Eco pickled surface

Steel which has undergone the EPS process acquires a high degree of resistance to subsequent development of surface oxide (rust), so long as it does not come into direct contact with moisture.

This abrasive + water slurry mixture is fed into a rotating impeller which propels it at high velocity across the object to be cleaned (see Figure 3).

Inside the slurry blasting cell, jets of water cleanse the steel strip of both the abrasive particles and the dislodged mill scale.

The strip speed and, therefore, system output increases in rough proportion to the number of EPS slurry blasting cells used.

This also holds true for common sheet metal fabrication processes, such as laser cutting, plasma cutting, stamping, welding, bending, and roll forming – no meaningful difference between steel strip using the EPS process and steel strip using acid pickling.

Conventional acid-pickled steel strip is frequently coated with a thin film of oil to serve as a barrier to contact with oxygen so as to prevent rusting.

In addition to the free Cl, compounds known as "chloride salts" remain on the surface of acid pickled steel in trace amounts, even after rinsing.

To prevent oxidation of the iron in the acid pickled strip, a thin film of oil is applied to the surface to serve as a barrier between the free Cl, chloride salts and oxygen.

However, an additive is used in the EPS slurry blast carrier liquid to reduce the "smut" that would otherwise remain on the surface and dull the appearance of EPS-processed strip.

[1] The Eco Pickled Surface process was a finalist in the 2013 American Metal Market (AMM) Awards for Steel Excellence.