Manufacturing Process

Pickling & Coating Process

Not only does Woosin Steel have a pickling & coating facility with maximum energy efficiency, but it also runs the Dual Process utilizing both sulfuric and hydrochloric acids, thus meeting the various needs of our clients and guaranteeing differentiated coating quality.

Preheating water tank - Hydrochloric acid bath - Sulfuric acid tank - Shower tray - Non-phosphate coating - Coating bath - Rinse tank - Neutralization tank - Lubricant bath - SMART coating - Lime bath

1st Pickling & Coating (CA, BCA): Calcic coating removes scale from raw materials and prevents corrosion.

2nd Pickling & Coating (BRL, SMART, NoP): This coating removes scale from materials and prevents burning during the Cold Heading process

Surface Treatment Technology

- Bonderizing Coating (BRL: Bonderite + Lube)

This is a CHQ coating process in which phosphate is formed on the surface of metal through a chemical reaction, thereby increasing thermal stability and lubricant retention capacity.

- SMART Coating (SMART : BR + Polymer Coating)

This is an environmentally-friendly CHQ coating process that offers improved processability and lower manufacturing costs by combining a polymer method with the existing Bonderizing Coating process.

- Non-bonderizing Coating (NoP : Non-Phosphate Coating)

This is a CHQ coating process in which brittle fractures caused by phosphorizing during after-treatment is prevented by a mineral coating substance from which phosphorus has been removed.


The clients’ thickness and mechanical property requirements are met by the process of letting the pickled & coated material go through the dies. Woosin Steel operates the only drawing facility in Korea capable of manufacturing 55mm products under an automatic control system.

1st Drawing(WD): Spheroidization during heat treatment promoted through the segmentation of pearlite tissue by cold wire drawing, thus improving diametrical variations of the material

2nd Drawing(SKP): The clients’ needs are met by precision drawing.

Spheroidized Annealing

The cold plasticity of pearlite tissue in the raw material is maximized by reducing solidity and improving ductility through spheroidization annealing.

Typical Process

HD W/R – PC – SKP – PK
(S)AIP W/R – P – SA – PC – SKP – PK
RAIP W/R – P – WD – RA – PC – SKP – PK
SAIP W/R – P – WD – SA – PC – SKP – PK
PASAIP W/R – P – LA – P – WD – SA – PC – SKP – PK
PSASAIP W/R – P – SA – P – WD – SA – PC – SKP – PK
SAPC W/R – P – SA – PC – PK

W/R (Wire Rod)

P (Pickling)

PC (Pickling&Coating)

WD (Wire Drawing)

SKP (Skin Pass)

LA (Low Temperature Annealing)

RA (Regular Annealing)

SA (Spheroidized Annealing)

PK (Packing)