Alloy material resistant to acid and alkali corrosion, preparation method and product thereof

Abstract

The application discloses an alloy material resistant to acid and alkali corrosion and a preparation method and products thereof, and the alloy material is composed of 20.5-21.0 wt% Cr, 6.0-6.5 wt% Mo, 17.5-18.5 wt% Ni, 0.18-0.22 wt% N, 0.8-1.2 wt% Cu, 0.05-0.1 wt% Ce, ≤0.02 wt% C and the balance of Fe and inevitable impurities. Through multidirectional synergistic design, the core requirements of excellent corrosion resistance, high strength and long service life under strong acid / alkali and high stress working conditions are realized, and the alloy material is particularly suitable for precision ball screw support bearings in harsh environments such as semiconductor cleaning equipment.

Description

Technical Field

[0001] This invention belongs to the field of alloy materials technology, specifically relating to an acid and alkali resistant alloy material, its preparation method, and the product thereof. Background Technology

[0002] The bearings in semiconductor cleaning equipment need to be resistant to acids and alkalis, mainly for the following core reasons: Semiconductor cleaning processes often use highly corrosive chemical solutions, and the bearings may come into direct or indirect contact with the following media: hydrofluoric acid, sulfuric acid, hydrochloric acid, etc., used to remove oxides and metal contaminants; ammonia, SC1 solution, used to remove organic residues and particles; hydrogen peroxide, ozone water, etc., used for photoresist stripping and surface activation.

[0003] If the bearing material is not corrosion-resistant, chemical corrosion will occur. For example, stainless steel bearings will develop iron fluoride in HF, leading to pitting corrosion and metal ion contamination (Fe). 3+ Cr 3+ Metal particles or oxide flakes (such as Fe2O3) generated after bearing corrosion can adhere to the wafer surface with the cleaning solution, leading to short circuits, dielectric layer defects, etc., affecting chip yield (requiring metal impurities ≤1 ppb).

[0004] In the existing technology, commonly used corrosion-resistant bearing materials include ceramic bearings, which are resistant to all acids and alkalis except HF, but are expensive; and Hastelloy C-276, which is resistant to HF, but is also expensive.

[0005] Chinese patent application number 201510525667.8 discloses an acid and alkali corrosion resistant alloy steel, which is composed of the following weight components: carbon 0.15-0.27%, silicon 0.25-0.46%, boron 0.12-0.18%, aluminum 0.05-0.14%, titanium 0.16-0.22%, cobalt 0.04-0.09%, antimony 0.5-1.2%, chromium 0.6-1.8%, zinc 0.4-1.3%, copper 0.05-0.8%, composite rare earth elements 0.04-0.1%, phosphorus <0.03%, sulfur <0.03%, and the balance being iron. The alloy steel of this invention exhibits significantly improved acid and alkali corrosion resistance, exceeding that of ordinary alloy steel by more than five times, while also exhibiting lower brittleness and relatively lower production costs.

[0006] Chinese patent application number 2024103636584.2 discloses a stainless steel for fuel cell plates and a method for surface modification thereof. The stainless steel has the following elemental composition: Cr: 20-30%, Ni: 0-20%, Mo: 3-10%, N: 0.05-1.5%, C: 0-0.03%, Si: 0-0.6%, Mn: 0-0.5%, Nb: 0-0.5%, W: 0-0.2%, Sn: 0-1%, Au: 0-0.5%, Ta: 0-0.5%, Al: 0-0.02%, Cu: 0-0.2%, P: 0-0.05%, S: 0-0.05%, Ce: 0-0.1%, with Fe making up the balance. The process involves removing the passivation film and impurities from the stainless steel surface and generating a new passivation film; the self-corrosion current density can be less than 1 μA / cm². 2 It also has excellent electrical conductivity, but the corrosion resistance of this material was only tested under acidic conditions, and it cannot be determined whether it can meet the application scenarios that require both acid and alkali resistance. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention proposes a novel acid and alkali resistant bearing alloy material that can be used to manufacture semiconductor cleaning equipment. The specific technical solution of this invention is as follows:

[0008] The first technical solution of the present invention is as follows:

[0009] An acid and alkali resistant alloy material, comprising 20.5-21.0 wt% Cr, 6.0-6.5 wt% Mo, 17.5-18.5 wt% Ni, 0.18-0.22 wt% N, 0.8-1.2 wt% Cu, 0.05-0.1 wt% Ce, ≤0.02 wt% C and the balance Fe and unavoidable impurities, wherein O in Fe ≤500 ppm.

[0010] An alloy material for ball screw support bearings resistant to acid and alkali corrosion, comprising 20.5-21.0 wt% Cr, 6.0-6.5 wt% Mo, 17.5-18.5 wt% Ni, 0.18-0.22 wt% N, 0.8-1.2 wt% Cu, 0.05-0.1 wt% Ce, ≤0.02 wt% C and the balance Fe, wherein O in Fe ≤500 ppm.

[0011] Furthermore, the alloy material contains ≥7wt% Mo+Cu and a Cr / Ni mass ratio of 1.1-1.2. The core of Mo+Cu ≥7wt% lies in utilizing the synergistic effect of Mo-Cu to enhance the passivation film's repair capability and density; a Cr / Ni ratio of 1.1-1.2 can optimize the oxide film's chemical composition (NiCr2O4 spinel phase) and phase stability, achieving comprehensive corrosion resistance.

[0012] Furthermore, the pitting equivalent of this alloy material is 43.18–45.97. This is calculated based on the formula: Pitting Equivalent = %Cr + 3.3 × %Mo + 16 × %N.

[0013] Furthermore, the grain size of this alloy material is ASTM 9-10.

[0014] A method for preparing the aforementioned acid and alkali resistant alloy material includes the following steps:

[0015] Step 1: Load 18.3-19.2wt%Cr, 6.0-6.5wt%Mo, 17.5-18.5wt%Ni, 0.8-1.2wt%Cu, 0.05-0.1wt%Ce, ≤0.02wt%C and 51.5-54.2wt%Fe into the furnace;

[0016] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 pa;

[0017] Step 3: Heat to melt the raw material. First, preheat at 600℃ for 20 minutes, then melt at 1520±10℃ for ≤30 minutes to avoid burning of Cr or Mo.

[0018] Step 4: Add 2.8-3.4 wt% FeCrN, stir for 12-15 minutes, maintain the furnace temperature at 1550±10℃, use a nitrogen-argon mixed gas (90% Ar + 10% N2) for environmental control, and blow argon from the bottom to stir the melt and promote FeCrN melting. Maintain a slight positive pressure of 0.1 MPa in the furnace to avoid nitrogen loss. Preferably, FeCrN-6.5 is used, and it can be added in two batches. The first batch contains 60% of the total amount, and the remaining FeCrN is added after an interval of 2-3 minutes to ensure uniform melting.

[0019] Step 5: Cast the electrode rod.

[0020] Furthermore, all raw materials in step 1 must be sandblasted, ultrasonically cleaned with alcohol for 10 minutes, and then dried at 80°C for 2 hours. The furnace loading sequence is as follows: first load refractory metals (Mo, Fe), then fusible metals (Ni, Cu, Cr), and finally add Ce wrapped in foil.

[0021] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 The procedure for pumping Pa is as follows: First, the mechanical pump is pre-pumped to ≤10 Pa; then, the diffusion pump is switched, and after heating to the operating temperature, the pumping is reduced to ≤5 × 10 Pa. -3 Pa; Finally, pressure holding test: leakage rate ≤ 0.02 Pa / min. Equipment requirements: oil diffusion pump + cold trap, equipped with ionization vacuum gauge to monitor vacuum level.

[0022] Step 5: Casting the electrode rod. Casting conditions: Mold preheating: Preheat the graphite mold to 600℃ to reduce thermal stress; Casting temperature: 1550±5℃; Speed: Inclined casting (30° angle), flow rate 2-3 kg / s; Cooling parameters: Argon protection cooling to 800℃, cooling rate 50℃ / s. Rapid cooling is used here to refine the grains, reduce segregation, and improve strength; Subsequently, air cooling to room temperature. The resulting electrode specifications are: Φ80×500mm, and the surface is machined (Ra≤3.2μm).

[0023] To further reduce the surface activity of the alloy material and improve its corrosion resistance, this invention also provides a second technical solution: an acid and alkali resistant alloy material, which is composed of 20.5-21.0 wt% Cr, 6.0-6.5 wt% Mo, 17.5-18.5 wt% Ni, 0.18-0.22 wt% N, 0.8-1.2 wt% Cu, 0.05-0.1 wt% Ce, ≤0.02 wt% C, and the balance Fe and unavoidable impurities. The surface of the alloy material contains a passivation layer, which is obtained by passivating the alloy material. The passivation solution is 10% citric acid + 10% hydrogen peroxide + 0.05% cerium chloride + 1% sodium molybdate. The passivation process is as follows: first, the material is kept at 60°C for 30 minutes to form a film, then kept at 40°C for 20 minutes. After passivation, the material is neutralized, washed with water, and dried under nitrogen protection at 80°C. The passivation layer obtained by passivation treatment has a three-layer structure. The outermost layer is an organic layer, mainly composed of citric acid-Cr complex, which acts as a hydrophobic barrier. The middle transition layer is composed of CrOOH+Fe2O3+Ni(OH)2, which acts as a stress buffer and inhibits interfacial peeling. The doped oxide layer, mainly composed of Cr2O3+MoO2+CeO2, is a corrosion-resistant layer that blocks ion penetration.

[0024] Furthermore, the content of Mo+Cu in the alloy material is ≥7wt%, and the mass ratio of Cr / Ni is 1.1-1.2.

[0025] Furthermore, the pitting equivalent of this alloy material is 43.18–45.97.

[0026] Furthermore, the grain size of this alloy material is ASTM 9-10.

[0027] The preparation method of the acid and alkali corrosion resistant alloy material containing a passivation layer in this scheme is as follows:

[0028] Step 1: Load 18.3-19.2wt%Cr, 6.0-6.5wt%Mo, 17.5-18.5wt%Ni, 0.8-1.2wt%Cu, 0.05-0.1wt%C, ≤0.02wt%C and 51.5-54.2wt%Fe into the furnace;

[0029] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 pa;

[0030] Step 3: Heat to melt the raw material. First, preheat at 600℃ for 20 minutes, then melt at 1520±10℃ for ≤30 minutes to avoid burning of Cr or Mo.

[0031] Step 4: Add 2.8-3.4 wt% FeCrN, stir for 12-15 minutes, maintain the furnace temperature at 1550±10℃, use a nitrogen-argon mixed gas (90% Ar + 10% N2) for environmental control, and blow argon from the bottom to stir the melt and promote FeCrN melting. Maintain a slight positive pressure of 0.1 MPa in the furnace to avoid nitrogen loss. Preferably, FeCrN-6.5 is used, and it can be added in two batches. The first batch contains 60% of the total amount, and the remaining FeCrN is added after an interval of 2-3 minutes to ensure uniform melting.

[0032] Step 5: Casting electrode rods;

[0033] Step 6: After machining and surface treatment of the prepared electrode rod, passivation treatment is performed. The passivation solution is 10% citric acid + 10% hydrogen peroxide + 0.05% cerium chloride + 1% sodium molybdate. Specifically, the passivation solution uses water as a solvent, wherein the mass fraction of citric acid is 10%, the mass fraction of hydrogen peroxide is 10%, the mass fraction of cerium chloride is 0.05%, and the mass fraction of sodium molybdate is 1%. Passivation process: First, maintain at 60℃ for 30 minutes to form a film, then maintain at 40℃ for 20 minutes to solidify the hydrophobic layer. After passivation, neutralize and wash with water, then dry under nitrogen protection at 80℃.

[0034] Preferably, 0.1 wt% sodium citrate, a pH stabilizer, can also be added to the passivation solution. Furthermore, 0.1-0.5 wt% graphene or PTFE nanoparticles can be added to the passivation solution. Introducing graphene or PTFE nanoparticles into the organic layer can improve wear resistance and extreme pH stability.

[0035] Furthermore, all raw materials in step 1 must be sandblasted, ultrasonically cleaned with alcohol for 10 minutes, and then dried at 80°C for 2 hours. The furnace loading sequence is as follows: first load refractory metals (Mo, Fe), then fusible metals (Ni, Cu, Cr), and finally add Ce wrapped in foil.

[0036] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 The procedure for pumping Pa is as follows: First, the mechanical pump is pre-pumped to ≤10 Pa; then, the diffusion pump is switched, and after heating to the operating temperature, the pumping is reduced to ≤5 × 10 Pa. -3 Pa; Finally, pressure holding test: leakage rate ≤ 0.02 Pa / min. Equipment requirements: oil diffusion pump + cold trap, equipped with ionization vacuum gauge to monitor vacuum level.

[0037] Step 5: Casting electrode rods. Casting conditions: Mold preheating: Preheat graphite mold to 600℃ to reduce thermal stress; Casting temperature: 1550±5℃; Speed: Inclined casting (30° angle), flow rate 2-3 kg / s; Cooling parameters: Argon protection cooling to 800℃, cooling rate 50℃ / s, followed by air cooling to room temperature. Preferably, 800℃-400℃, cooling rate 20℃ / s, air cooling below 400℃. Final electrode specifications: Φ80×500mm, surface turned (Ra≤3.2μm).

[0038] The passivation layer on the surface of the passivated alloy material has a three-layer structure. The outermost layer is an organic layer, mainly composed of citric acid-Cr complex, which acts as a hydrophobic barrier. The middle transition layer is composed of CrOOH+Fe2O3+Ni(OH)2, which acts as a stress buffer and inhibits interfacial peeling. The doped oxide layer is composed of Cr2O3+MoO2+CeO2, which is the main anti-corrosion layer and blocks ion penetration.

[0039] The applicant believes that the passivation process may form a multilayer structure through the following mechanism: First, the organic layer is mainly a citric acid-Cr complex. Citric acid (weakly acidic) in the passivation solution acts as an excellent chelating agent, and multiple carboxyl and hydroxyl groups on the citric acid molecule rapidly coordinate with the most surface-active metal atoms (mainly Cr), forming a citric acid-Cr complex adsorption layer. Under the oxidation of 60℃ and H2O2, this complex may undergo partial decarboxylation and / or oxidative polymerization, forming an ultrathin, cross-linked organic polymer network film. Second, in the transition layer, in the weakly acidic environment provided by citric acid, the Fe and Ni elements with high electrochemical activity on the alloy surface will selectively dissolve in the micro-anodic region, with Fe... 2+ Ni 2+Ions enter the solution boundary layer immediately adjacent to the alloy surface. This process dynamically competes with subsequent passivation formation and does not occur after the formation of a dense inner layer, but rather in the initial stage of film formation. OH - Ion generation (core mechanism): This is crucial for the formation of the hydroxide intermediate layer and is one of the most ingenious chemical principles in this process design. OH - Mainly derived from H2O2 in Ce 3+ / Ce 4+ Decomposition under catalytic cycling, Ce in solution 3+ It undergoes a Fenton-like reaction with H2O2: H2O2 + Ce 3+ → Ce 4 + ·OH + OH - This catalytic cycle continuously generates highly active ·OH radicals and high concentrations of OH radicals near the alloy surface. - The presence of ions leads to a significant increase in local pH. Locally enriched Fe... 2+ Ni 2+ And a small amount of dissolved Cr 3+ Ions, in the high concentration of OH produced by the above reaction - Under the influence of the substance, it rapidly reaches its solubility product and precipitates: Fe 2+ +2OH - → Fe(OH)2 (subsequently oxidized by H2O2 to the more stable Fe2O3), Ni 2+ +2OH - → Ni(OH)2, Cr 3+ +3OH - → Cr(OH)3 (partially dehydrated to form CrOOH). These newly formed hydroxide / oxide nanoparticles undergo heterogeneous nucleation and growth beneath the existing organic complex layer or in its micropores, intercalating to form a mixed, dense intermediate transition layer; finally, a doped oxide layer is formed, where abundant Cr and Mo elements in the alloy matrix undergo in-situ oxidation directly at the metal / film interface under the strong oxidizing effect of H2O2. The presence of Mo significantly promotes Cr passivation, and the MoO4 provided by sodium molybdate... 2- Ions are reduced and doped into the Cr₂O₃ lattice as molybdenum oxide, forming a more stable Cr-Mo composite oxide layer (Cr₂O₃ + MoO₂). During the formation of the transition layer, H₂O₂ + Ce₂... 3+ Ce generated by the reaction 4+ The ions are extremely unstable and will rapidly hydrolyze and deposit into ultrafine CeO2 nanoparticles. 4+ +2H₂O →CeO₂(s)+4H +These CeO2 nanoparticles fill the grain boundaries and pores of the growing Cr-Mo oxide layer, acting as both "physical pinning" and "filling" particles, significantly improving the layer's density and resistance to ion penetration. Simultaneously, Ce... 3+ / Ce 4+ The presence of redox couples endows the passivation film with a certain chemical repair capability when it encounters local damage. Through the above three-stage sequential reaction, a functionally graded composite film is finally formed on the alloy surface. The outer organic layer provides a hydrophobic barrier, isolating most aqueous media; the intermediate transition layer, due to its flexible hydroxide phase and the volume difference of different oxides, plays a role in buffering stress and inhibiting interlayer delamination; the innermost Cr-Mo-Ce ternary composite oxide layer is the core anti-corrosion barrier that blocks the penetration of corrosive ions.

[0040] The present invention also provides a third technical solution. When the alloy material is used to manufacture high-load components such as bearings, based on the alloy described in the second technical solution, a Ce-O modified passivation film is added to the surface of the passivation layer. The preparation method is based on the preparation method in the second technical solution of the present invention and further includes step 7: sealing treatment, immersing in 0.05% Ce(NO3)3 melt at 80°C for 20-30 minutes to form a Ce-O modified passivation film on the surface of the passivation layer, thereby obtaining an acid and alkali corrosion resistant ball screw support bearing alloy material, which is composed of 20.5-21.0wt%Cr, 6.0-6.5wt%Mo, 17.5-18.5wt%Ni, 0.18-0.22wt%N, 0.8-1.2wt%Cu, 0.05-0.1wt%Ce, ≤0.02wt%C and the balance Fe and unavoidable impurities. The surface of the alloy material has a Ce-O modified passivation film.

[0041] An article made from the aforementioned acid and alkali resistant alloy material is a bearing, which can be used as a ball screw support bearing. Specifically, the alloy bar is cold-forged or hot-forged, then rough-ground and quenched, followed by fine-ground, polished, and inspected.

[0042] The functions of each alloy raw material in this invention are as follows:

[0043] Cr is the core element for forming a dense Cr2O3 passivation film, providing basic corrosion resistance, especially in acidic environments, where a high Cr content (>20%) can significantly improve resistance to pitting corrosion. In some embodiments, the Cr content can be 20.5 wt%, 20.7 wt%, 20.9 wt%, or 21 wt%, or any value between two of these.

[0044] Mo (6.0-6.5 wt%) enhances resistance to localized corrosion (pitting corrosion, crevice corrosion) and synergistically improves the PREN value with Cr / N. In some embodiments, the Mo content can be 6.0 wt%, 6.1 wt%, 6.2 wt%, 6.3 wt%, 6.4 wt%, or 6.5 wt%, or any value between two of these.

[0045] Ni (17.5-18.5 wt%): Stabilizes the austenitic phase, preventing it from transforming into martensite during cold working or welding, maintaining toughness, and improving resistance to reducing acids (such as dilute sulfuric acid). In some embodiments, the Ni content can be 17.5 wt%, 17.8 wt%, 18 wt%, 18.2 wt%, or 18.5 wt%, or any value between two of these.

[0046] N (0.18-0.22 wt%): In this application, nitrogen is added to the melt in the form of FeCrN under argon protection at 1550±10℃. Efficient solid solution of 0.18-0.22 wt% nitrogen is achieved by precisely controlling the holding time. This method addresses the triple requirements of semiconductor materials for compositional precision, corrosion resistance, and toughness. Its solid solution strengthening contribution exceeds 400 MPa, while the grain boundary stabilizing effect of nitrogen increases the bearing life by more than three times in acidic and alkaline environments. In some embodiments, the N content can be 0.18 wt%, 0.2 wt%, or 0.22 wt%, or any value between two of these.

[0047] Cu (0.8-1.2 wt%): Improves resistance to sulfuric acid and phosphoric acid corrosion and promotes passivation film repair. In some embodiments, the Cu content can be 0.8 wt%, 1 wt%, or 1.2 wt%, or any value between two of these.

[0048] Ce (0.05-0.1wt%): Rare earth elements refine grains, purify grain boundaries (sulfide inclusion modification), and improve high-temperature oxidation resistance. In some embodiments, the Ce content can be 0.05wt%, 0.08wt%, or 0.1wt%, or any value between two of these.

[0049] Ultra-low carbon (≤0.02wt% C): Prevents carbon from forming carbides with Cr, thus preventing sensitization to intergranular corrosion.

[0050] The combination of Cu (resistant to sulfuric acid corrosion) and Ce (refined grains + promoted passivation film repair) fills the gap in bearing materials for acidic environments; ultra-low C (≤0.02%) + controlled N: while avoiding intergranular corrosion, the strength loss due to C deficiency is compensated by N solid solution strengthening.

[0051] The alloy of this invention is strengthened by a Cr / Mo / Ni passivation film, with Mo+Cu resisting reducing acids and Ce purifying grain boundaries, achieving corrosion resistance in all acid and alkali environments through elemental synergy. The Cr+Mo+N synergistic effect inhibits localized corrosion, optimizes pitting corrosion equivalent, and meets stability requirements in high chloride ion environments. The surface hydrophobic layer in the passivation layer addresses the insufficient hydrophobicity of traditional passivation films. The transition layer (which buffers stress with hydroxides and inhibits film peeling) and the main anti-corrosion layer utilize the oxygen vacancy repair capability of CeO2 and the Cl- oxidizing ability of MoO2... - Adsorption inhibition forms a "self-repairing" barrier.

[0052] This application achieves the core requirements of excellent corrosion resistance, high strength and long service life under strong acid / alkali and high stress conditions through multi-faceted collaborative design, making it particularly suitable for precision ball screw support bearings in harsh environments such as semiconductor cleaning equipment. Attached Figure Description

[0053] Figure 1 The metallographic image of the alloy obtained in Example 1 of this invention;

[0054] Figure 2 The metallographic image of the alloy obtained in Example 2 of this invention;

[0055] Figure 3 The metallographic image of the alloy obtained in Example 3 of this invention;

[0056] Figure 4 This is a design diagram for the cyclic test of the present invention;

[0057] Figure 5 This is a photograph of the ball screw support bearing obtained in Embodiment 5 of the present invention. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0060] In the description of this invention, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0061] Example 1

[0062] Prepare acid and alkali resistant alloy materials according to the following steps:

[0063] Step 1: Load 20.5wt%Cr, 6.5wt%Mo, 17.5wt%Ni, 1wt%Cu, 0.05wt%C, ≤0.02wt%C and 54.5wt%Fe into the furnace. The loading order is as follows: first load the refractory metals (Mo, Fe), then load the fusible metals (Ni, Cu, Cr). Ce is wrapped in foil and added last. In particular, all raw materials need to be sandblasted and ultrasonically cleaned with alcohol for 10 minutes, and then dried at 80℃ for 2 hours.

[0064] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 The operating procedure is as follows: 1. Pre-pump with a mechanical pump to ≤10 Pa; 2. Switch to a diffusion pump, heat to the operating temperature, and then pump to ≤5×10 Pa. -3 3. Pressure holding test: Leakage rate ≤ 0.02 Pa / min;

[0065] Step 3: Heat to melt the raw materials, first preheat at 600℃ for 20 minutes, then melt at 1520℃;

[0066] Step 4: Casting electrode rods. Casting conditions: Mold preheating: Preheat graphite mold to 600℃ to reduce thermal stress; Casting temperature: 1550±5℃; Speed: Inclined casting (30° angle), flow rate 2-3 kg / s; Cooling parameters: Argon protection cooling to 800℃, cooling rate 50℃ / s, followed by air cooling to room temperature. Final electrode specifications: Φ80×500mm, surface turned (Ra≤3.2μm).

[0067] The microstructure of the alloy rod prepared in this embodiment is as follows: Figure 1The grain size was assessed as approximately grade 9 according to ASTM E112, "Standard Test Method for Determination of Average Grain Size". The grains are very fine. The measured corrosion resistance is shown in Table 1.

[0068] Example 2

[0069] Prepare acid and alkali resistant alloy materials according to the following steps:

[0070] Step 1: 21wt%Cr, 6.5wt%Mo, 18.5wt%Ni, 1.1wt%Cu, 0.08wt%Ce, ≤0.02wt%C and 52.8wt%Fe are loaded into the furnace. The loading order is as follows: first load the refractory metals (Mo, Fe), then load the fusible metals (Ni, Cu, Cr). Ce is wrapped in foil and added last. All raw materials need to be sandblasted and ultrasonically cleaned with alcohol for 10 minutes, and then dried at 80℃ for 2 hours.

[0071] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 The operating procedure is as follows: 1. Pre-pump with a mechanical pump to ≤10 Pa; 2. Switch to a diffusion pump, heat to the operating temperature, and then pump to ≤5×10 Pa. -3 3. Pressure holding test: Leakage rate ≤ 0.02 Pa / min;

[0072] Step 3: Heat to melt the raw materials, first preheat at 600℃ for 20 minutes, then melt at 1510℃;

[0073] Step 4: Casting the electrode rod. Casting conditions: Mold preheating: Preheat the graphite mold to 600℃ to reduce thermal stress; Casting temperature: 1550±5℃; Speed: Inclined casting (30° angle), flow rate 2-3 kg / s; Cooling parameters: Argon protection cooling to 800℃, cooling rate 50℃ / s, followed by air cooling to room temperature. The final electrode specifications are: Φ80×500mm, surface turned (Ra≤3.2μm).

[0074] Step 5: After machining and surface treatment of the obtained electrode rod, passivation treatment is performed. The passivation solution consists of 10% citric acid + 10% hydrogen peroxide + 0.05% cerium chloride + 1% sodium molybdate. The passivation process involves first maintaining the solution at 60°C for 30 minutes to form a film, then maintaining the solution at 40°C for 20 minutes to solidify the hydrophobic layer. After passivation, the layer is neutralized, rinsed with water, and then dried under nitrogen protection at 80°C. Preferably, 0.1 wt% sodium citrate, a pH stabilizer, can also be added to the passivation solution.

[0075] The microstructure of the alloy rod prepared in this embodiment is as follows: Figure 2The grain size was evaluated according to ASTM E112, "Standard Test Method for Determination of Average Grain Size", and was approximately grade 9-10. The grains were uniform, and the measured corrosion resistance is shown in Table 1.

[0076] Example 3

[0077] The following method and steps are used to prepare an alloy material for ball screw support bearings that is resistant to acid and alkali corrosion.

[0078] Step 1: 18.3wt%Cr, 6.5wt%Mo, 17.5wt%Ni, 1wt%Cu, 0.05wt%Ce, ≤0.02wt%C and 52.7wt%Fe are loaded into the furnace. The loading order is as follows: first load the refractory metals (Mo, Fe), then load the fusible metals (Ni, Cu, Cr). Ce is wrapped in foil and added last. All raw materials need to be sandblasted and ultrasonically cleaned with alcohol for 10 minutes, and then dried at 80℃ for 2 hours.

[0079] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 The operating procedure is as follows: 1. Pre-pump with a mechanical pump to ≤10 Pa; 2. Switch to a diffusion pump, heat to the operating temperature, and then pump to ≤5×10 Pa. -3 3. Pressure holding test: Leakage rate ≤ 0.02 Pa / min;

[0080] Step 3: Heat to melt the raw materials, first preheat at 600℃ for 20 minutes, then melt at 1520℃;

[0081] Step 4: Add 2.8 wt% FeCrN, stir for 12-15 minutes, maintain the furnace temperature at 1550±10℃, use a nitrogen-argon mixed gas (90% Ar + 10% N2) for environmental control, and blow argon from the bottom to stir the melt and promote FeCrN melting. Maintain a slight positive pressure of 0.1 MPa in the furnace to avoid nitrogen loss. Preferably, FeCrN-6.5 is used, and it can be added in two batches. The first batch contains 60% of the total amount, and the remaining FeCrN is added after an interval of 2-3 minutes to ensure uniform melting.

[0082] Step 5: Casting electrode rods. Casting conditions: Mold preheating: Preheat graphite mold to 600℃ to reduce thermal stress; Casting temperature: 1550±5℃; Speed: Inclined casting (30° angle), flow rate 2-3 kg / s; Cooling parameters: Argon protection cooling to 800℃, cooling rate 50℃ / min, followed by air cooling to room temperature. Final electrode specifications: Φ80×500mm, surface turned (Ra≤3.2μm).

[0083] The grain size of the alloy rod prepared in this embodiment was evaluated as approximately grade 9-10 according to ASTM E112, "Standard Test Method for Determination of Average Grain Size". The grains are very fine and uniformly distributed. The measured corrosion resistance is shown in Table 1.

[0084] Example 4

[0085] The following method and steps are used to prepare alloy materials for ball screw support bearings that are resistant to acid and alkali corrosion:

[0086] Step 1: 18.7wt% Cr, 6.5wt% Mo, 18.5wt% Ni, 1.1wt% Cu, 0.08wt% Ce, ≤0.02wt% C and 51.7wt% Fe are loaded into the furnace. The loading order is as follows: first load the refractory metals (Mo, Fe), then load the fusible metals (Ni, Cu, Cr). Ce is wrapped in foil and added last. All raw materials need to be sandblasted and ultrasonically cleaned with alcohol for 10 minutes, and then dried at 80℃ for 2 hours.

[0087] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 pa, evacuate the furnace to a vacuum state, pressure value ≤5×10 -3 The procedure for Pa is as follows: 1. Pre-pump with a mechanical pump to ≤10 Pa; 2. Switch to a diffusion pump, heat to the operating temperature, and then pump to ≤5×10 Pa. -3 3. Pressure holding test: Leakage rate ≤ 0.02 Pa / min;

[0088] Step 3: Heat to melt the raw materials, first preheat at 600℃ for 20 minutes, then melt at 1510℃;

[0089] Step 4: Add 3.4wt% FeCrN, stir for 12-15 minutes, maintain the furnace temperature at 1550±10℃, use a nitrogen-argon mixed gas (90%Ar+10%N2) for environmental control, and blow argon from the bottom to stir the melt and promote FeCrN melting. Maintain a slight positive pressure of 0.1MPa in the furnace to avoid nitrogen loss. Preferably, FeCrN-6.5 is used, and it can be added in two batches. The first batch contains 60% of the total amount, and the remaining FeCrN is added after an interval of 2-3 minutes to ensure uniform melting.

[0090] Step 5: Casting the electrode rod. Casting conditions: Mold preheating: Preheat the graphite mold to 600℃ to reduce thermal stress; Casting temperature: 1550±5℃; Speed: Inclined casting (30° angle), flow rate 2-3 kg / s; Cooling parameters: Argon protection cooling to 800℃, cooling rate 50℃ / min, followed by air cooling to room temperature. The final electrode specifications are: Φ80×500mm, surface turned (Ra≤3.2μm).

[0091] Step 6: After machining and surface treatment of the obtained electrode rod, passivation treatment is performed. The passivation solution consists of 10% citric acid + 10% hydrogen peroxide + 0.05% cerium chloride + 1% sodium molybdate. The passivation process involves first maintaining the solution at 60°C for 30 minutes to form a film, then maintaining the solution at 40°C for 20 minutes to solidify the hydrophobic layer. After passivation, the layer is neutralized, rinsed with water, and then dried under nitrogen protection at 80°C. Preferably, 0.1 wt% sodium citrate, a pH stabilizer, can also be added to the passivation solution.

[0092] The grain size of the alloy rods prepared in this embodiment was assessed as approximately grade 9-10 according to ASTM E112, "Standard Test Method for Determination of Average Grain Size," indicating uniform grain size. Therefore, the alloy rods treated using the method in this embodiment have uniform grain size, meeting the standard requirements. Their measured corrosion resistance is shown in Table 1.

[0093] Example 5

[0094] The following method and steps are used to prepare an alloy material for ball screw support bearings that is resistant to acid and alkali corrosion.

[0095] Step 1: 19.2wt% Cr, 6.2wt% Mo, 18.5wt% Ni, 1.1wt% Cu, 0.1wt% Ce, ≤0.02wt% C and 52.73wt% Fe are loaded into the furnace. The loading order is as follows: first load the refractory metals (Mo, Fe), then load the fusible metals (Ni, Cu, Cr). Ce is wrapped in foil and added last. All raw materials need to be sandblasted and ultrasonically cleaned with alcohol for 10 minutes, and then dried at 80℃ for 2 hours.

[0096] Step 2: Evacuate the furnace to a vacuum state, with a pressure value ≤ 5 × 10⁻⁶. -3 The operating procedure is as follows: 1. Pre-pump with a mechanical pump to ≤10Pa; 2. Switch to a diffusion pump, heat to the operating temperature, and then pump to ≤5×10 Pa. -3 3. Pressure holding test: Leakage rate ≤ 0.02 Pa / min;

[0097] Step 3: Heat to melt the raw materials, first preheat at 600℃ for 20 minutes, then melt at 1520℃;

[0098] Step 4: Add 3.0 wt% FeCrN, stir for 12-15 minutes, maintain the furnace temperature at 1550±10℃, use a nitrogen-argon mixed gas (90% Ar + 10% N2) for environmental control, and blow argon from the bottom to stir the melt and promote FeCrN melting. Maintain a slight positive pressure of 0.1 MPa in the furnace to avoid nitrogen loss. Preferably, FeCrN-6.5 is used, and it can be added in two batches. The first batch contains 60% of the total amount, and the remaining FeCrN is added after an interval of 2-3 minutes to ensure uniform melting.

[0099] Step 5: Casting the electrode rod. Casting conditions: Mold preheating: Preheat the graphite mold to 600℃ to reduce thermal stress; Casting temperature: 1550±5℃; Speed: Inclined casting (30° angle), flow rate 2-3 kg / s; Cooling parameters: Argon-protected cooling to 800℃, cooling rate 50℃ / s; 800℃-400℃, cooling rate 20℃ / s; below 400℃, air cooling; Final electrode specifications: Φ80×500mm, surface turned (Ra≤3.2μm).

[0100] Step 6: After machining and surface treatment of the obtained electrode rod, passivation treatment is performed. The passivation solution consists of 10% citric acid + 10% hydrogen peroxide + 0.05% cerium chloride + 1% sodium molybdate. The passivation process involves first maintaining the solution at 60°C for 30 minutes to form a film, then maintaining the solution at 40°C for 20 minutes to solidify the hydrophobic layer. After passivation, the electrode rod is neutralized, rinsed with water, and then dried under nitrogen protection at 80°C. Preferably, 0.1% sodium citrate, a pH stabilizer, can also be added to the passivation solution.

[0101] Step 7: Sealing treatment, immerse in 0.05% Ce(NO3)3 melt at 80℃ for 20-30 minutes to form Ce-O modified passivation film.

[0102] The alloy prepared in this embodiment has a grain size of approximately 9-10 according to ASTM E112, "Standard Test Method for Determination of Average Grain Size," indicating uniform grain size. Therefore, the alloy bars treated using this method have uniform grain size, meeting the standard requirements. The alloys obtained in Examples 1-5 were subjected to acid and alkali resistance cycling tests, the test procedure as follows: Figure 4 As shown in Table 1, the test results are as follows:

[0103] Table 1. Results of acid and alkali resistance cycling tests on alloys prepared in Examples 1-5.

[0104]

[0105] Corrosion rate in Table 1 = Where K is the unit conversion constant, which is equal to 8.76 × 10⁻⁶. 4 , The loss is weight (g), ρ is the material density, A is the exposed area (Φ80×500mm), and T is the test time. In this application, the cycle is 500 times, and the test time is calculated as 1 year. The average annual corrosion rates of the alloy products prepared in Examples 1-5 of this invention are 0.45µm / year, 0.43µm / year, 0.26µm / year, 0.19µm / year, and 0.10µm / year, respectively. Compared with the SEMI7 standard, the bearing products prepared in Examples 1-5 can all meet the general requirement of <0.5µm / year for semiconductor equipment. The corrosion resistance of Examples 3-5 is even better.

[0106] Furthermore, the stability of the surface passivation films in Examples 4 and 5 was analyzed and tested. Standardized EIS experiments combined with equivalent circuit fitting were used to test the charge transfer resistance (Rc). t The test results for the dispersion coefficient (n) and the diffusion coefficient (n) are shown in Table 2.

[0107] Table 2. Performance of passivation films obtained in Examples 4 and 5

[0108]

[0109] As shown in Table 2, the passivation films of the products prepared in Examples 4 and 5 are relatively complete and uniform.

[0110] The alloy obtained in Example 5 was used to manufacture ball screw support bearings. The applicant found that this alloy material is suitable for manufacturing the outer ring, inner ring, and rolling elements of ball screw support bearings, which can significantly improve the reliability and lifespan of ball screw support bearings under harsh operating conditions. The product, such as... Figure 5 As shown.

Claims

1. A method for producing an alloy material resistant to acid and alkali corrosion, characterized by comprising the steps of: Comprising the following steps: ​ Step 1: charging 18.3-19.2wt%Cr, 6.0-6.5wt%Mo, 17.5-18.5wt%Ni, 0.8-1.2wt%Cu, 0.05-0.1wt%Ce, ≤0.02wt%C and 51.5-54.2wt%Fe into the furnace; Step 2: The furnace is evacuated to a vacuum state, pressure value < 5 x 10 -3 Pa; Step 3: heating to melt the raw materials, preheating at 600℃ for 20 minutes, and then melting at 1520±10℃; Step 4: adding 2.8-3.4wt%FeCrN, stirring for 12-15 minutes, maintaining the temperature in the furnace at 1550±10℃, using nitrogen-argon mixed gas protection, and maintaining a slight positive pressure; Step 5: casting the electrode rod; Step 6: after machining and surface treatment of the prepared electrode rod, passivation treatment is performed, the passivation solution is 10% citric acid + 10% hydrogen peroxide + 0.05% cerium chloride + 1% sodium molybdate, specifically: the passivation solution with water as the solvent, the mass fraction of citric acid is 10%, the mass fraction of hydrogen peroxide is 10%, the mass fraction of cerium chloride is 0.05%, and the mass fraction of sodium molybdate is 1%; the passivation process: first film formation at 60℃ for 30 minutes, and then maintaining at 40℃ for 20 minutes, after passivation, neutralization and water washing are performed, and then drying is performed under the protection of nitrogen gas at 80℃, the grain grade of the acid and alkali corrosion resistant alloy material is 9-10, which is composed of 20.5-21.0wt%Cr, 6.0-6.5wt%Mo, 17.5-18.5wt%Ni, 0.18-0.22wt%N, 0.8-1.2wt%Cu, 0.05-0.1wt% Ce, ≤0.02wt%C and the balance of Fe and unavoidable impurities, wherein the content of Mo+Cu is ≥7wt%, the mass ratio of Cr / Ni is 1.1-1.2, the alloy material surface contains a passivation layer, the passivation layer has a three-layer structure, the outermost layer is a surface organic layer which is a citric acid-Cr complex and plays a hydrophobic barrier role; the intermediate transition layer is CrOOH+Fe2O3+Ni(OH)2, which plays a role in buffering stress and inhibiting interface peeling; the doped oxide layer is Cr2O3+ MoO2+ CeO2, which is the main corrosion protection layer and blocks ion penetration.

2. The method of claim 1, wherein the alloy material is prepared by the steps of: preparing a molten alloy by melting a plurality of alloying elements; and casting the molten alloy. Further comprising step 7: sealing treatment, soaking in 0.05% Ce(NO3)3 solution at 80℃ for 20-30 minutes.

3. An alloy material resistant to acid and alkali corrosion, characterized by comprising: Prepared by the method of claim 1 or 2.

4. The alloy material resistant to acid and alkali corrosion according to claim 3, characterized in that, The pitting corrosion equivalent of the alloy material is 43.18-45.

97.

5. An article prepared from the acid and alkali corrosion resistant alloy material of claim 3, which is a ball screw support bearing.

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