In front of the spring steel heat treatment should pay attention to two points: first, the rolling surface is usually made of spring steel surface, so try to avoid cracking, folding and spot scars and hairline, bubbles, sandwich and pressed into the oxide skin and so on. Second, the lower surface decarburization of spring steel in fatigue strength, should abide by strict inspection decarburized layer depth.
After the heat treatment, it should be noted: first, the naked eye or with a low magnification Magnifier spring surface, determine whether there are cracks, corrosion, pitting, and severe deformation. Second, determine the hardness and its uniformity of compliance. At the time of mass production, allowing the use of file random inspections on hardness, but attention must be filed where the mark cannot affect the precision of spring finally determine. Third, the microstructure is Tolstoy or troostite, sorbite mixed organization. Finally, after leaf spring Assembly, often working under load to spring a permanent deformation of static deflection experiment.
