The invention discloses a process for realizing sorbitizing cold rolling of high-strength and high-fatigue spring
narrow band steel. High-
carbon steel SK5 with the thickness of 2.5mm is selected; the process comprises the process routes of unreeling and shelling,
pickling, temper rolling, reeling, first-stage cold rolling, isothermal
quenching, second-stage cold rolling, striping and packaging; process parameters are set as follows: the outlet thickness of a temper
rolling mill is set to be 2.3mm; the first-stage cold rolling thickness is 1.9mm; lead bath is adopted in isothermal
quenching, the lead bath entering temperature is 790 DEG C, the lead bath temperature is 420 DEG C, the band steel running speed is 2.0m / min,
water cooling is carried out after a structure is taken out of the lead bath, and the structure taken out of the lead bath is required to be a sorbite; and a finished product with the thickness of 0.25mm is rolled by three rolling processes in the second-stage cold rolling. A safety belt collecting
coil spring produced by using the process disclosed by the invention is subjected to durability test for 90000 times or above, so that the requirement for materials of medium-high-end cars is met.