Steel similar to 25CrMo4. The greater carbon content makes welding more difficult, but favors temperability.
Standard Reference: UNI 7845-78 (Hot-rolled products)
| EUROPE | ITALY | GERMANY | FRANCE | UK | USA | ||
|---|---|---|---|---|---|---|---|
|
EN 10083-3: 2006 |
(UNI 7845-78) | (DIN 17200-86) | (NF A 35-552-86) | (BS 970 pt.3-96) | ASTM A 29 | ||
| Grade | N° | Werkstoff | N° | ||||
| - | - | 30CrMo4 | - | - | 30CD4 | - | - |
| C | Si | Mn | P/max | S/max | Cr | Mo | Al |
|---|---|---|---|---|---|---|---|
| 0,27÷0,34 | 0,15÷0,40 | 0,40÷0,70 | 0,035 | 0,035 | 0,80÷1,10 | 0,15÷0,25 | 0,020÷0,050 |
| Size (mm) |
Treated to improve shearability (+S) |
Soft annealing (+A) |
Quenched and tempered (+QT) |
|||
|---|---|---|---|---|---|---|
| HB max to condition | Rp0,2 (MPa) min |
Rm (MPa) min |
A5 (%) min |
KCU (J) min |
||
| d≤16 | 255 | 220 | 685 | 880÷1080 | 12 | 32,5 |
| 16<d≤40 | 255 | 220 | 635 | 830÷1030 | 12 | 32,5 |
| 40<d≤100 | 255 | 220 | 520 | 740÷880 | 13 | 30 |
| 100<d≤160 | 255 | 220 | 420 | 690÷830 | 15 | 30 |
| *For reference only. | ||||||
| Size (mm) |
as Rolled+Turned (+A+SH) |
Quenched+Tempered+Turned (+QT+SH)* |
Quenched+Tempered+Cold Drawn (+QT+C) |
as Rolled+Cold Drawn (+A+C) |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Hardness HB max |
Rp0,2 (MPa) min |
Rm (MPa) min |
A5 (%) min |
Rp0,2 (MPa) min |
Rm (MPa) | A5 (%) min |
Hardness HB max |
||||
| 5≤d≤10 | - | - | - | - | 700 | 900÷1100 | 8 | 280 | |||
| 10<d≤16 | - | - | - | - | 700 | 900÷1100 | 8 | 270 | |||
| 16<d≤40 | 220 | 635 | 830÷1030 | 12 | 620 | 830÷1030 | 9 | 265 | |||
| 40<d≤63 | 220 | 520 | 740÷880 | 13 | 550 | 740÷880 | 10 | 260 | |||
| 63<d≤100 | 220 | 520 | 740÷880 | 13 | 480 | 740÷880 | 11 | 260 | |||
| *This values are valid also for Cold Drawn - Quenched + Tempered Condition (+C +QT). Note: For size <5 mm the mechanical properties may be agreed at the time of enquiry and order. |
|||||||||||
| Operation | °C |
|---|---|
| Hot forgings deformation | 850÷1150 |
| Isothermal annealing | 840÷880-->650 |
| Soft annealing | 680÷720 |
| Quenching in water or oil | 850÷870 |
| Tempering | 550÷650 |
| 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 | 45 | 50 | |||||||
| +H | Max | 56 | 55 | 53 | 51 | 49 | 47 | 45 | 42 | 39 | 37 | 35 | 33 | 32 | 31 | 31 | |||||
| Min | 46 | 45 | 42 | 38 | 35 | 30 | 28 | 26 | 24 | 23 | 21 | 20 | - | - | - | ||||||
