Spring steel with performance of low decarburization, high strength and high ductility

Abstract

The invention discloses spring steel with the performance of low decarburization, high strength and high ductility, and belongs to the field of spring steel used for hot press machining. The spring steel comprises the chemical components of, by weight, 0.42-0.52% of C, 0.70-1.10% of Si, 0.50-1.10% of Mn, 0.50-1.1% of Cr, 0.01-0.05% of V, 0.005-0.009% of Nb, no greater than 0.025% of P, no greater than 0.025% of S, 5-25 ppm of [O] and the balance Fe and inevitable impurities. Since a spring material has the technicalperformance of low decarburization, high strength and high ductility and is low in alloy content, the spring steelisan excellent material for manufacturing medium and heavy duty truck large-wire-diameter suspension spiral springs, can also be used for car suspension spiral springs, car torsion rod springs and stabilizer bars, and is also an excellent raw material for high-strength spring steel wires and oil tempering spring steel wires. The spring steel is wide in application and suitable for application and popularization in the industry.

Description

technical field [0001] The invention belongs to spring steel for thermal pressure processing, and in particular relates to a high-performance spring material and a preparation method. Background technique [0002] The lightweight of medium- and heavy-duty vehicles is an important trend in the development of automobiles, and a large number of light-weight few-leaf springs are bound to be used in lightweight design. Therefore, high strength, high plasticity, low decarburization and low cost are required for spring materials to meet the high performance and high feasibility requirements of lightweight and less leaf springs. [0003] Existing spring materials are difficult to meet the comprehensive requirements of low decarburization, high strength, high plasticity, low alloy and low cost, and can only be satisfied in one aspect as far as possible. For example, 51CrV4 spring steel can meet the requirements of low decarburization, but it does not meet the requirements of high st...

AI Technical Summary

Problems solved by technology

[0003] Existing spring materials are difficult to meet the comprehensive requirements of low decarburization, high strength, high plasticity, low alloy and low cost, and can only be satisfied in one aspect as far as possible

For example, 51CrV4 spring steel can meet the requirements of low decarburization, but it does not meet the requirements of high strength and high plasticity

54SiCr6 has high strength and high plasticity quality, but severe decarburization

[0004] Si is an important alloying element to improve the strength of spring materials, and it is rich in resources and low in use cost, but it will increase the decarburization tendency of steel and lead to the formation of a fully decarburized layer. This beneficial effect of increasing strength is related to the formation of a fully decarburized layer hazards exist at the same time

So far, the problem of fully decarburized layer of Si-containing high-strength spring steel is difficult to solve properly

South Korea’s Pohang spring steel (Chinese patent 94191328.7 disclosed) reduces the depth of the fully decarburized layer (ferrite layer) by adding Ni, “the formation of the depth of the decarburized layer is largely suppressed”, but this addition is rare and expensive The method of alloying elements to solve the problem of full decarburization layer will inevitably lead to a substantial increase in the cost of materials, so it is difficult to accept

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