Heat treatment method for improving anti-fatigue performance of spring steel SK5 for automobile safety belt coil spring

The invention discloses a heat treatment method for improving anti-fatigue performance of spring steel for an automobile safety belt coil spring, belonging to the field of spring steel production processes. The heat treatment method disclosed by the invention comprises the following four steps: performing pretreatment, quenching, performing retreatment and tempering. The spring steel for the automobile safety belt coil spring adopts a quenching-tempering heat treatment technology, and high anti-fatigue performance and service life can be obtained, so that high-quality steel for the automobile safety belt coil spring can be produced at home without depending on import.