摘要 |
A washer-type spring, commonly called a Belleville spring, which has an improved fatigue life and residual compressive stresses resulting from the creation of a carbon gradient through the spring thickness. This improved spring is formed from a plain carbon or low alloy steel which, after blanking, cutting and forming, is heated to a temperature above the austenitizing temperature in a carbon-rich atmosphere, held at this temperature until suitably carburized, and then quenched. |