Steel 40KH2N2MA
Description
Steel 40KH2N2MA
Steel 40Х2Н2МА: 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 40X2H2MA.
General information about steel 40X2H2MA
Substitute brand |
steel 38Х2Н2МА. |
Delivery type |
Long products, including shaped: GOST 4543−71, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78. Polished bar and silver bar GOST 14955−77. Strip GOST 103−76. Forgings and forged billets GOST 1133−71, GOST 8479−70. Pipes OST 14−21−77. |
Application |
Large products: shafts, discs, gears and fasteners. |
Chemical composition of 40Kh2N2MA steel
Chemical element |
% |
Silicon (Si) |
0.17−0.37 |
Manganese (Mn) |
0.30−0.60 |
Copper (Cu), no more |
0.30 |
Molybdenum (Mo) |
0.20−0.30 |
Nickel (Ni) |
1.35−1.75 |
Sulfur (S), no more |
0.025 |
Carbon (C) |
0.35−0.42 |
Phosphorus (P), no more |
0.025 |
Chromium (Cr) |
1.25−1.65 |
Mechanical properties of steel 40X2H2MA
Mechanical properties
Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
Bar. Hardening 870 ° С, oil. Vacation 600 ° C, water or oil. |
|
25 |
930 |
1080 |
ten |
45 |
78 |
|
Forgings. Hardening. Vacation |
KP 590 |
300−500 |
590 |
735 |
12 |
35 |
44 |
235−277 |
KP 640 |
300−500 |
640 |
785 |
eleven |
33 |
44 |
248−293 |
KP 735 |
<100 |
735 |
880 |
thirteen |
40 |
59 |
277−321 |
Mechanical properties depending on the tempering temperature
vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
HB |
Oil quenching. |
400 |
1230 |
1400 |
12 |
49 |
430 |
500 |
1090 |
1200 |
sixteen |
60 |
350 |
600 |
850 |
950 |
20 |
62 |
280 |
Mechanical properties depending on the section
Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 10 ,% |
KCU, J / m 2 |
Hire. Hardening 950 ° С, oil. Vacation 580−600 ° C. |
Sample cutting location — center |
500 |
760 |
930 |
fifteen |
57 |
Sample cutting location — edge |
500 |
770 |
960 |
17 |
53 |
The sample is cut in the center. Cross samples |
500 |
740 |
930 |
eleven |
23 |
The sample was cut out at the edge. Cross samples |
500 |
760 |
930 |
eleven |
22 |
Sample cutting location — center |
700 |
740 |
900 |
17 |
45 |
Sample cutting location — edge |
700 |
740 |
930 |
17 |
|
The sample is cut in the center. Cross samples |
700 |
790 |
900 |
|
fifteen |
The sample was cut out at the edge. Cross samples |
700 |
730 |
880 |
eleven |
27 |
Sample cutting location — center |
900 |
710 |
850 |
7 |
26 |
Sample cutting location — edge |
900 |
700 |
890 |
sixteen |
46 |
The sample is cut in the center. Cross samples |
900 |
690 |
730 |
|
20 |
The sample was cut out at the edge. Cross samples |
900 |
700 |
870 |
eleven |
24 |
Technological properties of steel 40X2H2MA
Forging temperature |
Beginning 1200, end 800. Sections up to 100 mm are cooled in air, 101−350 mm — in a pit. |
Weldability |
difficult to weld. Welding method: RDS. Heating and subsequent heat treatment is required. |
Tendency to release ability |
not inclined |
Flock sensitivity |
sensitive |
Temperature of critical points of steel 40X2H2MA
Critical point |
° C |
Ac1 |
740 |
Ac3 |
805 |
Impact strength of steel 40X2H2MA
Impact strength, KCU, J / cm 2
Delivery status, heat treatment |
+20 |
-20 |
-40 |
-60 |
Tempering 880 C, oil. Vacation 200 С, oil. |
50 |
41 |
36 |
35 |
Tempering 820 С, oil. Vacation 600 С, water |
139 |
122 |
128 |
125 |
b0.2 = 780 MPa, bw = 970 MPa, b5 = 20%, y = 61% |
120 |
|
105 |
85 |
Endurance limit of steel 40X2H2MA
σ -1, MPa |
n |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
520 |
|
|
1080 |
Tempering 890 C. Vacation 580 C, water. |
|
1E + 6 |
1200 |
|
|
Hardenability of steel 40Х2Н2МА
Tempering 845 C.
Distance from the end, mm / HRC e |
1.5 |
3 |
five |
nine |
thirteen |
20 |
25 |
thirty |
40 |
50 |
51.5−59 |
51.5−59 |
50.5−59 |
49.5−58 |
49.5−58 |
47.5−57 |
46.5−57 |
45.5−56 |
44.5−56 |
42.5−56 |
Amount of martensite,% |
Crit. Diam. in oil, mm |
50 |
115 |
90 |
100 |