Steel 8X3
8Cr3 Steel
Steel 8X3: 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 grade — Steel 8X3.
General information on 8X3 steel
| Substitute for the brand |
| steel 7Х3. |
| Type of delivery |
| Sections, including shaped: GOST 5950−73, GOST 2590−71, GOST 2591−71. Calibrated bar GOST 5950−73, GOST 7417−75, GOST 8559−75, GOST 8560−78. Grinded rod and silversilver GOST 5950−73, GOST 14955−77. Strip GOST 5950−73, GOST 4405−75. Forged and forged blanks GOST 5950−74, GOST 1133−71, GOST 7831−78. |
| Application |
| The tool (punches, dies) hot upsetting the fastener and blanks of carbon and low-alloy constructional steels on the horizontal forging machines, parts of punches (dies. punches, ejectors) for hot pressing and extrusion, bending, trimming and punching dies. |
Chemical composition of steel 8X3
| Chemical element |
% |
| Vanadium (V), not more |
0.15 |
| Tungsten (W), not more |
0.20 |
| Silicon (Si) |
0.15−0.35 |
| Manganese (Mn) |
0.15−0.40 |
| Copper (Cu), not more |
0.30 |
| Molybdenum (Mo), max. |
0.20 |
| Nickel (Ni), not more than |
0.35 |
| Sulfur (S), not more than |
0.030 |
| Titanium (Ti), not more than |
0.03 |
| Carbon (C) |
0.75−0.85 |
| Phosphorus (P), not more than |
0.030 |
| Chrome (Cr) |
3.20−3.80 |
Mechanical properties of steel 8X3
Mechanical properties
| Heat treatment, delivery condition |
σ0.2, MPa |
σB, MPa |
δ5, % |
ψ, % |
KCU, J/m2 |
HRCe |
| Annealing at 650−700°C. Tempering at 820−850°C, oil. Tempering 480−550°C. |
1420−1520 |
1470−1570 |
6−9 |
18−20 |
20−24 |
44−48 |
Mechanical properties depending on tempering temperature
| t tempering temperature, °C |
σ0, 2, MPa |
σB, MPa |
δ5, % |
ψ, % |
KCU, J/m2 |
HRCe |
| Tempering at 870 °C, oil, tempering time 2 h. |
| 300 |
1800 |
1980 |
3 |
|
20 |
55 |
| 400 |
1630 |
1710 |
6 |
10 |
23 |
52 |
| 500 |
1270 |
1340 |
8 |
25 |
34 |
44 |
Mechanical properties as a function of test temperature
| t test temperature,°C |
σ0, 2, MPa |
σB, MPa |
δ5, % |
ψ, % |
KCU, J/m2 |
| Hardening at 870 °C in oil. Tempering at 500 °C, 2 h. |
| 200 |
1080 |
1270 |
8 |
27 |
46 |
| 300 |
1030 |
1220 |
10 |
28 |
54 |
| 400 |
930 |
1110 |
15 |
47 |
49 |
| 500 |
640 |
800 |
20 |
65 |
44 |
Technological properties of 8X3 steel
| Forging temperature |
| Beginning 1160, the end 800. Slow cooling in the wells. |
Steel 8X3 critical point temperature
| Critical point |
°С |
| Ac1 |
785 |
| Ac3 |
830 |
| Ar3 |
770 |
| Ar1 |
750 |
| Mn |
370 |
