| 摘要 |
The invention relates to a production process for low-carbide, fine-grained high-carbon manganese steel castings, to the product of the process and to its use. High-carbon manganese steel (Hadfield steel) is an important wearing material, such as is used for hammer bits or grinding bits and linings in mills, dressing machinery and the like. In these cases, it is important to avoid embrittlement of the castings due to carbide precipitation in the microstructure. For this reason, the alloying with carbon and other carbide formers in order to improve the wearing properties has hitherto been limited. The production is effected by casting an "overalloyed" manganese steel melt into moulds, removal of the solidified castings from the mould before the carbide precipitation temperature is reached, and quenching the castings in water. During the subsequent solution-annealing, an even higher carbon content or carbide former content relative to the manganese is permissible, without harmful carbide precipitations remaining at the grain boundaries. The processes during cooling are evident from the phase diagram in Figure 1. <IMAGE> |
