Henan Friend Metal Products Co.,Ltd

Henan Friend Metal Products Co.,Ltd

GB / T4358-1995<>

The wire supplied according to this standard is primarily intended for use in the production of dynamic springs operating under various stress conditions. According to the spring working stress, the steel wire is divided into three groups: E group is suitable for medium stress dynamic spring, group F is suitable for high stress dynamic spring, G group is suitable for high fatigue life dynamic spring. Product wire check the tensile strength, change, coiling, bending and decarbonization five functional guidelines, the common standard mechanical function as shown in Table 5. Key words Carbon spring steel wire for important use GB / T4358-1995


① Φ ≤ 4.0mm steel wire is equal to the diameter of the mandrel rod, Φ ≥ 4.0mm steel wire in the 2 × diameter wire rod coiled 5 laps, no cracks or broken.

② Φ ≤ 1.0mm steel wire bending test, the sample along the R arc to the direction of bending 900, bending without cracks or broken, Φ ≤ 4.0mm, R = 5mm; Φ> 4.0mm, R = 10mm.

③ G group of steel decarburization layer ≤ 1.0d%.

Since the wire supplied according to this standard is used for the production of dynamic springs in medium and high stress conditions, it is necessary to take into account the fatigue limit and the fatigue life of the spring in addition to the high elasticity limit and the excellent resistance policy The To this end, the purity of the steel, non-metallic mixing content and gas content, ferrite content and surface decarburization degree have a higher need. It is necessary to use the electric wire to improve the chemical composition of the wire rod. P≤0.025%, S≤0.020%, Cr≤0.10%, Ni≤0.15% (0.12%), , Cu ≤ 0.20%. In the practice of production for the fatigue of the number of fatigue generally control the Mn in the high limit, E group selected 70 or 70Mn (72B), F group selected T8MnA or T9RtA, G group selected 65Mn (Mn can be adjusted to 0.9-1.2%) or 67B. The purpose of reducing the content of P, S in the steel, the forward Mn content and the choice of the essence of the furnace is to reduce the nonmetallic content of the steel, improve the shape of the mixture and reduce the gas content, the forward fatigue limit and the fatigue life. If the wire microstructure is rich in free ferrite, will be more rugged to reduce the number of fatigue life, according to the standard supply of steel wire, before the need for lead quenching.

G group of wire used in the production of severe vibration in the work of the valve spring, the fatigue life of the need for high, so the choice of very good resistance 65Mn wire rod, although the tensile strength is reduced, but the number of fatigue life is more assured. The surface of the steel wire decarburization, constitute a ferrite structure seriously affect the fatigue function, the standard group G wire to increase the decarburization layer inspection, the rules of the total decarburization depth of not more than 1.0% d, but the larger standard wire (Φ> 4.0mm) The decarburization layer brought by the hot-rolled wire rod is difficult to completely eliminate, the standard to make up for the rules: "the need to meet the demand side, the supply of decarburized layer is not super diameter 1.5% d of the wire."

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