High strength spring steel with excellent anti-fatigue property

Abstract

The invention belongs to the steel alloy domain and is mainly fit for the high strength spring steel with excellent ability of resisting the tire wreck and the resisting draw intension keeping above 1800MPa. The element component (weight percent) of the steel: C 0.35-0.55%, Mn 0.40-0.70%, Si 1.70-2.50%, Cr 0.70-1.10%, V 0.05-0.20%, RE 0.005-0.10%, Ca 0.005-0.10%, Ca 0.0005_0.020%, P<0.020%, S<0.015%, O<0.015%, the remaining quantity is Fe and unavoidable impurity. The steel also contains the B 0.0005_0.0030%, Ti 0.01-0.10% or the Ni 0.01-1.50%. Compared to the existing technology, the invention has many merits such as the high resisting drag intension, the excellent resisting tire ability and the low cost.

Description

technical field [0001] The invention belongs to the field of alloy steel, and is mainly suitable for high-strength spring steel with a tensile strength above 1800 MPa and excellent fatigue resistance. Background technique [0002] In the prior art, the largest users of spring steel products are railway and automobile manufacturing industries. Due to the harsh working conditions of spring components, the requirements for spring steel are very strict. With the increasing speed of railways, the increase of load capacity and the lightweight and high performance of automobiles, new requirements are put forward for improving the load-bearing stress level of springs. However, as the stress level of the spring components increases, the fatigue resistance of the springs made of existing spring steel will be significantly reduced, which cannot meet the requirements. This requires improving the fatigue resistance of spring steel while increasing its strength level. [0003] In recen...

AI Technical Summary

Problems solved by technology

Although the idea of ​​reducing the C content (0.30-0.50%) in the spring steel is adopted in the Chinese patent ZL 01104026.2, it contains more precious elements Ni, Mo

The idea of ​​reducing the C content (0.34-0.43%) in the spring steel is also adopted in the Chinese patent ZL98113532.3, but at the same time the Si content (0.80-1.40%) in the steel is low, which reduces the other properties of the spring steel except fatigue resistance. An important property - resistance to loss of elasticity

These are all limited in practical application, and more importantly, the range of improvement of spring steel fatigue resistance is limited, which affects its popularization and application.