Hebei ChongSheng Special Steel Pipe Co.,Ltd.

Stainless steel parts from corrosion causes

Chemical corrosion Surface contamination : attached to the workpiece surface oil, dirt and acid, alkali , salt and other under certain conditions into a corrosive medium , with some elements of stainless steel parts in a chemical reaction , chemical corrosion and rust. Scratch the surface : Various scratches destruction of the passive film , reduced ability to protect the stainless steel , easy to react with the chemical media , chemical corrosion and rust. Cleaning: Cleaning is not clean after pickling passivation resulting residue retention, corrosion of stainless steel parts directly Electrochemical corrosion Carbon pollution : caused by contact with carbon steel scratches and corrosive media, carbon seamless steel pipe manufacturer china the formation of primary cells to produce electrochemical corrosion.

Cutting : Cut slag, rust and other substances spatter adhesion and formation of galvanic corrosion medium to produce electrochemical corrosion . Grilled School : flame heating zone composition and microstructure changes and uneven , and corrosive media, arising form the original battery electrochemical corrosion . Welding : welding area physical defects ( undercut, pores, cracks , lack of fusion , incomplete penetration , etc. ) and chemical defects ( coarse grains , the grain boundary chromium depletion , segregation , etc. ) and corrosive media, arising form the original battery electrochemical corrosion . Material: stainless steel chemical defects ( ingredients uneven , S, P impurities, etc. ) and surface physical defects ( porosity, blisters, cracks, etc. ) is conducive to the formation of primary batteries and corrosive media arising from electrochemical corrosion. Passivation: stainless steel pickling passivation effect is not good cause uneven surface passivation film or thin , easy formation of electrochemical corrosion.

Cleaning: The residue remaining in the stainless steel pickling passivation chemical corrosion product formed electrochemical corrosion and stainless steel parts . Ease stress concentration caused by stress corrosion In short, the stainless steel because of its special microstructure and surface passivation film , making it difficult in general chemical reaction with the media corrosion , but not under any condition not to be corrosion. And incentives in corrosive media ( such as scratches, splashing , cutting slag ) in the presence of stainless steel and corrosion can occur medium slow chemical and electrochemical corrosion reactions , and in certain conditions, the corrosion speed is quite fast and produces corrosion phenomenon, especially pitting and crevice corrosion.

The corrosion mechanism of stainless steel parts for the electrochemical corrosion. Thus, in stainless steel products in the course of processing operations shall take all effective measures to avoid corrosion conditions and incentives for production. In fact, many corrosion conditions and incentives ( such as scratches, splashing , cutting slag ) the appearance quality of the product also has a significant adverse effect , it should have to be overcome .

Hebei ChongSheng Special Steel Pipe Co.,Ltd.