A 500mpa grade low yield ratio high corrosion resistance hot-dip galvanized low density steel and manufacturing method
By adjusting the distribution of δ-ferrite and controlling the distribution of MnS and RE-SO, a 500MPa grade hot-dip galvanized low-density steel with low yield strength ratio and high corrosion resistance was prepared. This solved the problems of high yield strength ratio and large springback in the existing technology, and improved the formability and corrosion resistance of automotive parts.
CN121759810BActive Publication Date: 2026-05-15ANGANG STEEL CO LTD
3 Cites 0 Cited by
Patent Information
- Application Number
- CN202610246026.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-02
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2046-03-02
AI Technical Summary
Technical Problem
Existing low-density steel has a high yield strength ratio and high springback, which makes it difficult to meet the requirements of lightweighting in automobiles.
Method used
By adjusting the distribution of δ-ferrite and using specific chemical compositions and process steps, a microstructure of δ-ferrite + martensite + retained austenite + sulfides is prepared, controlling the distribution of MnS and RE-SO, reducing yield strength and improving corrosion resistance.
Benefits of technology
It achieves a yield strength ratio ≤0.638, tensile strength ≥500MPa, elongation ≥29%, reduces springback of parts, and improves the formability and corrosion resistance of products.
✦ Generated by Eureka AI based on patent content.
Abstract
The application provides a 500MPa-grade low-yield-ratio high-corrosion-resistance hot-dip galvanized low-density steel and a manufacturing method, and the steel plate composition is as follows in percentage by weight: C: 0.065%-0.073%, Si: 0.42%-0.54%, Mn: 1.51%-1.62%, Al: 3.3%-6.5%, P: <=0.010%, S: 0.01-0.03%, RE: 0.01%-0.015%, and the balance is Fe and inevitable impurities. The manufacturing method of the steel comprises the following steps: blast furnace molten iron pretreatment, converter steelmaking, continuous casting, hot continuous rolling, pickling, cold rolling, hot-dip galvanizing; and the steel organization structure is as follows: delta-ferrite + martensite + residual austenite + sulfide, wherein the martensite content is 5.2%-7.0%, the residual austenite content is 3.5%-3.8%, and the sulfide composition is a small amount of dispersedly distributed MnS and RE-S-O, a small amount of MnS is dispersedly precipitated in ferrite and martensite, and RE-S-O is distributed along the ferrite grain boundary.
Need to check novelty before this filing date? Find Prior Art