Steel 40
Description
Steel 40
Steel 40: 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 Steel 40 grade.
General steel 40
| Substitute brand |
| steel: 35, 45, 40G |
| Delivery type |
| Sheet 40, circle 40, long products, including shaped: GOST 1050−74, GOST 2590−71, GOST 2591−71, GOST 2879−69, GOST 8509−86, GOST 8510−86, GOST 8239−72, GOST 8240−72, GOST 10702−78. Calibrated bar GOST 10702−78, GOST 7417−75, GOST 8559−75, GOST 8560−78. Polished bar and silver bar GOST 10702−78, GOST 14955−77. Thick sheet GOST 1577−81, GOST 19903−74, GOST 4041−71. Thin sheet GOST 16523−70. Tape GOST 10234−77, GOST 2284−79, GOST 1530−78. Strip GOST 103−76, GOST 82−70, GOST 1577−81. Wire GOST 17305−71, GOST 5663−79. Forgings and forged billets GOST 8479−70, GOST 1133−71. |
| Application |
| After improvement — crankshafts, connecting rods, gear rims, flywheels, gear wheels, bolts, axles and other parts; after surface hardening with HFC heating — parts of medium size, which are subject to the requirements of high surface hardness and increased wear resistance with low deformation (long shafts, travel rollers, gear wheels). |
Chemical composition of steel 40
| Chemical element |
% |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.50−0.80 |
| Copper (Cu), no more |
0.25 |
| Arsenic (As), no more |
0.08 |
| Nickel (Ni), no more |
0.25 |
| Sulfur (S), no more |
0.04 |
| Carbon (C) |
0.37−0.45 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr), no more |
0.25 |
Mechanical properties of steel 40
Mechanical properties at elevated temperatures
| test t, ° C |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
| Sample with a diameter of 6 mm and a length of 30 mm, rolled. The deformation rate is 16 mm / min. Strain rate 0.009 1 / s. |
| 700 |
99 |
140 |
48 |
85 |
| 800 |
70 |
110 |
53 |
97 |
| 900 |
54 |
71 |
55 |
100 |
| 1000 |
28 |
58 |
69 |
100 |
| 1100 |
24 |
37 |
60 |
100 |
| 1200 |
sixteen |
26 |
87 |
100 |
| 1300 |
12 |
eighteen |
56 |
100 |
Mechanical properties of rolled products
| Heat treatment, delivery condition |
Section, mm |
σ B, MPa |
δ 5 ,% |
δ 4 ,% |
ψ,% |
KCU, J / m 2 |
HB |
| Hot-rolled steel, forged calibrated and silver grade 2 after normalization |
25 |
570 |
19 |
|
45 |
59 |
|
| Calibrated steel grade 5 after work-hardening |
|
610 |
6 |
|
35 |
|
|
| Calibrated steel grade 5 after annealing or high tempering |
|
510 |
fourteen |
|
40 |
|
|
| Calibrated and calibrated steel with special finishing after tempering and annealing |
|
<590 |
|
|
40 |
|
197 |
| Heat-treated sheets of the 1st-2nd category |
4−14 |
510−650 |
21 |
|
|
|
167 |
| Normalized and hot rolled sheets |
80 |
560 |
20 |
|
|
|
|
| Annealed or highly tempered sheets |
80 |
520 |
21 |
|
|
|
|
| Normalized or hot rolled strips |
6−25 |
570 |
19 |
|
45 |
|
|
| Hot rolled sheet |
<2 |
510−660 |
|
sixteen |
|
|
|
| Hot rolled sheet |
2−3.9 |
510−660 |
|
17 |
|
|
|
| Cold rolled sheet |
<2 |
510−660 |
|
17 |
|
|
|
| Cold rolled sheet |
2−3.9 |
510−660 |
|
eighteen |
|
|
|
| Cold rolled annealed strip |
0.1−4 |
450−700 |
|
fourteen |
|
|
|
| Cold-rolled cold-worked strip, strength class H2 |
0.1−4 |
850−1050 |
|
|
|
|
|
| Annealed crimped tape |
0.1−4 |
<700 |
ten |
|
|
|
|
Mechanical properties of forgings
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
| Normalization |
| KP 215 |
300−500 |
215 |
430 |
eighteen |
40 |
44 |
123−167 |
| KP 215 |
500−800 |
215 |
430 |
sixteen |
35 |
39 |
123−167 |
| KP 245 |
100−300 |
245 |
470 |
19 |
42 |
39 |
143−179 |
| KP 245 |
300−500 |
245 |
470 |
17 |
35 |
34 |
143−179 |
| KP 275 |
<100 |
275 |
530 |
20 |
40 |
44 |
156−197 |
| KP 275 |
100−300 |
275 |
530 |
17 |
38 |
34 |
156−197 |
| Hardening. Vacation |
| KP 275 |
300−500 |
275 |
530 |
fifteen |
32 |
29 |
156−197 |
| KP 275 |
500−800 |
275 |
530 |
thirteen |
thirty |
29 |
156−197 |
| KP 315 |
100−300 |
315 |
570 |
fourteen |
35 |
34 |
167−207 |
| KP 345 |
<100 |
345 |
590 |
eighteen |
45 |
59 |
174−217 |
Mechanical properties depending on the tempering temperature
| vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
| 200 |
750 |
930 |
7 |
45 |
29 |
267 |
| 300 |
710 |
860 |
8 |
51 |
69 |
247 |
| 400 |
640 |
790 |
ten |
57 |
88 |
225 |
| 500 |
550 |
730 |
12 |
62 |
127 |
208 |
| 600 |
450 |
660 |
sixteen |
66 |
167 |
188 |
| 700 |
380 |
620 |
17 |
71 |
206 |
170 |
Technological properties of steel 40
| Forging temperature |
| Beginning 1250, end 800. Cooling of workpieces with a cross section up to 400 mm in air. |
| Weldability |
| Limited weldability. Methods of welding RDS, ADS submerged arc and gas shielded, EShS. Heating and subsequent heat treatment is recommended. KTS without restrictions. |
| Machinability by cutting |
| In the hot-rolled state at HB 170 and σ B = 520 MPa, K υ b.st. = 1.05, K υ tv.spl. = 1.2 |
| Tendency to release ability |
| Not inclined. |
| Flock sensitivity |
| Not sensitive. |
Temperature of critical points of steel 40
| Critical point |
° C |
| Ac1 |
730 |
| Ac3 |
890 |
| Ar3 |
780 |
| Ar1 |
690 |
| Mn |
340 |
Impact strength of steel 40
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
+20 |
-40 |
-80 |
| Quenching 850 С, water. Vacation 400 S. |
78 |
55 |
51 |
Endurance limit steel 40
| σ -1, MPa |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
| 231 |
520 |
275 |
Annealing 850 C. |
| 393 |
710 |
600 |
Quenching 845 C, water. Vacation 550 S. |
| 230 |
630 |
415 |
Tempering 845 C, oil. Vacation 430 C. |
Hardenability of steel 40
Hardening. Hardness for strips of hardenability, HRCэ (HRB).
| Distance from the end, mm / HRC e |
| 1.5 |
3 |
4.5 |
6 |
7.5 |
12 |
16.5 |
19.5 |
thirty |
| 50.5−58 |
45.5−57 |
39.5−52 |
26−37.5 |
24−34 |
(94) -29 |
(91) -27 |
(88) -26 |
(84) -23 |
| Heat treatment |
Amount of martensite,% |
Crit. Diam. in water, mm |
Crit. Diam. in oil, mm |
| Hardening |
50 |
15−25 |
8−15 |
| Hardening |
90 |
10−15 |
5−9.5 |
Physical properties of steel 40
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Normal elastic modulus, E, GPa |
212 |
206 |
201 |
192 |
176 |
163 |
151 |
131 |
118 |
|
| Torsional shear elastic modulus G, GPa |
82 |
80 |
78 |
75 |
68 |
63 |
58 |
50 |
45 |
|
| Density of steel, pn, kg / m 3 |
7850 |
|
|
|
|
|
|
|
|
|
| Thermal conductivity coefficient W / (m ° С) |
|
51 |
48 |
46 |
42 |
38 |
34 |
thirty |
25 |
26 |
| 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) |
11.9 |
12.8 |
13.5 |
14.1 |
14.6 |
14.9 |
15.2 |
12.5 |
13.5 |
14.5 |
| Specific heat (C, J / (kg ° C)) |
486 |
497 |
512 |
529 |
550 |
574 |
628 |
674 |
657 |
653 |