What is Pickled and Oiled Steel?
Pickling
Purpose: To remove the iron oxide scale (Fe₂O₃, Fe₃O₄) on the surface of hot-rolled or cold-rolled steel strips and improve the surface finish.
Method: Soak in hydrochloric acid (HCl) or sulfuric acid (H₂SO₄), then wash, neutralize and dry.
Effect: The surface is silvery white, without oxide scale, suitable for subsequent stamping, electroplating or painting.
Oiling
Purpose: To prevent steel from rusting during transportation and storage.
Oil type:
Ordinary anti-rust oil (short-term anti-rust, 3~6 months).
Anti-fingerprint oil (commonly used in the home appliance industry, no fingerprints left when touched).
Amount of oil: Usually 0.5~3 g/m² (adjustable according to needs)
Common grades and standards of Pickled and Oiled Steel
|
Brand |
standard |
Features |
Main Application |
|
SAE1006 |
American Standard (SAE J403) |
Low carbon, high formability |
Automotive stamping parts, hardware |
|
SPHC |
Japanese Standard (JIS G3131) |
Equivalent to SAE1006 |
Home appliances, chassis |
|
DC01 |
European Standard (EN 10130) |
Ultra-low carbon, higher elongation |
Deep stamping parts, complex forming |
|
Q195 |
National Standard (GB/T 700) |
Slightly higher carbon content, slightly higher strength |
Structural parts, welded pipes |
The Differences Between Pickled and Oiled Steel and Galvanized Steel and Cold Rolled Steel
|
Comparison items |
Pickled and oiled steel |
Galvanized steel |
Cold rolled steel (not pickled) |
|
Surface treatment |
Pickled + oiled |
Galvanized layer |
Untreated (may have scale) |
|
Rust resistance |
Short-term rust prevention (several months) |
Long-term rust prevention (several years) |
Rust-prone |
|
Processing performance |
Excellent (suitable for stamping) |
Good (zinc layer may affect welding) |
Normal (scaling required) |
|
Cost |
Lower |
High |
Minimum |
Can Pickled and Oiled Steel be welded?
Can be welded, pickled and oiled steel (such as SAE1006, SPHC, etc.) has good welding performance, but because the surface is coated with anti-rust oil, it needs to be properly treated before welding to avoid pores, cracks or smoke problems.
Processing steps before welding
(1) Remove the surface anti-rust oil
Method:
Solvent cleaning: Wipe the welding area with acetone, alcohol or special degreaser.
Mechanical grinding: Use sandpaper or wire brush to clean the area near the weld (about 20~30mm wide).
Purpose: To prevent oil stains from burning at high temperatures to produce pores or smoke.
(2) Check the surface oxidation
If the pickling is stored for a long time, slight rust may occur, which needs to be removed with sandpaper.
