Acier décapé et huilé: Le guide des produits, Processus & Applications

Si vous travaillez dans le secteur manufacturier, construction, ou ingénierie automobile, acier décapé et huilé (Acier PO) change la donne pour les projets nécessitant du nettoyage, résistant à la rouille, et métal facile à traiter. Contrairement à l'acier brut laminé à chaud, L'acier PO a une surface lisse, surface sans tartre, ce qui la rend idéale pour l'estampage, soudage, ou peinture. Ce guide détaille tout ce que vous devez savoir pour choisir, utiliser, and source PO steel effectively.

1. Pickled & Oiled Steel Products: Forms for Every Project

PO steel comes in versatile shapes tailored to different industrial needs. Knowing which product to pick saves time and reduces waste. Voici une ventilation:

Real Example: A tractor manufacturer usespickled and oiled steel sheet for its machine bodies. The smooth surface accepts paint evenly, and the oil coating prevents rust during storage—cutting rework costs by 15%.

2. Pickling & Oil-Coating Process: How PO Steel Is Made

The PO steel process transforms rough hot-rolled steel into a high-quality material in 5 key steps. Each stage ensures a clean, flat, and protected surface:

1. Hot-Rolled Steel Preparation: Start with hot-rolled steel (from a blast furnace), which has a thick, flaky oxide layer (“scale”) on its surface.
2. Acid Pickling Line: The steel is dipped in a bath of either acide chlorhydrique ou acide sulfurique (30–40% concentration) at 60–80°C. This dissolves the scale—hydrochloric acid works faster (10–15 minutes vs. 20–25 for sulfuric) and leaves a smoother surface.
3. Rinsing & Séchage: After pickling, the steel is rinsed with water to remove acid residue (prevents pitting) and dried with hot air.
4. Tension Leveling: The steel passes through rollers under tension to fix warping. Cette étape garantit improved flatness—critical for stamping or welding.
5. Oil Coating: Une fine couche de rust preventive oil (par ex., mineral oil or eco-friendly ECO oil) is applied via spraying or rolling. The oil creates a barrier against moisture, keeping the steel rust-free for 3–6 months in storage.
6. Edge Trimming (Facultatif): For sheets or strips, edges are trimmed to remove irregularities and ensure consistent width.

Pro Tip: Hydrochloric acid is better for automotive-grade PO steel (needs ultra-smooth surfaces), while sulfuric acid is more cost-effective for construction parts.

3. Qualité des surfaces & Propriétés: Why PO Steel Outperforms Hot-Rolled

PO steel’s unique properties solve common problems with hot-rolled steel (like scale or rust). Here are its most valuable traits:

• Scale-Free Surface: Pickling removes all oxide scale, so there’s no need for grinding or sandblasting before painting/welding. This saves 20–30% on prep time.
• Improved Flatness: Tension leveling eliminates warping—PO steel sheets lie flat, making assembly easier (par ex., for storage tanks).
• Uniform Oil Film Thickness: The oil coating is 5–10 μm thick (consistent across the surface), so no area is unprotected from rust.
• Enhanced Paint Adhesion: The clean, slightly porous surface (from pickling) lets paint bond better. Tests show paint on PO steel lasts 2x longer than on untreated hot-rolled steel.
• Reduced Oxide Pitting: Acid pickling removes deep scale, preventing pitting that can weaken parts (critical for pressure vessels).

Data Comparison: PO Steel vs. Untreated Hot-Rolled Steel

4. Applications & End-Use Industries: Where PO Steel Shines

PO steel’s versatility makes it a staple in industries needing clean, easy-to-work metal. Here are its top uses:

• Automobile: Composants de châssis automobile (Acier PO) (par ex., frame rails, control arms) rely on its flatness for precise welding and its scale-free surface for corrosion-resistant coatings.
• Pipe & Tube: Pipe and tube manufacturing (Acier PO) uses coils—its smooth surface ensures seamless welding, and the oil coating prevents rust during tube forming.
• Agricole: Tractor bodies, plow blades, and harvester parts use PO steel sheets—its durability resists dirt and impact, and the oil coating protects it during outdoor storage.
• Estampillage: Stamping and deep drawing (Acier PO) is ideal for complex shapes (par ex., metal buckets, supports automobiles)—its ductility and smooth surface prevent cracking during forming.
• Stockage & Pressure Vessels: Storage tanks and pressure vessels (Acier PO) need a scale-free surface to avoid weak points—pickling ensures the steel can handle high pressure without leaking.

5. Notes, Normes & Caractéristiques: Ensuring Quality

Using certified PO steel avoids defects and ensures compliance with industry rules. Here are the key standards and grades to know:

Certification Tip: Always request a Mill Test Report (MTR) to confirm the steel meets your grade—this document verifies pickling process, oil type, et qualité de surface.

6. Revêtements & Post-Treatments: Extending PO Steel’s Lifespan

PO steel can be further treated to boost rust resistance, improve paint adhesion, or fit specific project needs. Here are the most common options:

• Oiled vs. Dry Pickled Steel: Oiled PO steel has rust protection for storage; dry pickled steel (no oil) is better for projects where oil could contaminate processes (par ex., food-grade tanks).
• Pre-Primed Pickled and Oiled Steel: A factory-applied primer is added to the oiled surface—saves time on-site, as the steel is ready to paint.
• Thin Organic Coating: A polymer layer (par ex., époxy) is applied over the oil—ideal for outdoor parts (par ex., construction framing) that need long-term rust resistance.
• Rust-Preventive Oil Types: Mineral oil is cost-effective for indoor storage; ECO oil is biodegradable (better for environmentally sensitive projects, like marine equipment).
• Wax-Coated Pickled and Oiled Steel: A thick wax layer provides 12+ months of rust protection—used for long-term storage or shipping to humid regions.

Yigu Technology’s Perspective

Chez Yigu Technologie, nous recommandonsacier décapé et huilé for clients needing efficient, low-waste manufacturing. For automotive projects, we supply SAE 1008/1010 PO steel—its ductility ensures smooth stamping, and our hydrochloric pickling process delivers a paint-ready surface. For construction clients, we offer A36 PO steel with ECO oil, s'aligner sur les objectifs de développement durable. We also provide custom-slit coils to match project widths, reducing material waste by up to 10%.

FAQ

1. Do I need to remove the oil from PO steel before welding?
   Yes—oil can burn during welding, creating porous welds. Wipe the surface with a degreaser (par ex., acétone) before welding to ensure strong joints.
2. How long does the oil coating on PO steel last?
   Standard rust preventive oil lasts 3–6 months in indoor storage. For outdoor or humid conditions, choose wax-coated PO steel (12+ mois) or zinc-plate it for permanent protection.
3. Can PO steel be used for food-grade applications?
   Yes—but use dry pickled steel (no oil) and ensure it meets food-safe standards (par ex., ASTM A240 for stainless steel PO variants). The scale-free surface prevents bacteria buildup.