Steel 40KHFA
Description
Steel 40KHFA
Steel 40HFA: 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 40HFA.
General information about steel 40HFA
Substitute brand |
Steel: 40X, 65G, 50XFA, 30X3MF. |
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 bar and silver bar GOST 14955−77. Strip GOST 103−76. Forgings and forged billets GOST 1133−71, GOST 8479−70. |
Application |
Improved condition — splined shafts, rods, set screws, traverses, excavator shafts and other parts operating at temperatures up to 400 ° C; after hardening and low tempering — worm shafts and other parts of increased wear resistance. |
Chemical composition of steel 40HFA
Chemical element |
% |
Vanadium (V) |
0.10−0.18 |
Silicon (Si) |
0.17−0.37 |
Manganese (Mn) |
0.50−0.80 |
Copper (Cu), no more |
0.30 |
Nickel (Ni), no more |
0.30 |
Sulfur (S), no more |
0.025 |
Carbon (C) |
0.37−0.44 |
Phosphorus (P), no more |
0.025 |
Chromium (Cr) |
0.8−1.1 |
Mechanical properties of steel 40HFA
Mechanical properties
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 880 ° С, oil. Vacation 650 ° C, water or oil |
|
25 |
730 |
880 |
ten |
50 |
88 |
|
|
Forgings. Hardening. Vacation. |
KP 395 |
100−300 |
395 |
615 |
fifteen |
40 |
54 |
187−229 |
|
KP 395 |
300−500 |
395 |
615 |
thirteen |
35 |
49 |
187−229 |
|
KP 490 |
100−300 |
490 |
655 |
thirteen |
40 |
54 |
212−248 |
|
KP 540 |
<100 |
540 |
685 |
fifteen |
45 |
59 |
223−262 |
|
KP 540 |
100−300 |
540 |
685 |
thirteen |
40 |
49 |
223−263 |
|
Bar. Hardening 860−880 ° С, oil. Vacation 200−230 ° С, oil. |
|
<40 |
1270 |
1570 |
|
35 |
39 |
|
49−53 |
Mechanical properties at elevated temperatures
test t, ° C |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
Hardening 850 ° С, oil. Vacation 640 ° С |
20 |
840 |
920 |
26 |
63 |
200 |
800 |
900 |
22 |
46 |
300 |
740 |
840 |
eighteen |
35 |
400 |
710 |
850 |
28 |
50 |
500 |
400 |
490 |
thirty |
65 |
600 |
|
370 |
51 |
80 |
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 850 ° С, oil. Cooling after tempering from 500 ° C in water. |
200 |
1490 |
1860 |
fourteen |
43 |
49 |
51 |
300 |
1450 |
1650 |
fifteen |
thirty |
thirty |
49 |
400 |
1270 |
1360 |
fourteen |
39 |
39 |
46 |
500 |
1100 |
1160 |
fifteen |
61 |
61 |
42 |
600 |
880 |
960 |
19 |
98 |
98 |
34 |
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 850 ° C, water. Vacation 600 ° C, air. (Samples are tangential) |
Sample cutting location — center |
50 |
900 |
940 |
fifteen |
45 |
69 |
Sample cutting location — center |
80 |
810 |
890 |
eleven |
33 |
39 |
Sample cutting location — center |
120 |
710 |
860 |
12 |
37 |
64 |
Sample cutting location — center |
160 |
610 |
830 |
fifteen |
46 |
45 |
Sample cutting place — 1 / 2R |
160 |
710 |
850 |
sixteen |
44 |
47 |
Sample cutting location — center |
200 |
490 |
710 |
17 |
49 |
57 |
Sample cutting place — 1 / 2R |
200 |
510 |
800 |
eighteen |
49 |
47 |
Sample cutting location — center |
240 |
490 |
710 |
eighteen |
51 |
71 |
Sample cutting place — 1 / 2R |
240 |
570 |
770 |
19 |
50 |
54 |
Sample cutting location — edge |
240 |
700 |
830 |
17 |
49 |
61 |
Technological properties of steel 40HFA
Forging temperature |
The beginning is 1250, the end is 860−800. Sections up to 200 mm are cooled in a mold, 201−300 mm — with a furnace. |
Weldability |
difficult to weld. Welding methods: RDS — heating and subsequent heat treatment are required. KTS — subsequent heat treatment is required. |
Machinability by cutting |
After quenching and tempering at HB? 241, K υ tv.spl. = 0.75, K υ b.st. = 0.65. |
Tendency to release ability |
inclined |
Flock sensitivity |
sensitive |
Temperature of critical points of steel 40HFA
Critical point |
° C |
Ac1 |
760 |
Ac3 |
800 |
Ar3 |
725 |
Ar1 |
680 |
Mn |
214 |
Impact strength of steel 40HFA
Impact strength, KCU, J / cm 2
Delivery status, heat treatment |
+20 |
-20 |
-70 |
Ordering 850 С, oil. Vacation 600 C. |
92 |
61 |
55 |
Endurance limit of steel 40HFA
σ -1, MPa |
τ -1, MPa |
n |
σ B, MPa |
Heat treatment, steel condition |
480 |
|
1E + 6 |
1220 |
Tempering 880 C, oil. Vacation 230 S. NV 387 |
421 |
|
1E + 6 |
990 |
Tempering 880 C, oil. Vacation 550 S. NV 288 |
372 |
265 |
1E + 6 |
960 |
Tempering 880 C, oil. Vacation 650 S. NV 258 |
Hardenability of steel 40HFA
Hardness, HRC
Distance from the end, mm / HRC e |
1.5 |
3 |
4.5 |
6 |
nine |
12 |
fifteen |
eighteen |
27 |
39 |
51.5−60.5 |
51.5−59.5 |
50.5−58.5 |
48−57.5 |
39.5−54 |
35−50.5 |
34−46.5 |
32.5−43 |
30.5−39 |
27−39 |
Physical properties of steel 40HFA
Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
Normal elastic modulus, E, GPa |
215 |
212 |
205 |
199 |
182 |
173 |
166 |
144 |
135 |
|
Torsional shear elastic modulus G, GPa |
84 |
83 |
80 |
77 |
71 |
66 |
64 |
56 |
52 |
|
Density of steel, pn, kg / m 3 |
7810 |
|
|
|
|
|
|
|
|
|
Thermal conductivity coefficient W / (m ° С) |
37 |
37 |
37 |
36 |
33 |
31 |
31 |
thirty |
28 |
|
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) |
12.1 |
12.6 |
13.0 |
13.3 |
13.8 |
14.2 |
14.6 |
11.8 |
|
|
Specific heat (C, J / (kg ° C)) |
466 |
508 |
529 |
563 |
592 |
621 |
634 |
664 |
|
|