Hardenability-remaining high-strength low-temperature toughness spring steel

Abstract

The invention relates to hardenability-remaining high-strength low-temperature toughness spring steel, which belongs to the technical field of alloy steel. The technical scheme is that chemical components are as follows, by weight percentage, 0.56-0.64% of C, 1.40-2.00% of Si, 0.40-0.80% of Mn, 0.70-1.00% of Cr, 0.10-0.40% of Ni, Cu<=0.25%, P<=0.025%, S<=0.025% and the balance Fe and impurities. Tempering tensile strength of the spring steel >=1750Mpa, the temperature of the spring steel is 880+ / -20 DEG C before quenching, and after quenching the temperature is 430+ / -50 DEG C. Aku2>=20J at normal temperature or at the temperature of -40 DEG C, the Aku2 is impact energy of a 2mm U-shaped notch, and the unit is J. In an end-quenching test, J20>=55HRC, J20 represents hardness of a position in the end-quenching test 20mm away from a water spraying end, and the unit is HRC. The hardenability-remaining high-strength low-temperature toughness spring steel has the advantages of improving hardenability of steel and impact toughness and being especially suitable for manufacturing a cylindrical spiral spring with specification <=phi50 mm.

Description

technical field [0001] The invention relates to a high-strength low-temperature ductile spring steel with hardenability, which belongs to the technical field of alloy steel. Background technique [0002] At present, the working stress of large-tonnage construction machinery is relatively large, and the regional differences in use have put forward new requirements for the impact performance of parts, especially for spring steel used in tensioning mechanisms. It still has high impact performance under the condition of 40°C. Spring steel for construction machinery has a large specification, usually φ40-φ60mm. It has good hardenability and high strength, and a certain room temperature impact performance is the basic condition of steel. It has been achieved by adding trace elements, but it has the above properties at the same time- It has high impact performance under the condition of 40 ℃, and it is a new subject to be economical. Background Art The large-scale round steel...

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Problems solved by technology

Background Art The large-scale round steel materials used to make coil springs include 60Si2CrA, 60Si2CrVA, 60CrMnBA, and SUP11A. Chinese patent ZL200510018800.7 is named "high-strength toughness and high hardenability spring steel", and ZL200710052805.0 is named "a kind of High-stress, high-plasticity, high-hardenability large-section spring steel", ZL200380100602.4, titled "Spring steel with improved hardenability and pitting resistance"; the hardenability of the above materials is relatively large, All are suitable for springs with large cross-sectional diameters of different sizes, but none of them can guarantee high hardenability and high strength while ensuring the low temperature toughness of the material

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