For 65Mn spring steel, manganese can improve hardenability. Steel with diameter of 12mm can be quenched in oil. The decarburization tendency of steel surface is smaller than that of silicon steel. The comprehensive mechanical properties after heat treatment are better than that of carbon steel, but it has overheat sensitivity and temper brittleness. It can also be used for spring ring, valve spring, clutch spring, brake spring and cold drawn coil spring.
The strength, hardness, elasticity and hardenability of 65Mn steel are higher than those of No. 65 steel. It has the tendency of overheat sensitivity and temper brittleness, and water quenching has the tendency to form cracks. The machinability of annealed state is acceptable, the cold deformation plasticity is low, and the weldability is poor. Spring ring diameter up to 20 MM-7. High wear resistant parts, such as grinding machine spindle, spring clip, precision machine tool screw rod, cutter, sleeve ring on spiral roller bearing, rail, etc.