R18 steel
P18 steel
Steel P18: 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 P18.
General information on steel R18
| Substitute for the brand |
| steel R12. |
| Kind of delivery |
| Rails Р18, circle Р18, strip Р18, square Р18, section rolled steel, including shaped: GOST 19265−73, GOST 2590−71, GOST 2591−71. Calibrated bar GOST 19265−73, GOST 7417−75. Grinded rod and silver GOST 19265−73, GOST 14955−77. Thick plate TU 14−1-1408−75. Sheet thin TU 14−1-1408−75, TU 14−1-1706−76. GOST 19265−73, GOST 4405−75. Wire TU. 14−1-1096−74. Forgings and forged blanks GOST 19265−73, GOST 1133−71. |
| Application |
| Chisels, drills, milling cutters, thread cutters, chisels, reamers, countersinks, taps, broaches for machining constructional steels with the strength to 1000 MPa, which require keeping the cutting properties when heated during operation up to 600 ° C. |
Chemical composition of steel R18
| Chemical element |
% |
| Vanadium (V) |
1.00−1.40 |
| Tungsten (W) |
17.0−18.5 |
| Cobalt (Co), not more than |
0.50 |
| Silicon (Si), not more than |
0.50 |
| Manganese (Mn), not more than |
0.50 |
| Molybdenum (Mo), not more than |
1.00 |
| Nickel (Ni), not more than |
0.40 |
| Sulfur (S), not more than |
0.03 |
| Carbon (C) |
0.73−0.83 |
| Phosphorus (P), max. |
0.03 |
| Chrome (Cr) |
3.80−4.40 |
Mechanical properties of R18 steel
Mechanical properties depending on tempering temperature
| t tempering temperature, °C |
σB, MPa |
KCU, J/m2 |
HRCe |
| Quenching at 1280 °C, oil. Tempering three times for 1 h. |
| 400 |
1370 |
23 |
61 |
| 500 |
1470 |
19 |
63 |
| 550 |
2350 |
17 |
66 |
| 600 |
2210 |
|
65 |
Technological properties of R18 steel
| Forging temperature |
| Beginning 1200, ending 900. Cooling in the wells at 750−800 C. |
| Weldability |
| The weldability is good when electrically joined with steel 45 and 40X. |
| Grindability |
| excellent (GOST 19265−73). |
The temperature of critical points of steel R18
| Critical point |
°С |
| Ac1 |
820 |
| Ac3 |
860 |
| Ar3 |
770 |
| Ar1 |
725 |
Physical properties of steel R18
| Test temperature,°C |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Modulus of normal elasticity, E, GPa |
228 |
223 |
219 |
210 |
201 |
192 |
181 |
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| Torsional shear modulus of elasticity G, GPa |
83 |
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| Steel density, pn, kg/m3 |
8800 |
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| Thermal conductivity coefficient W/(m — °C) |
|
26 |
27 |
28 |
29 |
28 |
27 |
27 |
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| Electrical resistivity (p, nominal value — m) |
419 |
472 |
544 |
627 |
718 |
815 |
922 |
1037 |
1152 |
1173 |
Heat resistance, red resistance of steel R18
Heat resistance
| Temperature, °C |
Time, h |
Hardness, HRCe |
| 620 |
4 |
59 |
