A kind of dual-phase steel for 850mpa wheel spoke and preparation method thereof

Abstract

The invention provides a dual-phase steel for 850MPa wheel spokes and a preparation method thereof, belonging to the technical field of dual-phase steels for wheel spokes. The dual-phase steel is composed of the following chemical components in mass fractions, C: 0.08-0.10%, Si: 0.10‑0.20%, Mn: 1.65‑1.85%, P≤0.010%, S≤0.005%, Als: 0.3‑0.5%, Cr: 0.51‑0.70%, Nb: 0.041‑0.060%, Ti: 0.01‑0.03 %, the balance is Fe and unavoidable impurities; the metallographic structure of the dual-phase steel consists of acicular ferrite and martensite. The dual-phase steel provided by the invention has a tensile strength of 855-875 MPa, an elongation of 18-22%, good formability, a low yield ratio of 0.73-0.78, 180° transverse and longitudinal cold bending, and fatigue strength limit 470‑481MPa, good fatigue strength, circumference deviation 0‑0.5mm, small rebound, good performance.

Description

technical field [0001] The invention belongs to the technical field of dual-phase steel for wheel spokes, and in particular relates to a dual-phase steel for 850MPa wheel spokes and a preparation method thereof. Background technique [0002] Automobile spokes mostly use high-strength dual-phase steel as raw materials. With the clear development trend of vehicle weight reduction and material strength upgrading, automobile structural parts manufacturers have stepped up research and development of lightweight products to seize lightweight auto parts. market. Among them, the wheel spoke as an auto part has also accelerated the pace of research and development. At present, the production and processing of the lightweight tubeless wheel spoke of commercial vehicles requires complex spinning deformation. For a 30kg 22.5×9.0J commercial vehicle wheel spoke, the thickness of some parts is thinned It can reach more than 50%, and the hardness is increased by about 50%. It is easy to c...

AI Technical Summary

Problems solved by technology

Among them, the wheel spoke as an auto part has also accelerated the pace of research and development. At present, the production and processing of the lightweight tubeless wheel spoke of commercial vehicles requires complex spinning deformation. For a 30kg 22.5×9.0J commercial vehicle wheel spoke, the thickness of some parts is thinned It can reach more than 50%, and the hardness is increased by about 50%. It is easy to crack during spinning, which wastes resources and affects the production rhythm.

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