What is the surface treatment of stainless steel strip
source:
www.p-t7.com | Release time:2025年12月15日
The surface treatment of stainless steel strip is a key process to improve its corrosion resistance, aesthetics, and processing adaptability, and the corresponding treatment process needs to be selected according to downstream application scenarios (such as home appliances, electronics, precision machinery). The following are common surface treatment methods, process characteristics, and applicable scenarios for stainless steel strips:
1、 Basic treatment process (removing surface defects and laying the foundation for subsequent processing)
1. Acid pickling and passivation
Process principle: Immerse the stainless steel strip in a mixed acid solution of sulfuric acid, nitric acid, and hydrofluoric acid to dissolve the oxide scale, rust spots, and oil stains generated during the hot/cold rolling process; After acid washing, passivation treatment is carried out to form a dense chromium passivation film on the surface.
Process features: Remove surface impurities and enhance corrosion resistance; After treatment, the surface appears matte gray white (i.e. 2D surface) with no reflectivity.
Applicable scenarios: Basic pretreatment of all stainless steel strips, especially suitable for substrates that require further polishing or spraying in the future.
2. Deburring and leveling
Process principle: For the stainless steel strip after longitudinal cutting and slitting, edge burrs and slight scratches on the surface are removed by sanding, electrolytic polishing, and rolling leveling, and the warping and wavy edges of the strip are corrected.
Process features: Improve edge smoothness (roughness Ra ≤ 0.8 μ m), ensure strip flatness, and avoid scratching the mold or product during subsequent stamping.
Applicable scenarios: Stainless steel strips for precision electronic components and stamping parts.
2、 Mainstream surface finishing techniques (enhancing aesthetics and functionality)
1.2B surface treatment (cold rolling, annealing, acid washing)
Process principle: After annealing, cold-rolled stainless steel strip is subjected to acid washing and slight roll polishing to form a uniform matte surface.
Process characteristics: Medium surface finish (Ra 0.2-0.8 μ m), excellent corrosion resistance, good processing performance (can be stamped and bent), and moderate cost.
Applicable scenarios: Components such as household appliance liners (refrigerators, washing machines), kitchenware, medical equipment, etc. that require hygiene and corrosion resistance.
2. BA surface treatment (bright annealing)
Process principle: Cold rolled stainless steel strip is annealed in a high-purity nitrogen or hydrogen protective atmosphere, without acid washing, and is directly leveled slightly by a rolling mill.
Process features: The surface has a mirror effect (Ra ≤ 0.1 μ m), high reflectivity, delicate texture, and can meet decorative requirements without additional polishing.
Applicable scenarios: Home appliance panels, electronic display screen borders, decorative parts, and other products that require high appearance.
3. Brushing treatment (hairline treatment)
Process principle: Through unidirectional grinding with sand belts and nylon wheels, a uniform straight texture (divided into straight and irregular patterns) is formed on the surface of the stainless steel strip.
Process features: Good anti fingerprint effect, delicate touch, covering slight scratches on the surface; Texture thickness can be adjusted according to needs (such as No.3 coarse drawing, No.4 fine drawing).
Applicable scenarios: Decorative components such as home appliance casings (range hoods, gas stoves), elevator panels, hardware accessories, etc.
4. Mirror polishing
Process principle: Multi stage polishing (coarse polishing → medium polishing → fine polishing) is adopted, and the surface is polished with a grinding wheel, polishing paste, and wool wheel in sequence until the mirror reflection effect is achieved.
Process features: Surface roughness Ra ≤ 0.01 μ m, reflectivity ≥ 90%, highly decorative; But the cost is high and it is prone to scratches.
Applicable scenarios: bathroom products, optical instrument components, decorative stainless steel strips.
3、 Functional surface treatment process (strengthening special properties)
1. Electroplating treatment
Common types: galvanized, chrome plated, nickel plated.
Process principle: By electrolysis, a layer of metal coating is deposited on the surface of stainless steel strip.
Process features: Galvanizing enhances rust resistance; Chrome plating enhances wear resistance and decorative properties; Nickel plating improves conductivity and corrosion resistance.
Applicable scenarios: Conductive spring plates for electronic components and wear-resistant layers for hardware.
2. Spray treatment
Common types: powder coating, spray painting, vacuum coating.
Process principle: Spray organic coating or vacuum deposit metal film (such as titanium gold, rose gold) on the surface of stainless steel strip.
Process features: It can achieve diversified colors and enhance decoration; The coating has scratch resistance and anti fingerprint properties.
Applicable scenarios: Home appliance exterior panels, stainless steel strips for building decoration.
3. Anti fingerprint processing
Process principle: Apply a nano scale anti fingerprint coating on the surface of stainless steel strip to form a hydrophobic and oil repellent protective film.
Process features: The surface is not easily stained with fingerprints or oil stains, and is easy to clean; Not affecting the original glossiness, while improving corrosion resistance.
Applicable scenarios: high-frequency contact components such as home appliance panels, mobile phone casings, elevator handrails, etc.
4. Electrolytic polishing
Process principle: Using stainless steel strip as the anode, immerse it in electrolyte and apply electricity to dissolve the surface protrusions through electrochemical action, making the surface smooth and even.
Process features: Low surface roughness, better corrosion resistance than mechanical polishing; No stress damage, suitable for ultra-thin stainless steel strips.
Applicable scenarios: Stainless steel strips for precision electronic components and medical devices.