PICKLING & PASSIVATING STAINLESS STEELS
Stainless steel pickling is the most common pickling process used at Metapic’s facility. The most common application for stainless steel pickling is to “ pickle / passivate ”. This is a one-step process which removes heat tint and weld scale while simultaneously passivating the surface of the parts being processed. Most customers are surprised to find out that pickling also accomplishes passivation. However, where required by our customers, Metapic will pickle and passivate in two complete and separate steps.
The importance of pickling, passivating and cleaning Stainless Steel cannot be stressed enough. These processes remove rusts, heat scales, weld contamination and can detect faults in the product. Furthermore, stainless steel can acquire surface contamination even in non-corrosive environments. Therefore, the possibility of corrosion is greatly reduced and the life of the treated stainless steel increased. Metapic procedures are generally in acordance with ASTM A380.
Significant Added Value
In relation to the material and labour costs incurred by stainless steel production, the relatively low additional cost of pickling is insignificant. Yet without this important proccess the integrity of the product is likely to be seriously deminished in the future.
PICKLING & PASSIVATING CARBON STEELS
Metapic offers carbon steel, cleaning, de-rusting and pickling in a dedicated carbon steel facility, as well as, and oiling and corrosion protection services. From carbon steel vessels to carbon steel piping, Metapic can provide pickling services to fit your needs. A typical carbon steel pickling job will consist of pre-cleaning, pickling and oiling. The pre-cleaning step is usually done with degreasers or hot caustic solutions.
Pickling solutions normally consist of Hydrochloric acid with an inhibitor and water. The final step in most pickling jobs is the application of a rust inhibitor. Carbon steel cleaning and pickling can also be used as a pre-treatment step prior to painting.
For hydraulic use the internal wall of the pipe can be coated with a number of oils. I.E. Esso Rust-Ban, Shell Ensis, Tectyl 506 etc.
If oil is not required the bore can be Nitrogen purged, or Silica Gel desiccant bags can be inserted into the bore. All ends and ports are then either capped, plugged or taped. Where requested external surfaces of pipe can be primed with a paint suitable to customers requirements.