High-strength and high-toughness automobile suspension spring steel and production method thereof

Abstract

The invention relates to the technical field of automobile suspension spring steel, in particular to high-strength and high-toughness automobile suspension spring steel and a production method thereof. The steel comprises the following chemical components in percentage by weight: 0.5%-0.6% of C, 1.2%-1.6% of Si, 0.60%-0.9% of Mn, 0.6%-0.9% of Cr, 0.01%-0.3% of V, less than or equal to 0.015% of P, less than or equal to 0.015% of S, less than or equal to 0.0015% of Ti, 0.0005%-0.0050% of total aluminum, less than or equal to 0.0025% of total oxygen, less than or equal to 0.0050% of N, less than 0.1% of inevitable impurities and the balance of iron. Through brand new low-alloy-content and low-cost chemical component design and in cooperation with appropriate converter smelting, refining, continuous casting, continuous rolling, wire rod rolling, drawing, heat treatment and other processes, the technical problems that the 2000MPa-grade automobile suspension spring steel wire is excessive in strength and insufficient in plasticity and toughness are solved. The tensile strength of the steel can reach 2000 MPa level and 2100 MPa level respectively, and the area reduction rate is larger than or equal to 45%. The spring steel not only has the excellent mechanical properties of high toughness, but also has the advantages of low cost, low decarburization, high surface quality, high purity and excellent fatigue property.

Description

technical field [0001] The invention relates to the technical field of automobile suspension spring steel, in particular to a high-strength and toughness automobile suspension spring steel and a production method thereof. Background technique [0002] 55SiCr spring steel is a Si-Cr series spring steel, mainly used to make automobile suspension springs. It is currently the most widely used steel type for making automobile suspension springs. This steel has excellent fatigue performance and anti-elasticity loss performance . [0003] At present, in the industrial production process, the tensile strength of the oil-quenched and tempered steel wire made of the steel wire rod after drawing and heat treatment can reach 1800MPa (1750MPa~1850MPa), 1900MPa (1850MPa) depending on the production process. ~1950MPa) and 2000MPa grade (1950MPa~2050MPa). [0004] However, in the actual production process of 2000MPa oil-quenched and tempered suspension spring steel wire, if there is a cer...

AI Technical Summary

Problems solved by technology

However, the above method will sacrifice the strength, which will eventually lead to a decrease in the strength of the steel wire, so that it cannot meet the technical standard requirements of 2000MPa steel wire

Images