This article mainly introduces BA and EP stainless steel pipes. BA (Bright Annealing) and EP (Electrolytic Polishing) are two main surface treatment methods for stainless steel pipes, and their main differences lie in treatment processes, surface finish, corrosion resistance, and application scenarios.
1.Differences in process and Principle
BA(Bright Annealing): Bright surface effect is formed on the surface of stainless steel pipes through high-temperature annealing under argon atmosphere protection, with the surface showing a matte finish.
EP(Electropolishing): Microscopic protrusions on the surface are removed via anodic dissolution to achieve a mirror-like finish, which significantly enhances corrosion resistance and reduces roughness.
BA EP
2. Smoothness
The surface roughness of BA grade is usually ≤ 0.45 μm, showing a uniform matte finish. The Ra value of EP grade is ≤ 0.15μm, which is close to a mirror-like finish and more suitable for high-purity requirements.
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3. Corrosion Resistance
EP offers superior corrosion resistance compared to BA, as it removes surface defects and the oxide layer.
4. Application Scenarios
BA Tubes: Suitable for applications with moderate purity requirements, such as standard high-purity gas delivery systems and biopharmaceutical equipment.
EP Tubes: Used in extreme cleanliness environments, including the semiconductor industry, ultra-high-purity media delivery (e.g., electronic-grade chemicals), and sterile medical devices.
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