CN-119040695-B - Seawater scouring corrosion resistant cast titanium alloy material and preparation method thereof

CN119040695BCN 119040695 BCN119040695 BCN 119040695BCN-119040695-B

Abstract

The invention provides a seawater erosion corrosion-resistant cast titanium alloy material and a preparation method thereof, and relates to the technical field of cast titanium alloy materials. The alloy material comprises, by mass, 5.8% -6.5% of Al,3.8% -4.5% of V,0.8% -1.5% of Zr,0.8% -1.5% of Nb,0.1% -0.3% of O,0.2% -0.5% of Fe and the balance of Ti. The preparation method comprises the steps of mixing titanium sponge, al beans, alV 58 、TiFe 32 、TiO 2 powder, alNb 70 powder and zirconium sponge serving as raw materials, pressing the raw materials into electrode blocks, assembling and welding the electrode blocks into strip electrodes, smelting the strip electrodes for multiple times and casting the strip electrodes to obtain alloy samples, cooling the casting, discharging the alloy samples from a furnace, and performing hot isostatic pressing treatment to obtain the titanium alloy samples. According to the invention, zirconium element, niobium element, and trace oxygen element and iron element are added into the titanium alloy, so that the seawater scouring corrosion resistance is greatly improved, and the design and manufacturing requirements of the seawater scouring-resistant large ship parts are met.

Inventors

KOU HONGCHAO
SONG YUQING
WANG GUODONG
GUO JINHONG

Assignees

西北工业大学

Dates

Publication Date: 20260508
Application Date: 20240909

Claims (4)

1. The seawater erosion corrosion resistant cast titanium alloy material is characterized by comprising, by mass, 5.8% -6.5% of Al,4.11% -4.5% of V,0.8% -1.5% of Zr,0.8% -1.5% of Nb,0.1% -0.3% of O,0.32% -0.5% of Fe and the balance of Ti; the alloy material has the yield strength of 750-780 MPa, the tensile strength of 835-870 MPa and the elongation of 13-15%, and the corrosion rate of the alloy material in 10m/s of flow rate seawater flushing is less than or equal to 0.0033mm/a.
2. A method of preparing a seawater flush corrosion resistant cast titanium alloy material as claimed in claim 1, said method comprising the steps of: S1, weighing titanium sponge, al beans, alV58, tiFe32, tiO 2 powder, alNb70 powder and zirconium sponge serving as raw materials according to the chemical composition ratio of the alloy material according to claim 1, mixing to obtain a mixed material, and pressing the mixed material into an electrode block through a press and a die; s2, assembling and welding the electrode blocks into strip-shaped electrodes; s3, smelting and casting the strip electrode obtained in the step S2 for a plurality of times to obtain an alloy sample; S4, pouring is completed, and discharging is carried out after the alloy sample is cooled; and S5, performing hot isostatic pressing treatment on the alloy sample obtained in the step S4 to obtain a final cast titanium alloy sample resistant to seawater erosion corrosion.
3. The method for producing a seawater flush corrosion resistant cast titanium alloy material according to claim 2, wherein the melting process of step S3 is performed in a vacuum consumable electrode arc melting furnace, and the resulting primary ingot is cast in a cold crucible suspension melting furnace or a vacuum skull furnace.
4. The method for preparing the seawater scouring corrosion resistant cast titanium alloy material according to claim 2, wherein the hot isostatic pressing parameter in the step S5 is as follows, the temperature is 910-930 ℃, the pressure is 110-130 MPa, and the time is 2-4 h.

Description

Seawater scouring corrosion resistant cast titanium alloy material and preparation method thereof Technical Field The invention belongs to the technical field of cast titanium alloy materials, and particularly relates to a seawater erosion corrosion-resistant cast titanium alloy material and a preparation method thereof. Background Titanium alloy castings have found wide application in various fields such as aerospace, marine engineering, shipbuilding, and petrochemical industry due to their good mechanical properties, lower density, excellent corrosion resistance, and relatively low processing cost. In recent years, stainless steel parts in large ship facilities have been replaced with pure titanium, titanium such as Ti-6Al-4V, and titanium alloys. The development of the titanium alloy material with more excellent strong plastic matching, seawater corrosion resistance and good casting process performance has important significance for improving the service reliability and durability of complex parts in the field of ocean engineering such as ships and the like. Among the cast titanium alloys commonly used in the ocean at present, the Ti-6Al-4V alloy has the most excellent comprehensive mechanical property. Some reports show that the novel low-cost high-plasticity seawater corrosion-resistant titanium alloy comprises, by weight, 3.0% -4.5% of Al, 2.0% -3.0% of V, 0.5% -1.5% of Fe, 0.5% -2.0% of Cu and the balance of Ti and unavoidable impurity elements. The alloy can obtain higher seawater corrosion resistance than Ti-6Al-4V alloy by adding Fe and Cu elements. However, this method has the disadvantage that the yield strength of the alloy can only reach 660MPa without subsequent heat treatment strengthening, and the strength is sacrificed to a greater extent than that of the Ti-6Al-4V alloy. Disclosure of Invention In order to solve the problems in the prior art, the invention introduces a small amount of Nb and Zr on the basis of the Ti-6Al-4V cast titanium alloy component with excellent fluidity widely used in the prior art, and improves the seawater scouring corrosion resistance of the alloy under the condition of ensuring the excellent casting performance of the alloy. The improvement not only prolongs the service life of the alloy in the marine environment, but also improves the reliability and stability of the alloy in the complex marine environment. In addition, the casting process performance of the alloy is equivalent to that of Ti-6Al-4V alloy, complex process steps can be avoided, and the alloy is suitable for low-cost manufacture of marine large-scale bearing components such as cast paddles and the like. Specifically, the first aspect of the invention provides a seawater erosion corrosion resistant cast titanium alloy material, which comprises, by mass, 5.8% -6.5% of Al,3.8% -4.5% of V,0.8% -1.5% of Zr,0.8% -1.5% of Nb,0.1% -0.3% of O,0.2% -0.5% of Fe and the balance of Ti. The second aspect of the invention provides a method for preparing the seawater scouring corrosion resistant cast titanium alloy material, which comprises the following steps: S1, weighing titanium sponge, al beans, alV 58、TiFe32、TiO2 powder, alNb 70 powder and zirconium sponge serving as raw materials according to the chemical composition ratio of the alloy material according to claim 1, mixing to obtain a mixed material, and pressing the mixed material into an electrode block through a press and a die; s2, assembling and welding the electrode blocks into strip-shaped electrodes; s3, smelting and casting the strip electrode obtained in the step S2 for a plurality of times to obtain an alloy sample; S4, pouring is completed, and discharging is carried out after the alloy sample is cooled; and S5, performing hot isostatic pressing treatment on the alloy sample obtained in the step S4 to obtain a final cast titanium alloy sample resistant to seawater erosion corrosion. As a further illustration of the invention, the smelting process of step S3 is first completed in a vacuum consumable electrode arc melting furnace, and the resulting primary ingot is poured in a cold crucible suspension melting furnace or a vacuum skull furnace. As a further illustration of the invention, the hot isostatic pressing parameters of step S5 are as follows, the temperature is 910 ℃ to 930 ℃, the pressure is 110 to 130MPa, and the time is 2 to 4 hours. Compared with the prior art, the invention has the following beneficial technical effects: In the invention, zirconium element, niobium element, trace oxygen element and iron element are added into titanium alloy, and the mass percentage of Zr element is controlled to be 0.8% -1.5%, nb element is controlled to be 0.8% -1.5%, O element is controlled to be 0.1% -0.3%, and Fe element is controlled to be 0.2% -0.5%. Compared with Ti-6Al-4V alloy, the alloy of the invention greatly improves the seawater scouring corrosion resistance and meets the design and manufacturing requirements of large ship parts which