Cov nyhuv ntawm pickling thiab passivation thaum lub sij hawm prefabrication, vuam, kev sim, thiab kev kho cua sov yuav ua rau cov hlau oxide, vuam slag, roj, thiab lwm yam av los mus sau rau ntawm cov yeeb nkab (carbon steel yeeb nkab, carbon tooj liab yeeb nkab, stainless hlau yeeb nkab) , uas yuav txo cov corrosion kuj ntawm cov yeeb nkab steel. Ntau yam. Pickling yog ib txoj kev tshem tawm cov tshuaj xeb: dilute acid xeb tshem tawm tsuas yog tshem tawm cov hlau oxides ntawm cov kav dej stainless hlau nrog oxygen. Rau ferrous hlau, nws tsuas yog hais txog hlau oxide, uas chemically reacts nrog cov hlau oxides thiab dissolves lawv nyob rau hauv cov kua qaub kom ua tiav lub hom phiaj ntawm xeb tshem tawm. Ua ntej pickling thiab xeb tshem tawm, cov roj nyob rau ntawm phab ntsa ntawm cov yeeb nkab steel hlau yuav tsum tau muab tshem tawm ua ntej, vim tias muaj roj tiv thaiv cov kua dej los ntawm kev tiv thaiv phab ntsa ntawm cov yeeb nkab steel. Muaj feem cuam tshuam rau kev tshem tawm xeb. Cov kav dej tsis muaj roj (xws li cov kav hlau tsis muaj hlau rau oxygen) yuav tsum tau degreased ua ntej. Pickling yog hais txog kev siv cov kev daws teeb meem xws li sulfuric acid los ntxuav cov oxide txheej thiab plua plav ntawm cov khoom ua haujlwm. Phosphating yog ib txoj kev kho mob los ntxuav qhov chaw.