X120Mn12 are high-wear abrasive austenitic Non-magnetic steel(Non Magnetizable Steels), characterized by high carbon content - on average 1.00-1.20%, and high Manganese content - approx. 12%. The ranges of concentration of carbon and manganese depend on the equivalents of the grades of different origin. The abrasion-resistant steel grades may differ from the standard, which are also included in the presented table.Surface hardening during grinding and crumbling, good ductility, impact resistance and the ability to withstand dynamic loads are the basic criterion for the selection and use of steel. The second essential property is that high-manganese steel, after appropriate heat treatment, is a non-magnetic steel. The third and probably the last is the high hardness of the material in the supersaturated state - about 500 HBW. X120Mn12 abrasion resistant steel strengthens during operation, it is used for elements of equipment and machines that are exposed to abrasion at dynamic and high surface pressures. Unfortunately, it is characterized by very difficult machinability and has low resistance to variable loads.Even the smallest small cracks lead to the formation of fatigue and to the destruction of structural parts during the operation of machinery and equipment.
| Grade | Chemical Composition WT % | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| C | Mn | Si | P | S | Cr | Mo | Ni | Cu | |
| X120Mn12, 1.3401 | 1.10 - 1.30 | 12.0 - 13.0 | 0.3 - 0.5 | Max 0.1 | Max 0.04 | Max 1.5 | - | Max 1.0 | - |
| X110Mn14, 1.3402 | 1.00 - 1.25 | 13.5 - 14.5 | 0.35 - 0.70 | Max 0.08 | Max 0.02 | - | - | - | - |
| Z120M12, Z 120 M 12, GD 233 | 1.05 - 1.35 | 11.0 - 14.0 | 0.2 - 0.6 | Max 0.045 | Max 0.035 | - | - | - | - |
| BW 10, BW10 | 1.00 - 1.35 | Min 11.0 | Max 1.0 | Max 0.05 | Max 0.05 | - | - | - | - |
| GX100Mn13, 1.3406 | 0.90 - 1.05 | 11.0 - 14.0 | 0.3 - 0.9 | Max 0.06 | Max 0.045 | - | - | - | - |
| GX120Mn13, 1.3802 | 1.05 - 1.35 | 11.0 - 14.0 | 0.3 - 0.9 | Max 0.06 | Max 0.045 | - | - | - | - |
| ASTM A128 | 1.05 - 1.35 | Min 11.00 | Max 1.00 | Max 0.07 | - | - | - | - | - |
| Mechanical and physical properties of X120Mn12(1.3802) | |
|---|---|
| Tensile strength, Rm | 80 - 110 kG/mm2 |
| The yield point Re | 35 - 45 kG/mm2 |
| Elongation A5 | ≥ 40% |
| Contraction Z | 40 - 55% |
| Hardness HB | 190 - 250 kG/mm2 |
| Density, ρ | 7,71 kg/dm3 |
Temperature of 950-1000 ℃ and cooled in water, austenitic material structure.
cool 950 ℃ to room temperature, a mixture of ferrite and manganese cementite appears in the structure.When cooling steel in water from the pre-heating temperature of approx.
500 ℃, carbides (Fe, Mn) 3C are formed from austenite, with a perliteic transformation leading to a martensitic structure. This steel structure is much more workable compared to the supersaturated state.In a cast, improperly tempered or supersaturated state, or badly welded, the steel shows increased brittleness and much weaker technological and strength properties, which is associated with a decrease in abrasion resistance.These changes are caused by the separation of carbides along grain boundaries and the breakdown of austenite into structural components (perlite + martensite). In order to restore the previous similar properties to the steel, it should be heated to the supersaturation temperature, and quickly cooled in water (with smaller details in oil), which will return the previous ductility and abrasion resistance to the material.
Steel grade
Special steel