The gear induction of low-quenching steel is quenched is the former Soviet meritorious scientist invented. As early as the 1960s, it was applied to the automotive rear bridge gear, the tractor final drive gear, etc. In the 1970s, my country also developed 55Ti, 60Ti, 70Ti and other low-quenching steels, which were used in the production of tractors and coal gears, but there were problems such as steel components control and supply. Now Russia's MA3 and KAMA3 automotive plants have a large number of low-endonal steel to produce heavy-duty drive gears.
The low-quenching steel gear induction is characterized by the gear tooth the tooth portion of the gear, when quenching is quenched, since the hardenability of the steel is particularly low, the hardness of the tooth profile is obtained, and the hardness of the teeth is also Got improved. Sketching steel is medium carbon steel, but the total content of these alloy elements of Mn, Cr, Ni, and Cu is controlled below 0.5% (mass fraction), and the tooth is hot, but due to extremely low hardenability, Under strong cold conditions, only the thin layer of the outer table is hardened, and the hardness of the tooth core is slightly improved. The crystal grain size of low-fermentable steel is from 11 to 12, and the grain size of the general steel is 7 to 8, and the grain refinement enhances the crispy fracture properties. After the gear is hot, the surface residual stress of the gear can reach 600 MPa, enhance the ability of anti-fatigue breakage.