Cold Saw Blade Substrate Heat Treatment Optimization, Reduce

The substrate of cold saw blade bears cyclic mechanical load and continuous cutting heat in long-time metal cutting process. Uneven internal residual stress and improper hardness distribution after heat treatment will lead to inconsistent thermal expansion of the substrate. Under continuous heating, the blade is prone to thermal deformation, resulting in increased end runout, poor cutting section flatness, tooth chipping and shortened service life. Unreasonable quenching and tempering temperature, improper holding time and uncontrolled cooling rate are the main inducements for unstable substrate performance.

The heat treatment optimization adopts graded quenching and low-temperature tempering process. Control the heating rate to avoid excessive temperature gradient inside the steel substrate. Set reasonable quenching temperature and holding duration to obtain uniform martensite structure without coarse grain. After quenching, implement low-temperature tempering to release quenching residual stress, reduce brittleness while maintaining the required substrate hardness and rigidity. Segmented temperature control can be adopted for large-diameter cold saw blades to balance the heat treatment effect of edge and central area.

Strictly control cooling medium and cooling speed. Too fast cooling will produce huge thermal stress and cause microcracks inside the substrate; too slow cooling fails to reach the target hardness. After heat treatment, flatness correction and stress relief aging are carried out to stabilize the substrate structure. Sampling inspection is required for hardness uniformity, metallographic structure and residual stress level of finished substrates.

After heat treatment optimization, thermal cycling simulation test and cutting bench test are carried out. Continuously track the substrate deformation trend under long cutting cycle, and check the fluctuation of blade runout. The subsequent processes such as tooth machining and brazing shall also control thermal input to prevent introducing new stress to the optimized substrate.

Through the optimization of heat treatment process for cold saw blade substrate, the internal residual stress is fully released, the structural stability of the substrate under high temperature is improved, thermal deformation during continuous cutting is reduced, the cutting precision is maintained, and the comprehensive service life of cold saw blade is extended.