Steel 40X9C2
40Cr9C2 Steel
Steel 40X9C2: Handbook of steels and alloys. Below is systematized information on the purpose, chemical composition, types of supply, substitutes, critical point temperatures, physical, mechanical, technological and foundry properties for the brand — Steel 40X9C2.
General information on steel 40X9C2
| Delivery type |
| Bar stock, including shaped: GOST 5949−75, GOST 2590−71, GOST 2591−71. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78. Grinded rod and silver GOST 14955−77. Strip GOST 4405−75, GOST 103−75. Forged and forged blanks GOST 1133−71. |
| Application |
| Inlet and outlet valves of automobile, tractor and diesel engines, recuperator tubes, heat exchangers, grates, fasteners. |
Chemical composition of steel 40Х9С2
| Chemical element |
% |
| Silicon (Si) |
2.0−3.0 |
| Manganese (Mn), not more |
0.8 |
| Copper (Cu), not more than |
0.30 |
| Nickel (Ni), not more than |
0.60 |
| Sulfur (S), not more than |
0.025 |
| Titanium (Ti), not more than |
0.2 |
| Carbon (C) |
0.35−0.45 |
| Phosphorus (P), not more than |
0.030 |
| Chrome (Cr) |
8.0−10.0 |
Mechanical properties of steel 40X9C2
Mechanical properties
| Heat treatment, delivery condition |
Section, mm |
σ0.2, MPa |
σB, MPa |
δ5, % |
ψ, % |
| Rods. Annealing at 850−870°C, air or without heat treatment |
60 |
440 |
740 |
15 |
35 |
| Quenching 900−1100°C, oil. Tempering 500−540°C, air. |
|
690 |
880 |
25 |
59 |
Mechanical properties at elevated temperatures
| t test,°C |
σ0, 2, MPa |
σB, MPa |
δ5, % |
ψ, % |
| Annealing at 850−870°C. |
| 20 |
640 |
880 |
20 |
58 |
| 200 |
550 |
820 |
18 |
64 |
| 300 |
520 |
780 |
18 |
63 |
| 400 |
450 |
780 |
18 |
62 |
| 500 |
410 |
590 |
17 |
65 |
| 600 |
390 |
520 |
17 |
80 |
| 700 |
170 |
215 |
18 |
92 |
| 800 |
49 |
78 |
22 |
99 |
| Specimen with a diameter of 10 mm and a length of 50 mm, rolled and annealed. Strain rate 1.1 mm/min, strain rate 0.0004 1/s. |
| 700 |
|
135 |
54 |
95 |
| 800 |
|
51 |
70 |
98 |
| 900 |
|
59 |
34 |
59 |
| 1000 |
|
45 |
29 |
45 |
| 1100 |
|
23 |
33 |
42 |
| 1200 |
|
16 |
71 |
74 |
Mechanical properties depending on tempering temperature
| t tempering temperature, °C |
σB, MPa |
δ5, % |
KCU, J/m2 |
HB |
| 1050 °C hardening, oil. |
| 300 |
2150 |
5 |
18 |
600 |
| 400 |
|
7 |
17 |
560 |
| 500 |
1470 |
11 |
16 |
410 |
| 600 |
1420 |
15 |
39 |
350 |
| 700 |
1280 |
18 |
69 |
300 |
| 800 |
1200 |
22 |
93 |
300 |
Technological properties of 40Х9С2 steel
| Forging temperature |
| Beginning temperature 1200, ending temperature 850. Sections up to 350 mm are cooled in furnaces. |
| Weldability |
| Not applicable for welded constructions |
| Tendency to temper |
| inclined |
| Flockability |
| is not sensitive |
Steel 40X9C2 critical point temperature
| Critical point |
°С |
| Ac1 |
900 |
| Ac3 |
970 |
| Ar3 |
970 |
| Ar1 |
810 |
Physical properties of 40X9C2 steel
| Test temperature,°C |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Steel density, pn, kg/m3 |
7630 |
7610 |
7580 |
|
7510 |
|
7440 |
|
7390 |
|
| Thermal conductivity coefficient W/(m — °C) |
|
17 |
|
20 |
|
|
22 |
|
22 |
|
| Test temperature,°C |
20−100 |
20−200 |
20−300 |
20−400 |
20−500 |
20−600 |
20−700 |
20−800 |
20−900 |
20−1000 |
| Coefficient of linear expansion (a, 10−6 1/°C) |
11.1 |
12.7 |
|
14.3 |
|
14.2 |
|
14.0 |
|
|
