17NiCrMo6-4 is a low carbon case hardening steel which has at least 0.8Cr%,1.2%Ni and 0.15%Mo as strengthening elements as per EN10084 standard.It is used for parts with a required core tensile strength of 1000 – 1300 N/mm² ,great surface hardness and also good wearing resistance.17NiCrMo6-4 is generally supplied in annealed condition with Max hardness 229HB.
1.Supply Form & Size & Tolerance
Hot rolled bar:Φ6-Φ130mm,Length:3000-10000mm
Hot Forged round bar:Φ130-Φ1000mm,Length:3000-10000mm
Flat bar/Blcoks:Thickness :120-800mm xWidth:120-1500mm,Length:2000-6000mm
| Surface Finish | Black-Forged | Black-Rolled | Turned | Grinding | Polished | Peeled | Cold Drawn |
| Tolerance | (0，+5mm) | (0，+1mm) | (0，+3mm) | Best h9 | Best h11 | Best H11 | Best H11 |
2.Chemical Composition
| Grade | C | Si | Mn | Cr | Ni | Mo | P | S |
| 17NiCrMo6-4/1.6566 | 0.14-0.2 | ≤ 0.4 | 0.6-0.9 | 0.8-1.1 | 1.2-1.5 | 0.15-0.25 | ≤ 0.025 | ≤ 0.035 |
| 17NiCrMoS6-4/1.6569 | 0.14-0.2 | ≤ 0.4 | 0.6-0.9 | 0.8-1.1 | 1.2-1.5 | 0.15-0.25 | ≤ 0.025 | 0.02-0.04 |
3.Relevant Standards
| UK | Italy | France | Sweden |
| 815M17 | 18NiCrMo5 | 18NCD6 | SS2523 |
4. Mechanical Property
| Hardening at 850°C,Tempering at 200°C | |||
| Size - mm | <16 | 16-40 | 40-100 |
| Tensile Strength, N/mm² | >1200 | >1000 | >900 |
| Hardness,HB | >359 | >298 | >271 |
5.Forging
17NiCrMo6-4 forging temperature:950 – 1200°C,cooled as slowly as possible in the furnace or in sand after forged.
6.Heat Treatment
- Normalizing: 870 – 890°C,Cooling in air
- Soft Annealing:650 – 700°C,Cooling in furnace
- Carburizing:880-980°C
- Core-hardening:830-870°C,oil-polymer salt bath
- Case-hardening:780-820°C,oil-polymer salt bath
- Tempering:150-200°C
7.Surface Hardness
- Treated to improveshearability(+S):Max 255HB
- Soft annealed(+A):Max 229HB
- Treated to hardness range(+TH):179-229HB
- Treated to ferrite-pearlite structure and hardness range(+FP):149-201HB
| Type | Distance mm | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 |
+H | HRC Min | 40 | 40 | 37 | 34 | 30 | 28 | 27 | 26 | 24 | 23 | 22 | 21 | - |
| HRC Max | 48 | 48 | 47 | 46 | 45 | 44 | 42 | 41 | 38 | 36 | 35 | 34 | 33 | |
+HH | HRC Min | 43 | 43 | 40 | 38 | 35 | 33 | 32 | 31 | 29 | 27 | 26 | 25 | 24 |
| HRC Max | 48 | 48 | 47 | 46 | 45 | 44 | 42 | 41 | 38 | 36 | 35 | 34 | 33 | |
+HL | HRC Min | 40 | 40 | 37 | 34 | 30 | 28 | 27 | 26 | 24 | 23 | 22 | 21 | - |
| HRC Max | 45 | 45 | 44 | 42 | 40 | 39 | 37 | 36 | 33 | 32 | 31 | 30 | 29 |
8.Application
17NiCrMo6-4 is widely used in automotive, chemical / petrochemical, earthmoving / agriculture industry,typical application:boxes, piston bolts, spindles, camshafts, gears, shafts and other mechanical controlling parts,especially in wheels and stopcock.
