A kind of nickel-chromium-molybdenum-containing marine splash zone pitting corrosion resistant corrosion-resistant stainless steel material and preparation process

By designing a nickel-chromium-molybdenum chemical composition and employing a specialized preparation process, the corrosion resistance and mechanical properties of stainless steel materials in marine splash zones have been addressed. This process forms a stable passivation film and a multi-layered protective structure, enhancing the material's corrosion resistance and mechanical properties and extending the service life of marine engineering structures.

CN122168981APending Publication Date: 2026-06-09INST OF OCEANOLOGY - CHINESE ACAD OF SCI +1
View PDF 0 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
INST OF OCEANOLOGY - CHINESE ACAD OF SCI
Filing Date
2026-04-10
Publication Date
2026-06-09

AI Technical Summary

Technical Problem

Existing stainless steel materials have insufficient resistance to pitting corrosion when used in marine splash zones. The passivation film is easily penetrated by chloride ions, leading to corrosion damage. Furthermore, it is difficult to balance corrosion resistance and mechanical properties. The manufacturing process also suffers from compositional inhomogeneity and inclusion problems.

Method used

The chemical composition is designed with nickel, chromium, and molybdenum, and combined with vacuum induction melting, electroslag remelting, hot working and surface treatment processes to form a stable passivation film and multi-layer protective structure, ensuring compositional uniformity and internal material quality, and improving corrosion resistance and mechanical properties.

Benefits of technology

It significantly improves the material's resistance to pitting corrosion in the ocean splash zone, extends its service life, and balances excellent corrosion resistance stability with tensile strength and toughness. It also reduces the risk of chloride ions damaging the passivation film and reduces corrosion initiation points.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

This invention relates to the field of stainless steel materials technology, specifically to a nickel-chromium-molybdenum-containing marine splash zone-resistant and corrosion-inhibiting stainless steel material and its preparation process. The chemical composition of the stainless steel material, by mass percentage, includes: carbon ≤0.04%, silicon 0.5%-0.8%, manganese ≤0.8%, phosphorus ≤0.02%, sulfur ≤0.0015%, chromium 22%, nickel 10%-11%, molybdenum 3.0%-3.5%, copper 1.2%-1.5%, titanium 0.2%-0.25%, niobium 0.1%-0.15%, with the remainder being iron. This invention's stainless steel material, through scientific chemical composition design, constructs a stable basic corrosion-resistant system. Simultaneously, the introduction of specific elements exerts a synergistic effect, effectively enhancing the stability and density of the passivation film on the material surface. This significantly improves the material's resistance to pitting corrosion in marine splash zones, reduces the risk of chloride ion damage to the passivation film, effectively inhibits intergranular corrosion, greatly improves the material's corrosion resistance stability, and extends its service life in harsh marine environments.
Need to check novelty before this filing date? Find Prior Art

Claims

1. A nickel-chromium-molybdenum-containing stainless steel material resistant to pitting corrosion in marine splash zones, characterized in that, The chemical composition of the stainless steel material, by mass percentage, includes: carbon ≤0.04%, silicon 0.5%-0.8%, manganese ≤0.8%, phosphorus ≤0.02%, sulfur ≤0.0015%, chromium 22%, nickel 10%-11%, molybdenum 3.0%-3.5%, copper 1.2%-1.5%, titanium 0.2%-0.25%, niobium 0.1%-0.15%, with the remainder being iron.

2. A process for preparing the stainless steel material according to claim 1, characterized in that, Includes the following steps: (1) Melting: Vacuum induction melting is performed first, followed by electroslag remelting; the vacuum degree of the vacuum induction melting is 5×10 -3 Pa, the melting temperature is 1550℃-1580℃, the holding time is 40 minutes; the slag system of the electroslag remelting is CaF2-CaO-Al2O3, the current is 450A, the voltage is 32V, the cooling water temperature is 25℃, the holding time is 40 minutes-45 minutes, and an ingot is obtained. (2) Hot working: The ingot obtained in step (1) is heated to 1120℃, held for 2 hours and then forged. The reduction is 30%-35% / pass, for a total of 3 passes, and rolled into a plate. The final rolling temperature is 950℃. (3) Heat treatment: first solution treatment, then aging treatment; the solution treatment temperature is 1050℃, the holding time is 2 hours to 2.5 hours, and the water quenching cooling rate is 50℃ / s; the aging treatment temperature is 450℃, the holding time is 3 hours, and air cooling is used. (4) Surface treatment: passivate by soaking in a mixture of nitric acid and hydrofluoric acid at room temperature for 30 minutes, then rinse with deionized water at 40°C, and finally air dry at room temperature.

3. The stainless steel material according to claim 1, characterized in that, The carbon content is 0.04% by mass percentage.

4. The stainless steel material according to claim 1, characterized in that, The silicon content is 0.5% or 0.8% by mass percentage.

5. The stainless steel material according to claim 1, characterized in that, The manganese content is 0.8% by mass percentage.

6. The stainless steel material according to claim 1, characterized in that, The phosphorus content is 0.02% by mass percentage, and the sulfur content is 0.001%.

7. The stainless steel material according to claim 1, characterized in that, The nickel content is 10% or 11% by mass percentage, and the molybdenum content is 3.0% or 3.5%.

8. The stainless steel material according to claim 1, characterized in that, The copper content is 1.2% or 1.5% by mass percentage, the titanium content is 0.2% or 0.25%, and the niobium content is 0.1% or 0.15%.

9. The preparation process according to claim 2, characterized in that, In step (1), the temperature of the vacuum induction melting is 1550℃ or 1580℃, and the holding time of the electroslag remelting is 40 minutes or 45 minutes.

10. The preparation process according to claim 2, characterized in that, In step (2), the forging reduction is 30% / pass or 35% / pass; in step (3), the heat preservation time of the solution treatment is 2 hours or 2.5 hours; in step (4), the mass fraction of nitric acid in the mixture is 15%, the mass fraction of hydrofluoric acid is 2%, and the passivation process also includes a silane sealing treatment step of soaking in γ-aminopropyltriethoxysilane solution at room temperature for 1 hour.