Steel 75
Description
Steel 75
Steel 75: 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 75 grade.
General steel 75
| Substitute brand |
| steel: 70, 80, 85. |
| Delivery type |
| Long products, including shaped: GOST 14959−79, GOST 2590−71, GOST 2591−71, GOST 2879−69, GOST 7419.0−78, GOST 7419.1−78, GOST 7419.3−78, GOST 7419.5−78 — GOST 7419.8 -78. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78. Polished bar and silver bar GOST 14955−77, GOST 7419.0−78, GOST 7419.1−78, GOST 7419.3−78, GOST 7419.5−78 — GOST 7419.8−78. Strip GOST 103−76, GOST 4405−75, GOST 82−70, GOST 7419.2−78, GOST 7419.4−78. Forgings and forged billets GOST 1133−71. |
| Application |
| round and flat springs of various sizes, car engine valve springs, shock absorber springs, springs, lock washers, clutch discs, eccentrics, spindles, shims and other parts operating under friction and under static and vibration loads. |
Chemical composition of steel 75
| Chemical element |
% |
| Silicon (Si) |
0.17−0.37 |
| Manganese (Mn) |
0.50−0.80 |
| Copper (Cu), no more |
0.20 |
| Nickel (Ni), no more |
0.25 |
| Sulfur (S), no more |
0.035 |
| Carbon (C) |
0.72−0.80 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr), no more |
0.25 |
Mechanical properties of steel 75
Mechanical properties
| Heat treatment, delivery condition |
Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
| Steel categories: 3.3A, 3B, 3V, 3G, 4.4A, 4B. Hardening 820 ° С, oil, tempering 470 ° С. |
Samples |
885 |
1080 |
nine |
thirty |
Technological properties of steel 75
| Forging temperature |
| Beginning 1180, end 800. Sections up to 220 mm are cooled in wells. |
| Weldability |
| not applicable for welded structures. KTS with subsequent heat treatment. |
| Tendency to release ability |
| not inclined |
| Flock sensitivity |
| insensitive |
Temperature of critical points of steel 75
| Critical point |
° C |
| Ac1 |
720 |
| Ac3 |
735 |
| Ar1 |
700 |
Endurance limit steel 75
| σ -1, MPa |
τ -1, MPa |
σ B, MPa |
σ 0.2, MPa |
Heat treatment, steel condition |
| 392 |
|
1080 |
880 |
|
| |
343−392 |
|
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Hardening 820 С, oil, tempering 480 С, air. |
Physical properties of steel 75
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Normal elastic modulus, E, GPa |
191 |
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| Torsional shear elastic modulus G, GPa |
78 |
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