Heat treatment process of thermoforming spring

The invention relates to a heat treatment process of a thermoforming spring, which is characterized in that according to the heat treatment process disclosed by the invention, thermoforming treatment is adopted aiming to a spring with the wire diameter smaller than 15mm, and heat treatment is needed after formation; and the heat treatment process comprises the following steps of: annealing and normalizing treatment: spheroidizing annealing and softening annealing treatment, wherein the hardness is no larger than 225HBS; quenching and tempering treatment; and quenching medium selection: an alloy steel adopts an oil quenching medium, and the alloy steel with the sectional area larger than 100 square millimeters is treated by quenching by using water. According to the heat treatment process disclosed by the invention, during tempering treatment, a tempering furnace with a fan is selected to improve the uniformity of tempering, wherein the tempering temperature is 450-550 DEG C; and a rapid cooling mode of water cooling or oil cooling is adopted after tempering. The heat treatment process has the advantages of simpleness in operation, good heat treatment effect of the spring, high spring yield, good performance stability of a finished spring and long service life of the spring.