300 |
+200 |
+20 |
-20 |
-50 |
| Hardening, high tempering. |
68−72 |
91−94 |
44−46 |
81−89 |
62 |
43 |
Hardness of steel 20ХН
| Delivery condition, heat treatment mode |
HRC e surface |
HB |
| Normalization 860 C. Cementation 910 C, 16 hours to a depth of 1.6−1.8 mm. |
|
262−290 |
| Chilling in air up to 860 C, then oil. Tempering 770−780 C. Vacation 190 C. |
59−62 |
|
Endurance limit of steel 20ХН
| σ -1, MPa |
n |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
| 320 |
20E + 6 |
|
|
Sample 6 mm in diameter, smooth. Normalization 880C. Vacation 650−670 С. |
| 210 |
20E + 6 |
550 |
340 |
Spears 6 mm in diameter with a notch R = 1mm. HB 170 |
Hardenability of steel 20ХН
Hardness HRCэ.
| Distance from the end, mm / HRC e |
| 3 |
five |
ten |
fifteen |
20 |
25 |
thirty |
40 |
| 36.5−47.5 |
34−44.5 |
28−41 |
23−35.5 |
20.3−32 |
19−32 |
17.5−30 |
17.5−28 |
| Amount of martensite,% |
Crit. Diam. in water, mm |
Crit. Diam. in oil, mm |
Crete. hardness, HRCэ |
| 50 |
33−52 |
12−28 |
31−37 |
| 90 |
23−34 |
6−14 |
38−43 |
