The alloying of high-manganese steel is mainly achieved by adding Cr, Mo, V, Ti, rare earth and other elements to the high-manganese steel of traditional composition, and the use of Cr is particularly wide. Relevant text
The alloying of high-manganese steel is mainly achieved by adding Cr, Mo, V, Ti, rare earth and other elements to the high-manganese steel of traditional composition, and the use of Cr is particularly wide. Relevant literatures believe that: in the process of high-manganese steel work hardening, dynamic strain aging will occur, that is, the formation of C-Mn atom pairs, the altar escapes from the sputum, the stagnation of the industry, the recruitment of the elements, the addition of elements, and the expansion of high manganese. Cluster effect of C-Mn ordered atom pairs in steel. In this paper, the changes of microstructure, structure, electrical resistance and wear resistance of alloy high manganese steel and ordinary high manganese steel with different tempering temperatures were studied. The results showed that the alloy high manganese steel was under the condition of relatively low carbon content. Its wear resistance is superior to ordinary high manganese steel. Moreover, the different microstructures of the alloy high manganese steel at different tempering temperatures show different wear resistance.
After the high-manganese steel was treated by water toughness, the aging temperature gradually increased to 250 °C, the wear of the alloy high-manganese steel decreased, and the wear resistance increased, which was the maximum at 250 °C. When the temperature is raised from 250 °C to 350 °C, the wear amount is slightly increased, and the wear resistance is decreased, but it is still better than the wear resistance of the alloy high manganese steel after the conventional water toughening treatment. When the temperature continues to rise to 500 ° C, the wear amount continues to increase, the wear resistance decreases, and the wear resistance is lower than that in the water tough state, which further proves the existence of ordered microdomains in the alloy high manganese steel.
For ordinary high manganese steel, as the temperature increases, the carbon atoms in the austenite matrix also migrate and form a C-Mn atom pair with Mn, but the binding between manganese and carbon atoms is relatively weak. The size of the short-range ordered micro-region is relatively small, and the lattice distortion after tempering at 250 °C has a certain degree of recovery, so the wear resistance after tempering at 250 °C is better than that of the water-resistant state. Sex has hardly improved. As the solid solution strengthening effect is weakened, the wear resistance is slightly decreased. When the tempering temperature continues to rise from 250 ° C to 350 ° C, the activity of carbon atoms in the alloy high manganese steel continues to increase with the increase of temperature, and there is no carbide precipitation after the temperature tempering treatment, but at this time, the austenite The degree of lattice distortion of the body is further reduced, and the solid solution strengthening effect is weakened. However, since the carbide has not precipitated, a large number of microdomains still exist, and the wear resistance is lower than that at 250 °C, but it is still lower than the water tough state. High wear resistance. For ordinary high-manganese steel, when the temperature rises to 400 °C, the carbides in some carbon-rich micro-domains begin to precipitate from the diffraction spectrum. At this time, the newly precipitated carbides have not grown, and the dispersion strengthening effect is compared. ideal. Other microdomains are still in the substructure state before carbide precipitation, because the microdomains of these substructure states are carbon-rich regions, so C-Mn ordered atom pairs are abundant. These diffusely uniformly distributed microdomains and the pinning effect of dispersively distributed carbides on dislocations compensate for the weakening of solid solution strengthening to a certain extent, so the macroscopic mechanical properties show that the wear resistance is not significantly reduced. When the temperature continues to rise to 500 ° C, as can be seen from Figure 4, the alloy high manganese steel begins to precipitate carbides, at this time the basic lattice constant of austenite has basically become normal, and due to the precipitation of alloy carbide, the matrix contains The carbon content decreased significantly, which greatly affected the formation of ordered micro-regions, thus affecting the effect of work hardening, so the macroscopic wear resistance showed a downward trend.
It can be seen that the micro-cluster of C-Mn ordered atom pairs has an important influence on the wear resistance of high manganese steel. The water-toughened alloy high-manganese steel, after tempering at 250 °C, exhibits wear resistance higher than that of ordinary high manganese with higher carbon content due to the "hinge effect" of Cr on C-Mn atom pair. steel. After the tempering temperature of the alloy high manganese steel is increased to 500 °C, the strengthening of the ordered clusters is weakened by the influence of the precipitation of carbides, and the wear resistance of the alloys is significantly reduced.