Steel with chromium, nickel, and molybdenum, suitable for pieces of a complex shape with good core tenacity.
Standard Reference: EN ISO 683-3: 2018 (Hot-rolled) | EN 10277: 2018 (Bright products)
| EUROPE | ITALY | GERMANY | FRANCE | UK | USA | ||||
|---|---|---|---|---|---|---|---|---|---|
| EN 10084: 2008 EN 10277-4: 2008 |
(UNI 7846-78) | (DIN 17210-84) | (NFA35-551-86) | (BS970 pt.1--96) | ASTM A 29 | ||||
| Grade | N° | Werkstoff | N° | - | |||||
| 20NiCrMo2-2 | 1.6523 | 20NiCrMo2 | 21NiCrMo2 | 1.6523 | 20NCD2 | 805M20 | 8620 | ||
| 20NiCrMoS2-2 | 1.6526 | 21NiCrMoS2 | 1.6526 | ||||||
| EUROPE | C | Si | Mn | P/max | S | Cr | Mo | Ni | Cu/max | Al |
|---|---|---|---|---|---|---|---|---|---|---|
| 20NiCrMo2-2 | 0,17÷0,23 | 0,15÷0,40 | 0,65÷0,95 | 0,025 | ≤0,035 | 0,35÷0,70 | 0,15÷0,25 | 0,40÷0,70 | 0,40 | 0,020÷0,050 |
| 20NiCrMoS2-2 | 0,020÷0,040 | |||||||||
| Hardness (HB) Treated to improve sherability (+S) |
Hardness (HB) Annealed to max. hardness requirements (+A) |
Hardness (HB) Treated to hardness range (+TH) |
Hardness (HB) Treated to ferrite-pearlite structure and hardness range (+FP) |
|||||
|---|---|---|---|---|---|---|---|---|
| ( ≤ 255 ) | ≤ 212 | ≥ 161 | ≤ 212 | ≥ 149 | ≤ 194 | |||
| Size (mm) |
+A*+ Turned (+A +SH) |
+A*+ Cold drawn (+A+C) |
FP**+ Turned (+FP +SH) |
FP**+ Cold drawn (+FP +C) |
|||
|---|---|---|---|---|---|---|---|
| Hardness HB max |
Hardness HB max |
Hardness HB |
Hardness HB |
||||
| 5≤d≤10 | - | 270 | - | - | |||
| 10<d≤16 | - | 260 | - | - | |||
| 16<d≤40 | 212 | 255 | 149÷194 | 149÷240 | |||
| 40<d≤63 | 212 | 255 | 149÷194 | 149÷240 | |||
| 63<d≤100 | 212 | 255 | 149÷194 | 149÷240 | |||
| *+A = Annealed to maximum hardness requirement. **+FP = Treated to ferrite-perlite structure and hardness range. Note: For size <5 mm the mechanical properties may be agreed at the time of enquiry and order. |
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| Operation | °C |
|---|---|
| Hot forgings deformation | 900÷1150 |
| Carburizing temperature | 880÷980 |
| Core quenching temperature | 860÷900 |
| Case quenching temperature | 780÷820 |
| Tempering | 150÷200 |
| Limits of range | Hardness HRC at a distance from quenched end of test pieces (mm) | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1,5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 | |||||||
| +H | Max | 49 | 48 | 45 | 42 | 36 | 33 | 31 | 30 | 27 | 25 | 24 | 24 | 23 | |||||
| Min | 41 | 37 | 31 | 25 | 22 | 20 | - | - | - | - | - | - | - | ||||||
| +HH | Max | 49 | 48 | 45 | 42 | 36 | 33 | 31 | 30 | 27 | 25 | 24 | 24 | 23 | |||||
| Min | 44 | 41 | 36 | 31 | 27 | 24 | 22 | 21 | - | - | - | - | - | ||||||
| +HL | Max | 46 | 44 | 40 | 36 | 31 | 29 | 27 | 26 | 23 | 21 | 20 | 20 | - | |||||
| Min | 41 | 37 | 31 | 25 | 22 | 20 | - | - | - | - | - | - | - | ||||||
