Steel 15G
Description
Steel 15G
Steel 15G: 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 15G.
General information of steel 15G
| Substitute brand |
| steel 20G |
| Delivery type |
| long products, including shaped: GOST 4543−71, GOST 2590−71, GOST 2591−71, GOST 10702−78. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78, GOST 10702−78, GOST 1051−73. Polished bar and silver bar GOST 14955−77. Thick sheet GOST 1577−81, GOST 19903−74. Strip GOST 103−76, GOST 82−70, GOST 4543−71. Forgings and forged billets GOST 1133−71. |
| Application |
| after improvement — critical rivets; after carburizing or cyanidation — piston pins, friction discs, spring pins, cam rollers, bolts, nuts, screws, gears, worms and other parts with high surface hardness and wear resistance; without heat treatment — welded sub-engine frames, shoes, gussets, fittings, bushings. |
Chemical composition of steel 15G
| Chemical element |
% |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.70−1.00 |
| Copper (Cu), no more |
0.30 |
| Nickel (Ni), no more |
0.30 |
| Sulfur (S), no more |
0.035 |
| Carbon (C) |
0.12−0.19 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr), no more |
0.30 |
Mechanical properties of steel 15G
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
| Bar. Normalization 880 ° C, air. |
25 |
245 |
410 |
26 |
55 |
Mechanical properties depending on the tempering temperature
| vacation t, ° С |
σ 0.2, MPa |
σ B, MPa |
δ 10 ,% |
ψ,% |
KCU, J / m 2 |
| Billets with a diameter of 23 mm. Normalization 900 ° C. Hardening 890 ° C, water, cooling after tempering in oil. |
| 400 |
930 |
980 |
five |
65 |
59 |
| 450 |
780 |
870 |
8 |
70 |
108 |
| 550 |
640 |
700 |
12 |
78 |
118 |
Mechanical properties depending on the section
| Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 10 ,% |
ψ,% |
KCU, J / m 2 |
| Hardening 890 ° C, water. Vacation 425 ° C, oil. |
| 19 |
870 |
940 |
6 |
67 |
66 |
| 60 |
435 |
560 |
17 |
78 |
117 |
| Hardening 890 ° C, water. Vacation 450 ° C, oil. |
| 19 |
790 |
870 |
8 |
67 |
112 |
| 60 |
415 |
560 |
17 |
72 |
118 |
Technological properties of steel 15G
| Forging temperature |
| Beginning 1200, end 825. Air cooling. |
| Weldability |
| weldability is good. |
| Machinability by cutting |
| at HB 163, K υ tv.spl. = 1.6, K υ b.st. = 1.6 after annealing. |
| Tendency to release ability |
| not inclined |
| Flock sensitivity |
| not sensitive |
Temperature of critical points of steel 15G
| Critical point |
° C |
| Ac1 |
735 |
| Ac3 |
863 |
| Ar3 |
840 |
| Ar1 |
685 |
Impact strength of steel 15G
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
-20 |
| Sheets up to 80 mm thick, normalized and hot rolled |
29 |
Steel hardness 15G
| Delivery condition, heat treatment mode |
HRC e surface |
| Cementation 920−950 C. Hardening 810−830 C, water or oil. Vacation 180−200 C, air. |
57−63 |
| Cyanidation 840−860 C. Hardening 820−840 C, water or oil. Vacation 180−200 C, air. |
57−63 |
Hardenability of steel 15G
Cementation 915 C, 8 h. Oil quenching. End hardening 800 C. Hardness for strips of hardenability HRCe.
| Distance from the end, mm / HRC e |
| 1.5 |
3 |
4.5 |
6 |
7.5 |
nine |
10.5 |
| 65.5 |
61.5 |
50 |
45.5 |
44.5 |
43.5 |
43.5 |
Physical properties of steel 15G
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Normal elastic modulus, E, GPa |
|
186 |
183 |
|
|
|
|
|
|
|
| Density of steel, pn, kg / m 3 |
7810 |
|
|
|
|
|
|
|
|
|
| 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) |
12.3 |
|
13.2 |
|
|
14.9 |
|
|
|
|
| Specific heat (C, J / (kg ° C)) |
|
496 |
|
538 |
|
592 |
|
|
|
|
