Steel with a manganese content of about 11% to 18% is called high manganese steel. The chemical composition of commonly used cast high-manganese steel ZMn13 is: Mn content 11%-14%, c content 1.0%-1.4%, Si content 0.3%-1.0%, P content <0.03%, S content <0.05%.
High manganese steel is a kind of wear-resistant steel. The high manganese steel treated by water toughness can obtain higher plasticity and impact toughness. The so-called water toughening treatment is to heat the steel to 1000℃～1100℃ for a period of time, so that all the carbides in the steel are dissolved into the austenite, and then rapidly cooled, so that the carbides cannot be precipitated from the austenite. Maintain a single uniform austenite structure. The high manganese steel that has been water toughened is called high manganese austenitic steel. Its mechanical properties are: σb=980 MPa, σs=392 MPa, HB210, δ=80%, αk=2.94 MJ/m2.
High manganese steel has high wear resistance. Although its hardness is only HB210, its yield point σs is low, only 40% of σb, so it has high plasticity and toughness. When high manganese steel is subjected to external pressure and impact load, it will produce large plastic deformation or severe work hardening. The steel is strongly strengthened, and the hardness is significantly improved, reaching HB450-550, so it has high wear resistance .
High manganese steel can be divided into high carbon high manganese wear-resistant steel, medium carbon high manganese non-magnetic steel, low carbon high manganese stainless steel and high manganese heat resistant steel. The grades and properties of several high manganese steels are shown in Table 5-1.