Structural case-hardening steel 18CrNiMo7-6, 1.6587 for use on wheels and gears according to EN 10084, UNI 7846.
| Standards | Steel Grades | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical composition % | |||||||||||
| C: | Mn: | Si: | P: | S: | Cr: | Ni: | Mo: | Al: | Cu: | Pb: | |
| UNI 7846 UNI 8788 | 18NiCrMo5Pb | ||||||||||
| 0.15 - 0.21 | 0.6 - 0.9 | 0.15 - 0.40 | <0.035 | <0.035 | 0.7 - 1.0 | 1.2 - 1.5 | 0.15 - 0.25 | - | - | 0.15 - 0.30 | |
| UNI 8550 | 18NiCrMo5 | ||||||||||
| 0.15 - 0.21 | 0.6 - 0.9 | 0.15 - 0.40 | <0.035 | <0.035 | 0.7 - 1.0 | 1.2 - 1.5 | 0.15 - 0.25 | - | - | - | |
| UNI | 18NiCrMo7 | ||||||||||
| 0.17 - 0.22 | 0.45 - 0.65 | 0.15 - 0.40 | <0.035 | <0.035 | 0.4 - 0.7 | 1.6 - 2.0 | 0.2 - 0.3 | - | - | 0.15 - 0.30 | |
| PN | 17HNM | ||||||||||
| 0.14 - 0.19 | 0.4 - 0.7 | 0.17 - 0.37 | <0.035 | <0.035 | 1.5 - 1.8 | 1.4 - 1.7 | 0.25 - 0.35 | - | - | - | |
| EN | 18CrNiMo7-6 - 1.6587 - ZF1A | ||||||||||
| 0.15 - 0.21 | 0.5 - 0.9 | <0.40 | <0.025 | <0.035 | 1.5 - 1.8 | 1.4 - 1.7 | 0.25 - 0.35 | - | - | - | |
| EN | 17NiCrMo6-4 - 1.6566 | ||||||||||
| 0.14 - 0.20 | 0.6 - 0.9 | <0.4 | <0.025 | <0.035 | 0.8 - 1.1 | 1.2 - 1.5 | 0.15 - 0.25 | - | - | - | |
| DIN | 17CrNiMo6 | ||||||||||
| 0.15 - 0.21 | 0.5 - 0.9 | <0.4 | <0.025 | <0.035 | 1.5 - 1.8 | 1.4 - 1.7 | 0.25 - 0.35 | - | - | - | |
| BS | 822M17 - EN355 | ||||||||||
| 0.14 - 0.20 | 0.4 - 0.7 | - | <0.035 | <0.035 | 1.3 - 1.7 | 1.75 - 2.25 | 0.15 - 0.25 | - | <0.4 | - | |
| AFNOR | 18NiCrMo6 | ||||||||||
| 0.14 - 0.20 | 0.6 - 0.9 | 0.15 - 0.40 | <0.035 | <0.035 | 0.8 - 1.1 | 1.2 - 1.6 | 0.15 - 0.25 | - | - | - | |
Specification and application
Alloy steel 18CrNiMo7-6 is a grade consisting of the addition of chromium, nickel, molybdenum and coal with a range characteristic for all carburizing grades. 1.6587 materials, unlike other simple steel grades, can be used for much larger sizes and loads. This grade of steel is used for heavy-duty parts and components subjected to high pressures and highly variable speed of operation. Materials and derivatives are used for the production of special bearings, bolts, gears, shafts, or rack-and-pinions. They are related grades of steel according to UNI standards, having slightly narrowed content of Chromium, Nickel and Molybdenum.
Mechanical properties of 17NiCrMo6-4, 1.6566 steel
- Hardness in condition +A: < 229 HBW
- Hardness in condition +TH: 179 - 229 HBW
- Hardness in condition +FP: 149 - 201 HBW
- Hardness in condition +S: < 255 HBW
Mechanical properties of 18CrNiMo7-6, 1.6587 (ZF1A) steel
- Hardness in condition +A: < 229 HBW
- Hardness in condition +TH: 179 - 229 HBW
- Hardness in condition +TH: 179 - 229 HBW
- Hardness in condition +S: < 255 HBW
Mechanical properties of 17HNM steel
- Tensile strength, Rm: 1180 - 1420 MPa
- Yield point, Re: > 830 MPa
- Elongation, A: > 7%
- Contraction, Z: > 30%
- Hardness in softened state < 229 HB
Thermal and thermo-chemical treatment processes of 17HNM steel:
- Normalizing annealing at 870 - 900℃
- Softening annealing at 650 - 700℃
- Carburizing at 880 950℃
- Hardening (I) after carburization at the temperature of 840 - 870℃ in water or oil
- Annealing after carburization at 630 - 650℃
- Hardening (II) after carburization at 800 - 830℃ in water or oil
- Tempering after carburizing process at 170 - 200℃
- Carbonitriding at 860 - 930℃
In the above mentioned grades Rolex Metal supplies companies with:
Other 17HNM grade designations:
18CrNiMo7-6, 18CrNiMo7H, 18CrNiMo7HH, 18CrNiMo7HL, 17NiCrMo5, 17NiCrMo6, 17NiCrMo6, 17NiCrMo6-4, 17NiCrMoS6-4, 1.6587, 1.6566, 1.6569, X4317, 17CrNiMo7, 17 CrNiMo 7, 18 CrNiMo 7-6, 17 NiCrMo 5, 17 NiCrMo6, 17 NiCrMo 6-4, 17Cr2Ni2Mo, 17ChGN1M, 17ХГН1М, 17KhGN1M, 18Х2ГН2М, 18ХНМ, 18NiCrMo5, 18 NiCrMo 5, 17CrNiMo6, 17 CrNiMo 6, 18CND6, 18NCD6, 18 CND 6, 18 NCD 6, 16CrNiMo6, 16 CrNiMo 6, 822M17, 822 M 17, 815H17, 815 H 17, 815M17, 815 M 17, BNCMo1, 16Ni6Cr7Mo3, 18CrNiMo7, 18NiCrMo7, 18 NiCrMo 7, 18NiCrMo, 18MoNiCr17, C4520, 18 NiCrMo 6, 18NiCrMo6, 18NCD5, 18 NCD 5.