Pickled and Oiled Steel Plate

Pickling Plate, the full name of which is hot rolled pickled and oiled sheets and coils, is a type of steel product manufactured from premium hot rolled thin coils. The raw material runs through a complete pickling line to strip off surface mill scale, followed by edge trimming, finishing and other finishing procedures.

Compared with ordinary hot rolled steel, it boasts better surface condition, tighter dimensional tolerance and superior stamping performance. Meanwhile, hot rolled pickled & oiled (HRPO) plate comes at a much lower cost than cold rolled steel sheet. For this reason, it is recognized as an ideal cost-saving substitute that “replaces cold rolled steel with hot rolled material”.

Pickled and oiled steel plate has found extensive applications across automobile manufacturing, machinery production, home appliance fabrication, light industry and hardware sectors. PO steel plate holds particularly vital usage in the production of auto chassis parts, wheel hubs, compressor housings and other key components.

Steel Plate Acid Pickling Process

1.  Clean the surface of pickled and oiled steel plate to wipe off all oil stains, dirt and surface impurities.

2.  Soak the steel plates in hydrochloric acid or sulfuric acid solution. The acid liquid dissolves the iron oxide scale on the metal surface.

3.  Flush the pickled steel plates fully with running water to wash away residual acid solution completely.

4.  Put the cleaned steel plates into drying equipment for thorough baking, to avoid rust generation on damp surfaces.

5.  Coat uniform anti-rust oil on the dried steel plates, forming a protective layer to keep the metal surface from oxidation.

Comparison Between Pickled Steel Sheet and Cold Rolled Steel Sheet

Principle of Steel Pickling

Pickling relies on the chemical dissolving power of acids.

Common pickling agents include hydrochloric acid, sulfuric acid and nitric acid.

These acids trigger chemical reactions with oxides and contaminants covering the surface on pickled and oiled steel plate, dissolving such substances and stripping them off the steel base.

Reference of Pickled Steel Sheet Applications, Common Grades & Specifications

How to Pick Suitable Pickled and Oiled Steel Plate

You need to judge from four core dimensions as follows:

Performance standards: surface finish and dimensional tolerance

service conditions: indoor or outdoor installation, exposure to chemical corrosive substances

Cost budget: available fund limits and mass production demands

Fabrication processes: stamping, bending and welding capability of the steel

Real-case Reference 1

A manufacturer that makes standard industrial machinery

All equipment is placed indoors, with moderate standards for surface appearance, and the company operates on a tight budget. Hot rolled pickled steel sheet will be the ideal option. It can meet basic structural strength and exterior needs, while keeping overall material costs down.

Real-case Reference 2

A producer of outdoor communication cabinets

Its products stay exposed to open-air weather all year round, which calls for strong corrosion resistance and weather-proof capacity. Galvanized pickled steel sheet is required here to guarantee long service life and stable performance of finished goods.

Application Scenarios and Material Grade Selection Recommendations

Advantages of Pickled and Oiled Plate

Superior surface finish: The steel surface is smooth and free of mill scale, scratches or other surface defects after pickling treatment.

Excellent dimensional accuracy: It features even thickness with a tolerance of ±0.05mm and flat plate shape.

Great mechanical properties: Balanced strength and toughness support stamping and bending forming. It delivers stable welding performance with low risks of air holes and cracks during welding.

Outstanding workability: Pickled and oiled steel plate boasts better ductility than regular hot rolled steel. It fits deep drawing and complex forming processes, and extra rust removal steps can be eliminated to simplify production workflows.

High cost performance: It carries much lower material costs than cold rolled steel while offering comparable comprehensive performance.

FAQ

Q1: What is the difference between pickled and oiled steel plate and cold rolled steel sheet?

A1: PO (Pickled & Oiled) Steel Plate is based on hot rolled steel with pickling treatment, with lower cost. Cold rolled steel has ultra-smooth surface and thinner thickness down to 0.3 mm for high-precision parts. PO plate fits medium-precision structural pieces, while cold rolled sheet targets high-standard appearance components with strict tolerance demands.

Q2: Can PO steel plate be used for outdoor products directly?

A2: No. The anti-rust oil on surface only provides short-term temporary protection during storage and processing. For long-term outdoor exposure, you need subsequent surface treatments such as painting, galvanizing or powder coating to boost anti-corrosion capacity.

Q3: What thickness range can you offer for PO steel plate?

A3: Our standard thickness range covers 1.0mm to 6.0mm, customizable width from 800mm to 2000mm and length from 1000mm to 6000mm according to clients’ drawing demands.

Q4: How long can PO steel stay rust-free under normal storage?

A4: Stored in a dry indoor warehouse without humid air or chemical gas, the anti-rust oil can protect the steel surface for 3-6 months. Avoid open-air stacking to prevent premature oxidation.