What is U71Mn?
U71Mn is a specific grade of high-manganese, high-carbon steel used primarily for heavy-duty crane rails and railway tracks, known for its high strength, hardness, and wear resistance, indicated by 'U' (rail), '71' (around 0.71% Carbon), and 'Mn' (Manganese). It offers excellent performance under heavy loads and impacts, making it ideal for ports, factories, and large industrial applications, with properties superior to ordinary rail steel.
| Steel Grade | C(%) | Si | Mn | Cr | V | P | S | Tensile Strength (Rm/MPa) |
| U71Mn | 0.65~0.76 | 0.15~0.58 | 0.70~1.40 | – | – | ≤0.035 | ≤0.030 | ≥880 |
- Chemical Composition: Contains significant Manganese (Mn) and Carbon (C) (around 0.65-0.77%), with Silicon (Si) also present, improving strength and wear.
- High Strength & Hardness: Delivers high tensile strength (≥880 MPa) and hardness, resisting deformation from heavy crane wheels.
- Wear Resistance: The manganese content enhances its ability to withstand abrasion and repeated stress.
- Application: Commonly used in QU series crane rails (like QU80, QU100) for gantry cranes, overhead cranes, and other heavy industrial setups.
| Classification | Height(mm) | Head (mm) | Bottom (mm) | Thick(mm) | Weight (kg/m) | |
| Light Rail | 8 KG/M | 65 | 25 | 54 | 7 | 8.42 |
| 9 KG/M | 63.5 | 32.1 | 63.5 | 5.9 | 8.94 | |
| 12 KG/M | 69.85 | 38.1 | 69.85 | 7.54 | 12.2 | |
| 15 KG/M | 79.37 | 42.86 | 79.37 | 8.33 | 15.2 | |
| 18 KG/M | 80 | 40 | 80 | 10 | 18.06 | |
| 22 KG/M | 93.66 | 50.8 | 93.66 | 10.72 | 22.3 | |
| 24 KG/M | 107 | 51 | 90 | 10.9 | 24.46 | |
| 30 KG/M | 107.95 | 60.33 | 107.95 | 12.3 | 30.1 | |
| Heavy Rail | 38 KG/M | 134 | 68 | 114 | 13 | 38.733 |
| 43 KG/M | 140 | 70 | 114 | 14.5 | 44.653 | |
| 45 KG/M | 145 | 67 | 126 | 14.5 | 45.546 | |
| 50 KG/M | 152 | 70 | 132 | 15.5 | 51.514 | |
| 60 KG/M | 176 | 73 | 150 | 16.5 | 60.64 | |
| Crane Rail | QU 70 | 120 | 70 | 120 | 28 | 52.8 |
| QU 80 | 130 | 80 | 130 | 32 | 63.69 | |
| QU 100 | 150 | 100 | 150 | 38 | 88.96 | |
| QU 120 | 170 | 120 | 170 | 44 | 118.1 | |
Why use U71Mn to manufacture Steel Rail?
U71Mn steel is used for rails because its high carbon and manganese content provides exceptional strength, hardness, and wear resistance, crucial for withstanding heavy loads, impacts, and friction from trains, especially in high-speed, heavy-haul, and industrial applications, extending track life and improving safety.
Key Advantages of U71Mn Steel for Rails
- High Strength & Toughness: The manganese (Mn) content significantly enhances the steel's strength and ability to absorb impact, making it ideal for high-stress rail environments.
- Superior Wear Resistance: Manganese steel is known for work hardening; the surface becomes extremely hard and resistant to abrasion from repeated wheel contact.
- Durability: Its robust properties reduce deformation and extend the service life of tracks, lowering maintenance costs.
- Application Versatility: It's used in demanding scenarios like heavy freight lines, ports (for crane rails), high-speed railways (over 200 km/h), and industrial transport.
As a professional rail fastener supplier, GNEE RAIL can provide different standard steel rail such as American, BS, UIC, DIN, JIS, Australian and South Africa which used in railway lines, cranes and coal mining.
| Standard | Sepc. | Material Typical Grade |
| UIC860 | UIC54 | 700,900A,900B |
| UIC60 | ||
| EN13674.1 | 5.00E+02 | R200,R350HT,R260Mn,R35LHT,R320Cr,R370CrHT |
| 5.40E+02 | ||
| 6.00E+02 | ||
| 6.00E+03 | ||
| BS-11-1985 | BS80A | 700,900A,900B |
| BS90A | ||
| BS100A | ||
| AREMA | 115RE | SS,HH,LA,IH |
| 136RE | ||
| ASCE60 | U71Mn | |
| ASCE85 | U71Mn | |
| GB 2585-2007 | 50kg/m | U71Mn |
| 60kg/m | U75V | |
| 75kg/m | ||
| TB/T2344-2012 | 50kg/m | U71Mn,U75V,U77MnCr |
| 60kg/m | U78CrV | |
| 75kg/m | ||
| GB 11264-1989 | 8kg/m | Q235 |
| 12kg/m | Q235 | |
| 15kg/m | 55Q, Q235 | |
| 18kg/m | 55Q, Q235 | |
| 22kg/m | 55Q, Q235 | |
| 24kg/m | 55Q, Q235 | |
| 30kg/m | 55Q, Q235 | |
| 38kg/m | 50Mn, U71Mn | |
| 43kg/m | 50Mn, U71Mn |
