Pickling Of Stainless Steel Means

Pipeline pickling is the process of conditioning a new gas pipeline before putting it into service.

Pickling of stainless steel means. Pickling is the process used to remove weld. A solution called pickle liquor which usually contains acid is used to remove the surface impurities it is commonly used to descale or clean steel in various steelmaking processes. Mixtures of nitric and hydrofluoric acids are usually used for pickling stainless steels. Pickling is the removal of any high temperature scale and the low chromium layer of the steel surface by a chemical treatment such as nitric or hydrofluoric acids.

What is stainless steel. Pickling is a metal surface treatment used to remove impurities such as stains inorganic contaminants rust or scale from ferrous metals copper precious metals and aluminum alloys. Where the steel has been heated by welding or other heat treatments to the point where a coloured oxide layer can be seen there is a chromium depleted layer on the surface of the steel. But pickling is a very imprecise process with many drawbacks including strict epa regulations around its use.

Before most cold rolling processes previously hot rolled steel goes through a pickling line to remove the scale from the surface and make it easier to work. Pickling is a very similar process to passivation. To restore the best corrosion resistant performance the damaged metal layer must be removed exposing a fully alloyed stainless steel surface. Actually pickling and passivation refers metal submerged in a bathing liquid that removes imperfections and rust from the surface of stainless steel.

In new gas lines it is common to experience odor fade in gas as the natural gas odorant reacts with rust and mill scale inside new steel pipes thereby producing less odorous compounds. Refer to other topic. Processes on fabricated stainless steel parts further descaling operations are not usually necessary. Stainless steel pickling definition astm a380 practice for cleaning descaling and passivation of stainless steel parts equipment and systems defines pickling as a chemical treatment using strong corrosive acids that remove metallic contamination welding and heat treatment scales.

Pickling is the removal of any high temperature scale and any adjacent low chromium layer of metal from the surface of stainless steel by chemical means. 2 2 pickling pickling is the removal of a thin layer of metal from the surface of the stainless steel. A metallic alloy i e metal made of multiple elements such as chromium nickel and molybdenum is generally considered to be stainless when its chromium content is greater than about 12 percent by weight some document mention it is about 10 5 chromium with the balance being iron higher alloyed stainless.