What is DACRO?
DACRO is the transliteration and abbreviation of DACROMET, also known as Dacrok or Dacrotizing. In China, it is named zinc-chromium coating. It is a new type of anti-corrosion coating with zinc powder, aluminum powder, chromic acid and deionized water as its main components. Originating in the United States in the 1950s, it forms a uniform and dense composite coating on metal surfaces through coating, baking and other processes. In neutral salt spray tests, ordinary Dacromet coatings can withstand over 1,000 hours, with premium products exceeding 2,000 hours.
Advantages of Dacromet
In addition to its excellent anti-rust properties, Dacromet offers multiple advantages suitable for industrial applications, which are key reasons for its widespread adoption:
1. Outstanding High and Low Temperature Resistance: Dacromet coatings maintain stable performance within a temperature range of -50°C to 300°C, without peeling or cracking due to drastic temperature changes. This characteristic makes it irreplaceable for components operating under high-temperature conditions such as engines and exhaust pipes.
2. Strong Corrosion and Chemical Resistance: Besides resisting salt spray corrosion, Dacromet coatings can also withstand erosion from weak acids, weak alkalis, grease and various chemicals, making them suitable for harsh working environments like marine, chemical and mining industries.
3. No Risk of Hydrogen Embrittlement: Traditional electroplating processes can easily cause hydrogen embrittlement in high-strength steel, leading to component fracture during use. In contrast, the Dacromet process is an electrolysis-free coating technology that does not produce hydrogen atoms, fundamentally avoiding hydrogen embrittlement risks. Therefore, it is especially suitable for critical load-bearing components such as high-strength bolts and springs.
4. Better Environmental Performance (Compared to Traditional Processes): Although early Dacromet coatings contained hexavalent chromium, which posed certain environmental pollution risks, chromium-free Dacromet products have now been developed with technological advancements. Compared to traditional electroplating and hot-dip galvanizing processes, Dacromet technology generates less wastewater and exhaust gas with lower treatment difficulty, better aligning with modern industrial environmental requirements.
5. Uniform Coating with Excellent Coverage: Dacromet coatings can uniformly cover metal component surfaces, including complex structural areas like threads and gaps, eliminating the "edge effect" common in electroplating processes and ensuring effective protection for every area.
Limitations
Dacromet technology also has some limitations:
Applications: Widely Used Across Multiple Industries
Dacromet applications are extensive, particularly in fields with stringent requirements for corrosion resistance and specific performance, such as automotive manufacturing, transportation facilities and power engineering.
The table below summarizes its main application fields by industry and specific use cases:
Conclusion: The "Reliable Choice" for Industrial Anti-Rust
From automotive parts to outdoor facilities, from daily necessities to major engineering projects, Dacromet technology is silently protecting metal products in our lives. Despite certain limitations, its excellent anti-corrosion performance makes it an important technology that cannot be ignored in the field of metal surface treatment.
Dacromet uses its "strength" to safeguard the safe operation of various metal components. With continuous breakthroughs in environmentally-friendly and high-performance technologies, Dacromet's application fields will further expand. If your industry is seeking efficient and reliable metal anti-rust solutions, take a closer look at Dacromet technology—it might just be the "reliable choice" you've been searching for.
Ningbo Qianhao Metal Products Co., Ltd. is a professional casting and machining manufacturer. Through stringent selection, we have established deep partnerships with multiple top-tier Dacromet suppliers in the industry. Whether you are a new partner or an old friend, we will provide you with quality products and services with 100% dedication!
Author：Ji Yanxiu, Head of Quality Control Department