Question

 "Corrosion in the case of 316L stainless steel". What should be included like mechanisms, previous studies?

Answer 1

1.steel corrodes almost always only by pitting . Its always an electrochemical ( galvanic) corrosion and not erosion.The corrosion proceeds in electrolytes aqueous solutions of various acids and salts.

2.cause corrosion of stainless steel is the local losing of passivation an the surface (Thin cr2o3 layer that normally protests the surface is distroyde in some places by means corrosion medium).

3.Mechanism of corrosion is to form a galvanic element between passivated( cathode) and not passivated( anode) surface.

4.Principles and prevention of crevice corrosion:

Crevice corrosion along with stress corrosion cracking, is one of the major corrosion hazards to stainless steel.carefull selection of the steel grade can help reduce the risk attack, but a brief review of the mechanism and factors that promote crevice corrosion should help reduce the risk of attack shielding corrosion be neath surface deposit works in a similar way to crevice corrosion.

5.General Principles for srlselect of stainless steel:

The main factors in the selection process for stainless steel is corrosion resistance.careful consideration of the application should be done to enable a choice of grade with suitable corrosion resistance whilst keeping costs to an economic minimum other consideration such as mechanical properties (strength and toughness), physical properties (magnetic,permeability ) and forming fabrication and joining methods available should be secondary.

6. corrosion mechanism in stainless steel:

In certain aggressive environmental some grades of stainless steel will be susceptible to localised attack. six corrosion mechanism are described in this article, namely pitting corrosion, crevic corrosion, bimetallic ( galvanic) corrosion, stress corrosion cracking (SCC), general(uniform) corrosion and intergranular(IGC), sometimes know as intertcrystalline or IC) or weld decay attack.