Novel high-strength LPD50 spring steel

Abstract

The invention discloses novel high-strength LPD50 spring steel, and belongs to the field of high-strength spring steel for thermal pressure machining purposes and manufacturing technologies. The novel high-strength LPD50 spring steel is characterized in that the novel high-strength LPD50 spring steel comprises the following components, by mass percent, 0.47-0.53% of C, 0.15-0.35% of Si, 0.75-1.10% of Mn, 0.90-1.20% of Cr, 0.05-0.10% of V, 0.02-0.10% of Nb, 0.15-0.25% of Mo, less than or equal to 0.25% of Cu, less than or equal to 0.25% of Ni, less than or equal to 0.02% of P, less than or equal to 0.015% of S and the balance Fe and unavoidable impurities. The novel high-strength LPD50 spring steel has the excellent characteristics of low carbon removed amount, high strength, high plasticity and toughness, low alloy content and low cost, and can meet the requirements on high stress, high fatigue property, high processing property and high reliability from lightweight flat springs.

Description

technical field [0001] The invention belongs to the field of high-strength spring steel for thermal pressure processing and its preparation technology, and specifically refers to the chemical composition, content and preparation method of a novel high-strength spring material. Background technique [0002] The lightweight of automobiles is the trend of automobile development. Among them, the advanced leaf spring technology of less leaf springs with variable cross-section (less leaf springs) is the main development direction of truck lightweight, which can reduce the weight of automobiles by more than 30%. At present, domestic few-leaf springs have not been widely used due to low fatigue performance. This is mainly because the material problem has not been effectively solved. Therefore, high-strength, low-alloy, high-plastic-toughness, low-decarburization and low-cost spring materials have been proposed. Requirements to meet the high stress, high fatigue performance, high pro...

AI Technical Summary

Problems solved by technology

At present, domestic few-leaf springs have not been widely used due to low fatigue performance. This is mainly because the material problem has not been effectively solved. Therefore, high-strength, low-alloy, high-plastic-toughness, low-decarburization and low-cost spring materials have been proposed. Requirements to meet the high stress, high fatigue performance, high process performance and high reliability requirements of lightweight and less leaf springs

[0003] The spring materials commonly used in the market are difficult to meet the requirements of low decarburization, high strength, high ductility, low alloy and low cost for a small number of variable cross-section leaf springs at the same time.

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

54SiCr6 has high strength and high ductility, but severe decarburization

South Korea’s POSCO spring steel (Chinese patent 94191328.7 disclosed) reduces the depth of the fully decarburized layer (ferrite layer) by adding Ni, but the addition of rare alloy elements leads to high material costs and is difficult to be accepted by the market

Images