Steel 12ХН2А
Description
Steel 12ХН2А
Steel 12ХН2А: 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 12XN2A.
General information about steel 12ХН2А
Substitute brand |
steel: 20ХНР, 20ХГНР, 12ХН3А, 18ХГТ, 20ХGR. |
Delivery type |
Cellular products, including shaped: GOST 4543−71, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 1051−73, 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. Pipes GOST 8739−87, GOST 5732−78, GOST 9567−75, OST 14−21−77. |
Application |
Gears, shafts, worms, cam couplings, piston pins and other cemented parts that require high strength, ductility and toughness of the core and high surface hardness, operating under shock loads and at negative temperatures. |
Chemical composition of steel 12ХН2А
Chemical element |
% |
Silicon (Si) |
0.17−0.37 |
Manganese (Mn) |
0.30−0.60 |
Copper (Cu), no more |
0.30 |
Nickel (Ni) |
1.50−1.90 |
Sulfur (S), no more |
0.025 |
Carbon (C) |
0.09−0.16 |
Phosphorus (P), no more |
0.025 |
Chromium (Cr) |
0.60−0.90 |
Mechanical properties of steel 12ХН2А
Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
HRC e |
Bar. Hardening 860 ° C, water or oil. Zakakla 760−810 ° C, water or oil. Vacation 180 ° C, air or oil. |
fifteen |
590 |
780 |
12 |
50 |
88 |
|
|
Hot-deformed heat-treated pipes |
|
392 |
539 |
fourteen |
|
|
|
|
Cementation 920−950 ° C. Hardening 790−810 ° С, oil. Vacation 180−200 ° C, air. |
100 |
590 |
780 |
12 |
45 |
69 |
249 |
57−63 |
Cyanidation 840−860 ° C. Hardening 840−860 ° С, oil. Vacation 180−200 ° C, air. |
60 |
590 |
780 |
12 |
50 |
88 |
229 |
57 |
Mechanical properties depending on the section
Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
Hardening 880 ° С, oil. Vacation 600 ° C, water. |
Sample cutting location — center |
thirty |
420 |
550 |
29 |
79 |
363 |
Sample cutting location — center |
50 |
400 |
550 |
31 |
78 |
363 |
Sample cutting location — center |
100 |
370 |
510 |
thirty |
76 |
|
Sample cutting location — edge |
100 |
390 |
530 |
33 |
77 |
|
Hardening 880 ° C, through water to oil. Vacation 600 ° C, water. |
Sample cutting location — center |
50 |
450 |
600 |
28 |
77 |
363 |
Sample cutting location — center |
100 |
390 |
540 |
29 |
77 |
|
Sample cutting location — edge |
100 |
420 |
550 |
thirty |
77 |
|
Technological properties of steel 12ХН2А
Forging temperature |
Beginning 1250, end 800. Sections up to 100 mm are cooled in air, 101−300 mm — in a mold. |
Weldability |
restrictedly weldable. RDS, ADS under flux. |
Tendency to release ability |
inclined |
Flock sensitivity |
not sensitive |
Temperature of critical points of steel 12ХН2А
Critical point |
° C |
Ac1 |
715 |
Ac3 |
773 |
Ar3 |
726 |
Ar1 |
659 |
Mn |
405 |
Impact strength of steel 12ХН2А
Impact strength, KCU, J / cm 2
Delivery status, heat treatment |
+20 |
-40 |
-50 |
Section 30 mm. Guenching 860 C, oil. Vacation 530 С, water. |
353 |
323 |
206 |
Section 100 mm. Place of cutting of samples — edge. Tempering 880 C, oil. Vacation 530 С, water |
323 |
265 |
304 |
Section 100 mm. Place of cutting of samples — center. Tempering 880 C, oil. Vacation 530 С, water |
314 |
304 |
|
Section 10 mm. Gas carburizing 910 C, 3 h. Quenching 810 C, oil. Vacation 200 С, 1 h. |
49 |
8 |
|
Endurance limit of steel 12ХН2А
σ -1, MPa |
n |
σ B, MPa |
Heat treatment, steel condition |
323 |
1E + 6 |
740 |
Tempering 820 С, oil. Vacation 580 C. |
Hardenability of steel 12ХН2А
Hardening 900 C. Hardness HRCэ.
Distance from the end, mm / HRC e |
1.5 |
3 |
4.5 |
6 |
nine |
12 |
fifteen |
35.5 |
32 |
29 |
27 |
23 |
20 |
19 |
Amount of martensite,% |
Crit. Diam. in water, mm |
Crit. Diam. in oil, mm |
50 |
40 |
25 |
Physical properties of steel 12ХН2А
Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
Normal elastic modulus, E, GPa |
211 |
203 |
196 |
190 |
176 |
172 |
154 |
141 |
130 |
|
Torsional shear elastic modulus G, GPa |
95 |
80 |
76 |
71 |
69 |
67 |
60 |
55 |
50 |
|
Density of steel, pn, kg / m 3 |
7880 |
|
|
|
|
|
|
|
|
|
Thermal conductivity coefficient W / (m ° С) |
38 |
38 |
37 |
35 |
33 |
31 |
thirty |
29 |
29 |
|
Ud. electrical resistance (p, Nom. m) |
330 |
360 |
430 |
520 |
590 |
670 |
|
|
1050 |
1120 |
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) |
10.5 |
11.5 |
11.9 |
12.4 |
12.9 |
13.6 |
13.9 |
11.7 |
|
|
Specific heat (C, J / (kg ° C)) |
486 |
498 |
514 |
533 |
555 |
584 |
636 |
703 |
703 |
695 |