Alloy engineering steel and high pressurre boiler steel 25CrMo4, 1.7218, AISI 4130 with increased strength for construction and operation at elevated temperatures.
| Standards | Steel Grades | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Composition % | ||||||||||||||
| C: | Mn: | Si: | P: | S: | Cr: | Mo: | Ni: | V: | Ti: | Cu: | N: | W: | Al: | |
| PN | 25HM | |||||||||||||
| 0.22 - 0.29 | 0.40 - 0.70 | 0.17 - 0.37 | <0.035 | <0.035 | 0.8 - 1.1 | 0.15 - 0.25 | <0.3 | - | - | - | - | - | - | |
| PN | 20HM | |||||||||||||
| 0.19 - 0.26 | 0.50 - 0.80 | 0.15 - 0.35 | <0.035 | <0.035 | 0.9 - 1.2 | 0.4 - 0.5 | <0.6 | - | - | - | - | - | <0.02 | |
| GOST | 20ChM - 20KhM - 20ХМ | |||||||||||||
| 0.15 - 0.25 | 0.40 - 0.70 | 0.17 - 0.37 | <0.035 | <0.035 | 0.8 - 1.1 | 0.15 - 0.25 | <0.3 | <0.05 | <0.03 | <0.3 | <0.008 | <0.2 | - | |
| EN | 25CrMo4 - 1.7218 - 25 CrMo 4 - 7218 | |||||||||||||
| 0.22 - 0.29 | 0.60 - 0.90 | <0.4 | <0.025 | <0.035 | 0.9 - 1.2 | 0.15 - 0.30 | - | - | - | - | - | - | - | |
| DIN SEW | 24CrMo5 - 24 CrMo 5 - 1.7258 - 7258 - DIN 17240 / SEW 550 | |||||||||||||
| 0.20 - 0.28 | 0.50 - 0.80 | <0.4 | <0.035 | <0.035 | 0.9 - 1.2 | 0.20 - 0.35 | <0.6 | - | - | - | - | - | - | |
| ISO | 20CrMo4 - 20 CrMo 4 - 1.3567 - 3567 | |||||||||||||
| 0.17 - 0.23 | 0.60 - 0.90 | <0.4 | <0.025 | <0.030 | 0.9 - 1.2 | 0.15 - 0.25 | - | - | - | <0.3 | - | - | <0.05 | |
| AISI | AISI 4130 / SAE 4130 | |||||||||||||
| 0.28 - 0.33 | 0.40 - 0.60 | 0.20 - 0.35 | <0.035 | <0.040 | 0.8 - 1.1 | 0.15 - 0.25 | - | - | - | - | - | - | - | |
| GB/T | 30CrMo | |||||||||||||
| 0.26 - 0.34 | 0.40 - 0.70 | 0.17 - 0.37 | <0.035 | <0.035 | 0.8 - 1.1 | 0.15 - 0.25 | <0.3 | - | - | <0.3 | - | - | - | |
25CrMo4 - specification and applications
25HM steel, which is a Polish equivalent of 25CrMo4, is alternately classified as structural steel for heat improvement and as a boiler steel designed to work at elevated temperatures. It exhibits very good strength properties, high ductility, weldability and good hardenability. Compared to the 35HM and 34CrMo4 grades, after heat treatment it has slightly worse strengths, but it makes up for the lower properties with much better ductility.
25HM achieves best durability values at dimensions up to 65mm after hardening in water, while after hardening in oil at dimensions and thicknesses up to 40mm. It is most often found in a heat-treated or softened state - less commonly in the normalized state.
For use in high temperature applications - the power industry - this steel is used in the production of parts working at 450 - 530 ℃, which exhibit creep resistance: flanges and welds for pipes, covers, nuts, heavy-duty screws, turbine rotors, turbine blades, toothed shafts, steam pipes, control parts, and levers.
Dla zastosowań pracy w podwyższonych temperaturach - przemysł energetyczny - opisywana stal znajduje zastosowanie w produkcji części pracujących w temperaturach 450 - 530℃, które wykazują odporność na pełzanie, czyli: kołnierzy i wieńcy spawanych do rur, pokryw, nakrętek, obciążonych śrub, łopatek i wirników turbin, tarczy turbin, wałów uzębionych, przewodów parowych, części sterujących, drągów oraz dźwigni.
General mechanical properties of 25CrMo4 / 1.7218 / AISI 4130 steel
- Tensile strength, Rm > 740 MPa
- Yield point, Re > 590 MPa
- Contraction Z > 55%
- Elongation A > 15%
- Density = ~ 7,85 g/cm3
- Notch toughness > 80 J
- Hardness in softened annealed state < 217 HB
Mechanical properties of bars acc. to EN 10269 (pressure/temperature application) in +QT condition
- Sizes <100mm
- Rm: 600-750 N/mm2
- Rp0,2: >400 N/mm2
- A: >18%
- Z: >60%
- KV 20C: >60J
- Sizes 100-150mm
- Rm: 600-750 N/mm2
- Rp0,2: >420 N/mm2
- A: >18%
- Z: >60%
- KV 20C: >60J
Mechanical properties of bars EN 10083-3 (engineering application)
- Sizes <16mm in +QT condition
- Rm: 900 - 1100 N/mm2
- Rp0,2: >700 N/mm
- A: >12%
- Z: >50%
- Sizes 16-40mm in +QT condition
- Rm: 800-950 N/mm2
- Rp0,2: >600 N/mm2
- A: >14%
- Z: >55%
- KV 20C: >50J
- Sizes 40-100mm in +QT condition
- Rm: 650-800 N/mm2
- Rp0,2: >400 N/mm2
- A: >16%
- Z: >60%
- KV 20C: >45J
- Sizes 100-150mm in +QT condition
- Rm: 650-800 N/mm2
- Rp0,2: >400 N/mm2
- A: >16%
- Z: >60%
- KV 20C: >45J
- Hardness HBW in +A condition: <212
- Hardness HBW in +S condition: <255
Mechanical properties of coldrolled strips acc. to EN 10132-3
- Condition +A+LC
- Rm: <580 N/mm2
- Rp0,2: <440 N/mm
- A: >19%
- Hardness HV: <175
- Hardness HRB: <87
- Condition +QT
- Rm: 990 - 1400 N/mm2
- Hardness HRC: 31,5 - 44,0
- Hardness HV: 305-435
Seamless construction tubes acc. to EN 10305, DIN 2391 and high pressure acc. to EN 10216-2
- Colddrawn hardened +C / BK
- Rm: 720 N/mm2
- A: >4%
- Colddrawn Semi-hardened +LC / BKW
- Rm: >670 N/mm2
- A: >6%
- Colddrawn stress relieved +C+SR / BK+S
- Rm: 650-900 N/mm2
- Rp0,2: >600 N/mm2
- A: >10%
- Colddrawn annealed +A / GBK
- Rm: 500-620 N/mm2
- Rp0,2: >300 N/mm2
- A: >24%
- HB: <215
- HRB: <96
- Colddrawn normalized +N / NBK
- Rm: 620-800 N/mm2
- Rp0,2: >390 N/mm2
- A: >18%
- Hotrolled for high pressures +QT acc. to EN 10216-2
- Rm: 540-690 N/mm2
- Rp0,2: >345 N/mm2
- A: >18%
- KV 20C: >40J
Open Die forgings acc. to EN 10250-3 in +QT condition - Longitudial results
- Sizes <70mm
- Rm: >700 N/mm2
- Rp0,2: >450 N/mm2
- A: >15%
- KV 20C: >50J
- Sizes 70-160mm
- Rm: >650 N/mm2
- Rp0,2: >400 N/mm2
- A: >17%
- KV 20C: >45J
- Sizes >160mm
- Rm: >600 N/mm2
- Rp0,2: >380 N/mm2
- A: >18%
- KV 20C: >38J
Heat treatment and its process
- Soft annealing a t680 - 720℃ with slow cooling in the furnace
- Normalizing annealing at 860 - 900 °C with slow cooling in air
- Hardening in oil or water at 840 - 880℃
- Tempering at 540 - 680 °C with cooling in air
- Eelief annealing at 650 - 700℃
Creep limit and creep resistance of 25HM steel
| Properties (MPa) | Temperatures | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 420℃ | 430℃ | 440℃ | 450℃ | 460℃ | 470℃ | 480℃ | 490℃ | 500℃ | 510℃ | 520℃ | 530℃ | 540℃ | 550℃ | |
| Rz/10000 | 387 | 364 | 338 | 311 | 283 | 255 | 227 | 200 | 177 | 153 | 133 | 114 | 95 | 78 |
| Rz/100000 | 308 | 280 | 253 | 226 | 200 | 178 | 157 | 136 | 118 | 100 | 82 | 66 | 51 | 36 |
| R1/10000 | 274 | 258 | 242 | 227 | 210 | 195 | 179 | 163 | 147 | 130 | 115 | 98 | 81 | 64 |
| R1/100000 | 221 | 203 | 186 | 171 | 155 | 141 | 127 | 112 | 98 | 83 | 69 | 54 | 39 | 25 |
| R0,2/10000 | 204 | 188 | 175 | 162 | 149 | 135 | 124 | 112 | 100 | 88 | 77 | 66 | 55 | 46 |
| R0,2/100000 | 165 | 151 | 138 | 126 | 113 | 100 | 87 | 75 | 64 | 53 | 42 | 32 | 24 | 18 |
In the above mentioned grades the company provides:
- Hot-rolled, peeled, bright and drawn bars 25CrMo4, 1.7218
- Forged bars and Open Die forgings 25CrMo4, 1.7218
- Colddrawn tubes AISI 4130, 25CrMo4, 1.7218
- Coldrolled strips 25CrMo4, 1.7218
- Sheets and plates AISI 4130, 25CrMo4, 1.7218
In the above mentioned grades the company provides:
25CrMo4, 25 CrMo 4, 24CrMo5, 24 CrMo 5, 1.7218, 7218, 1.7258, 7258, 20ChM, 20KhM, 20CrMo4, 20 CrMo 4, 1.3567, 3567, Blachy AISI 4130, Blachy SAE 4130, Rury AISI 4130, Rury SAE 4130, 30CrMo, G26CrMo4, 1.7221, 4130H, SF-5, 20CrMo, CSN 15130, 30CrMo4, 30 CrMo 4, 1.7216, 25CD4, 25 CD 4, 23CrMo5, 23 CrMo 5, MCrMo, IASC7218, 20HM, 25HMA, L25HM, 30HM, 26MoCr11, 26 MoCr 11, T 30CrMo3, F-222, G41300, H41300, G41310, H41304, C4730, 20ХМ, 30ХМ.