Research On Microscopic Structure And Wear-resisting Property Of Micro-alloying High Manganese Steel With Nitrogen

Micro-alloying high manganese steel with nitrogen is a new wear resistant material, which is studied in this thesis. It is obtained by adding nitrogen element to general high manganese steel Mnl3.In order to remedy the applied insufficiency of general high manganese steel such as without enough abrasion resistance as a result of inadequate deformation hardens at low stress or low impact, easily happen low temperature brittleness rupture at the condition of chilliness(-20～-40℃).This thesis has selected three nitrogen content of high manganese steel with trace nitrogen. There are0.043%,0.066%.The sample were carried out water toughening at different temperature (1050℃,1100℃) and then were carried out abrasive wear experiment under the low impact.The result shows that the wear-resisting property is improved of high manganese steel casting with trace nitrogen. The wear-resisting property increased by twenty-five percent of micro-alloying high manganese steel, compared with common high manganese steel castings. The crystal particle is small in the casting organize of high manganese steel with nitrogen, this shows that nitrogen is added to the high manganese steel, can play the role of refining the crystalline structure. The as-cast organization of micro-alloying high manganese steel adding boron element has small dot of boron phase in the austenitic grain boundary, and have oversize crystal particle. When the water toughening temperature phase at the same time, the higher nitrogen content, the better refining grain size. The effect of1050℃water toughening temperature refined grain is better at equal nitrogen content. There will be slip band in the microstructure of high manganese steel after work hardening. Under low impact abrasive wear and after water toughening at equal temperature, the wear resistance of high manganese steel with nitrogen gradually decrease, at the same nitrogen content the wear resistance is better on the1100℃water toughening temperature. The wear resistance of high manganese steel gradually enhance with the increase of nitrogen content at the same water toughening temperature after work hardening, at the same nitrogen content the wear resistance is better on the1100℃water toughening temperature.Study indicated that the high manganese steel with nitrogen0.043%has the better wear-resisting property after1100℃water toughening.