Ordinary high manganese steel has less work hardening and insufficient wear resistance under low stress wear or small impact load. Adding Ti, V, Nb, Cr, Mo, W, B, rare earth and other elements can improve the properties of high manganese steel, so the alloyed high manganese steel bucket teeth have been developed. When Ti, V and Nb are dissolved in the matrix, they can improve the hardenability of steel. They have strong affinity with C and can form fine and strong carbides, promote the uneven nucleation of steel and prevent the growth of steel grains, so as to refine the grains and improve the strength, impact toughness and work hardening effect of steel. Moreover, tic, VC and NBC are very hard, which is conducive to improve the wear resistance of materials. The addition of Cr can improve the yield strength and work hardening properties of high manganese steel. Mo and W can refine the grains of high manganese steel and improve the yield strength, toughness and work hardening properties of high manganese steel. By adding 1% ~ 2% Mo or 1% ~ 2% w, the impact wear resistance of high manganese steel is improved by more than 20%.
In China, the service life of alloyed high manganese steel bucket teeth produced by Shougang Machinery Plant is 70% ~ 170% longer than that of ordinary high manganese steel when shoveling iron ore with Proctor hardness of 12 ~ 14. When zgmn13cr high manganese steel containing Cr is used in the integral bucket teeth of 10m3 excavator, the excavation volume can reach 536900 tons per pair. ZGMn13 vtimo steel is treated with rare earth and ferrotitanium in front of the furnace and then precipitated and strengthened. Its service life is nearly twice longer than that of ordinary high manganese steel bucket teeth.
Amsco and ESCO of the United States use the method of adding CR, Mo or Ni to produce alloyed high manganese steel bucket teeth. The composition (mass fraction) of my (CR added high manganese steel) of Amsco company is: 1.00% ~ 1.40% C, Mn content is not less than 10.0%, 2.00% Cr, 0.3% ~ 1.0% Si, s content is not more than 0.05%, P content is not more than 0.10%, yield strength is 380MPa, and yield strength is 8% ~ 10% higher than that of standard high manganese steel, However, it does not reduce the fatigue strength and has strong deformation resistance. The composition of MOH (high manganese steel with Mo): 1.00% ~ 1.40% C, Mn content not less than 10.0%, 0.3% ~ 1.0% Si, s content not more than 0.05%, P content not more than 0.10%, Mo content not disclosed, yield strength 450MPa, yield strength 15% ~ 30% higher than that of standardized high manganese steel, and good deformation resistance, However, it is not applicable to thick castings. In addition, the service life of a nickel containing high manganese steel (1.5% ~ 2.0% Ni, 12% ~ 14% Mn) used in the United States as bucket teeth is also extended.