In industrial piping systems and mechanical equipment sealing applications, plugs serve as critical sealing components. Their material strength and corrosion resistance directly impact the overall safety and stable operation of equipment. As a professional factory specializing in the R&D and production of plugs, we at Aohong always prioritize quality. We mainly select high-quality raw materials such as #35, #45 carbon steel, 304 stainless steel, and 316 stainless steel as our base materials.
Using #35 and #45 carbon steel as the base material, combined with three high-efficiency surface treatments: galvanizing, zinc-nickel alloy plating, and black oxide finish, we provide customers of Aohong Hydraulics with reliable and adaptable plug solutions.
1. Blue-White Zinc Plating: Cost-Effective Basic Anti-Corrosion Solution
For general industrial environments, municipal pipelines, and common mechanical equipment with moderate anti-corrosion requirements, our factory adopts electro-galvanizing (blue-white zinc) to form a uniform zinc layer of 8-15μm on the surface of #35 or #45 carbon steel plugs. This zinc layer physically isolates the carbon steel substrate from corrosive media such as air, moisture, and dust. If scratches or damage occur on the surface, the zinc layer oxidizes preferentially to protect the substrate from corrosion, significantly extending the service life of the plug to 5-8 years. Galvanized plugs feature a uniform silver-gray appearance, combining practicality and aesthetics with controllable production costs, making them a cost-effective choice for SMEs.
2. Zinc-Nickel Alloy Plating: High-End Protection for Harsh Environments
For highly corrosive environments such as marine applications, chemical workshops, and acid-alkali pipelines, our factory offers zinc-nickel alloy plating. Using advanced electroplating technology, a 5-10μm thick zinc-nickel alloy layer (nickel content 10%-15%) is deposited on #35 carbon steel plugs. Compared with traditional galvanizing, zinc-nickel alloy plating achieves a qualitative leap in corrosion resistance with a denser coating structure that effectively blocks penetration by chloride, sulfate, and other corrosive ions. This advantage is verified by the neutral salt spray test (GB/T 10125-2021): our zinc-nickel alloy plugs can withstand over 1000 hours of salt spray exposure (5% NaCl solution, 35°C, 95% RH) without red rust or coating detachment, only minor white rust appears – far exceeding the 200-300 hour standard for ordinary galvanized plugs. Additionally, the zinc-nickel alloy layer offers excellent wear resistance (HV300+) and adhesion (cross-cut test grade 0), maintaining stable protection in high-vibration, high-friction applications such as marine engines, new energy battery cooling systems, and medical device pipelines. Compliant with RoHS environmental standards, it is the preferred choice for high-end manufacturing customers.
3. Black Oxide Finish: Low-Cost Basic Protection Solution
For applications with low appearance requirements and simple anti-corrosion needs, such as internal pipelines of standard machinery, we provide black oxide finish. Through chemical oxidation, a black protective film is formed on the surface of #35 carbon steel plugs. Although corrosion resistance is lower than galvanizing and zinc-nickel alloy plating, it offers low cost and high processing efficiency, meeting basic sealing requirements for budget-sensitive projects. These three surface treatments – zinc-nickel alloy plating, blue-white zinc plating, and black oxide finish – form a comprehensive product portfolio covering high, medium, and low-grade applications. Strict quality control is implemented throughout the process: real-time monitoring of electroplating current, oxidation temperature, and other key parameters ensures uniform coating thickness and quality. In the final inspection, random samples from each batch undergo salt spray testing, adhesion testing (cross-cut method), and dimensional accuracy verification via projector. Non-conforming products are rejected, ensuring "premium quality at delivery."
Choosing Aohong means not only recognizing the material advantages of #35 carbon steel but also trusting our meticulous control over every production detail.
