Case hardening steels
Case hardening steels are steels designed to develop a hard, wear-resistant surface while retaining a tough and ductile core. They are used for components such as gears, shafts and other machine parts exposed to contact wear and cyclic loading.
| Grade | Material no. | C | P | S | Mn | Si | Cr |
|---|---|---|---|---|---|---|---|
| 20CrMoS2 | 1.7311 | 0,18-0,23 | 0,035 | 0,020-0,040 | 0,60-0,80 | 0,15-0,35 | 0,50-0,70 |
| 20MoCrS3 | 1.7319 | 0,17-0,23 | 0,025 | 0,020-0,040 | 0,60-0,90 | ≤0,40 | 0,40-0,70 |
| 20MoCr3 | 1.7320 | 0,17-0,23 | 0,025 | 0,035 | 0,60-0,90 | ≤0,40 | 0,40-0,70 |
| 20MoCr4 | 1.7321 | 0,17-0,23 | 0,025 | 0,035 | 0,70-1,00 | ≤0,40 | 0,30-0,60 |
| 20MoCrS4 | 1.7323 | 0,17-0,23 | 0,025 | 0,020-0,040 | 0,70-1,00 | ≤0,40 | 0,30-0,60 |
| 25MoCr4 | 1.7325 | 0,23-0,29 | 0,035 | 0,035 | 0,60-0,90 | 0,15-0,40 | 0,40-0,60 |
| 25MoCrS4 | 1.7326 | 0,23-0,29 | 0,035 | 0,020-0,035 | 0,60-0,90 | 0,15-0,40 | 0,40-0,60 |
| 22CrMoS3-5 | 1.7333 | 0,19-0,24 | 0,025 | 0,020-0,040 | 0,70-1,00 | ≤0,40 | 0,70-1,00 |
| 22CrV3 | 1.7511 | 0,20-0,24 | 0,035 | 0,035 | 0,60-0,75 | ≤0,35 | 0,65-0,80 |
| SAE 1010 | 1.9301 | 0,08-0,13 | 0,03 | 0,05 | 0,30-0,60 | — | — |
Standards covering this category
28- DIN / EN60 grades
- AISI / SAE37 grades
- UNS33 grades
- AFNOR29 grades
- PN28 grades
- GOST26 grades
- ČSN24 grades
- SRPS22 grades
- UNI21 grades
- UNE20 grades
- ISO20 grades
- BS19 grades
- JIS19 grades
- GB16 grades
- MSZ14 grades
- SS12 grades
- BDS11 grades
- STN10 grades
- STAS10 grades
- COPANT8 grades
- KS6 grades
- AS / NZS5 grades
- ÖNORM5 grades
- NBN5 grades
- SFS5 grades
- ASTM3 grades
- SNV3 grades
- HRN2 grades
Property ranges
18| Property | Unit | Min | Max | Grades |
|---|---|---|---|---|
| Rm | N/mm² | 320 | 1570 | 20 |
| Re | N/mm² | 390 | 1320 | 9 |
| A | % | 7 | 20 | 6 |
| A5 | % | 7 | 19 | 9 |
| Z | % | 40 | 55 | 7 |
| KCU | kJ/m² | 590 | 1130 | 8 |
| HB | — | 85 | 269 | 38 |
| HRB | — | 73 | 84 | 4 |
| HV | — | 135 | 260 | 4 |
| rho | g/cm³ | 7.63 | 7.85 | 60 |
| E | GPa | 129 | 216 | 4 |
| alpha | 10^-6/K | 10 | 15.6 | 4 |
| lambda | W/(m·K) | 19 | 42 | 4 |
| cp | J/(kg·K) | 495 | 706 | 3 |
| Ac1 | °C | 715 | 750 | 6 |
| Ac3 | °C | 773 | 850 | 6 |
| Ar3 | °C | 675 | 755 | 4 |
| Ar1 | °C | 625 | 665 | 4 |
Derived from 60 grades in this category with a recorded value.
Composition range
15| Property | Unit | Min | Max | Grades |
|---|---|---|---|---|
| B | % | 0.0008 | 0.005 | 2 |
| C | % | 0.07 | 0.31 | 60 |
| N | % | 0.007 | 0.012 | 4 |
| O | % | 0.002 | 0.002 | 2 |
| Al | % | 0.01 | 0.05 | 11 |
| Si | % | 0.1 | 0.5 | 59 |
| P | % | 0.02 | 0.045 | 60 |
| S | % | 0.01 | 0.05 | 60 |
| V | % | 0.1 | 0.2 | 2 |
| Cr | % | 0.1 | 2.1 | 49 |
| Mn | % | 0.3 | 1.7 | 60 |
| Ni | % | 0.1 | 4.75 | 22 |
| Cu | % | 0.15 | 0.3 | 6 |
| Mo | % | 0.05 | 0.5 | 24 |
| Pb | % | 0.15 | 0.35 | 2 |
Derived from 60 grades in this category with a recorded value.
Heat treatment
9| Operation | MinTemperature (°C) | MaxTemperature (°C) | Grades |
|---|---|---|---|
| tempering | 200 | 750 | 8 |
| quenching | 780 | 1050 | 8 |
| carburizing | — | — | 6 |
| soft_annealing | — | — | 6 |
| annealing | 950 | 950 | 6 |
| quench_and_temper | — | — | 3 |
| spheroidize_annealing | — | — | 3 |
| normalizing | 900 | 960 | 3 |
| solution_annealing | — | — | 1 |