20NiCrMo13-4 1.6660 Case Hardening Steels
20NiCrMo13-4 1.6660 Case Hardening Steels
1. 1.6660 Application
• Gears subjected to high stresses, diverse parts subject to wear and fatigue in service.
• In the quenched and tempered condition: safety-critical parts.
Back to Top
2. 1.6660 Characteristics
• High mechanical properties.
• Good fatigue strength.
• After carburising, quenching and tempering, the surface hardness is around 730 HV.
• Good toughness of the carburised layer.
• For some carburising applications, oil quenching can be replaced with gas pressure quenching in order to minimise distortion due to the heat treatment.
Back to Top
3.All Grades Comparison
Back to Top
4.Quality Standard
EN 10084 2008 Case hardening steels
Back to Top
5. 1.6660 Chemical Composition(%)
| C | Mn | Si | P | S | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|
| 0.17-0.22 | 0.30-0.60 | 0.40 max | 0.025 max | 0.035 max | 0.80-1.20 | 3.00-3.50 | 0.30-0.50 |
Back to Top
6.Hardness requirements for products delivered in the conditions
| Process | Hardness |
|---|---|
| treated to improve shearability | 277HB max |
| soft annealed | 255HB max |
| treated to hardness range | 207HB-255HB |
| treated to ferrite-pearlite structure and hardness range | 197HB-241HB |
Back to Top
7.Conditions for heat treating test bars and treatment of the steels:
| Process | Temperatures (oC) |
|---|---|
| End quench test | 850 |
| Carburizing | 880-980 |
| Core-hardening | 825-880 |
| Case-hardening | 800-850 |
| Tempering | 150-250 |
Back to Top
8.Mill′s test certificate:
EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.
Back to Top
