Spring steel production process

- Jan 12, 2018-

General spring steel can be used electric furnace, open hearth or oxygen converter production; better quality or special quality spring steel with electroslag furnace or vacuum furnace refining. Spring steel carbon, manganese, silicon and other major elements of the provisions of a narrow range of content, smelting must be strictly controlled chemical composition. When the silicon content is high, bubbles and other defects are easy to form. When the ingot is rough, the white spots tend to be generated when it is not cooled properly. Therefore, the smelting raw materials must be dry, try to remove gases and inclusions, but also to avoid overheating molten steel.

Spring steel in the rolling process must pay special attention to decarburization and surface quality. Steel surface decarburization, it will significantly reduce the fatigue limit of steel. For high silicon spring steel such as 70Si3MnA, care should be taken to avoid graphitization. Therefore, the hot rolling stop rolling temperature should not be too low (≥ 850 ℃), to avoid graphitization easier to form the temperature range (650 ~ 800 ℃) residence time is too long.

After the spring made of shot peening can make the spring surface residual compressive stress to offset part of the surface of the work stress and inhibit the formation of surface cracks, which can significantly increase the fatigue limit of the spring.