The results show that the quenching medium of water-solubility has effectively solved the difficult problems:such as non-hardening of oil quenching and fissility of water quenching;accordingly,the soft points and quenching fissility have been avoided.

Through testing the ageing performance of TYL water-soluble quenching medium, we know that the medium has a strong anti-ageing capacity, stable chemical property,small composition change, stable cooling property, and low cost.

using the theory of four-stage differentiation of heat removal,the following analyses can be made:during the course of quenching in liquid quenchants,borrowing a demarcation line is a common phenomenon.