Carbon spring steel wire should have high tensile strength, elastic limit, endurance and fatigue strength, and impact and vibration resistance. To ensure the strength and endurance index, especially to avoid changing the occurrence of cracks, is the key to produce spring steel wire. The inner quality and surface quality of the wire rod directly affect the function of the wire.
Carbon spring steel wire is made of high carbon and high quality carbon structural steel or carbon tool steel wire rod, and its chemical composition, gas content and non-metallic inclusion must be strictly controlled according to the use of the spring. In order to reduce the surface defects and decarbonization layer, the billet produced wire rod should be ground on the surface and peeled when necessary.
The wire rod should be normalized or soxhlet processed, instead of spheroidal annealing for standard large ones. Soxhlet process is widely used in the heat treatment of the center, especially the products before drawing. Avoid decarbonization during heat treatment. After heat treatment, sulfuric acid or hydrochloric acid pickling is used to remove iron sheet. The coating (see smooth carrier) can be dip-lime, phosphating, borax treatment or copper plating.
The drawing process of the product drawing process has a great influence on the product function. Generally, a large total surface reduction rate of about 90% (see area reduction rate) and a small pass surface reduction rate (about less than 23%) are selected to ensure the endurance of the product. On the high strength spring steel wire, drawing should control the exit temperature of each passage of the steel wire is lower than 150℃, to avoid the steel wire due to strain aging and appear to change the crack, which is the formation of steel wire scrap the primary disadvantage.
Post time: 18-08-22