The difference between stainless steel and galvanized steel

 　　Without protection, ordinary carbon steel is still prone to rusting in most environments. Therefore, there are many ways to modify steel to prevent corrosion. Two popular solutions are to use stainless steel or galvanized steel. Although both types of steel can resist rust and corrosion, there are important differences between them that should be understood.

　　What is stainless steel?

　　Stainless steel can resist corrosion because its chemical composition contains additional alloying elements. Although ordinary carbon steel is mainly composed of iron and carbon, stainless steel adds a large amount of chromium to help it resist corrosion. Chromium, sometimes with other alloying elements, is added to stainless steel during the initial melting process and then forms any specific shape.

　　What is galvanized steel?

　　Galvanized steel is a type of steel coated with a layer of zinc, which helps prevent rusting of the underlying steel. This layer is usually very thin, usually measured in thousandths of an inch or micrometer. In order to manufacture galvanized steel, a zinc layer is usually fully added after the steel plate or steel plate is melted, refined, and formed. Sometimes it is even completed after performing a manufacturing process on it (such as bending or welding).

　　How is stainless steel resistant to corrosion?

　　Stainless steel is resistant to corrosion due to the addition of chromium (and sometimes other additional elements). When iron in steel is allowed to combine with oxygen in the surrounding environment, carbon steel will corrode. Chromium in stainless steel can prevent this situation because it combines with oxygen and forms a passivation layer of chromium oxide. In many cases, as long as the chromium content of the steel is large enough, this layer of chromium oxide can prevent the formation of iron oxide (also known as rust). Different grades of stainless steel specify and specify the required amounts of chromium and other alloying elements, which helps to indicate the level of corrosion resistance.

　　How is galvanized steel resistant to corrosion?

　　Galvanized steel is resistant to corrosion due to the zinc coating covering carbon steel. The zinc layer has two purposes:

　　It can prevent oxygen from coming into contact with steel, thereby reducing the possibility of corrosion.

　　Even if the zinc coating is slightly damaged and a small amount of iron is exposed to the atmosphere, the zinc near the rest of the coating is more reactive than steel. This makes zinc easier to attract oxygen molecules than iron, thereby preventing rust on the steel.

　　The difference between stainless steel and galvanized steel

　　Stainless steel usually has better corrosion resistance than galvanized steel. If stainless steel is scratched, it can still maintain corrosion resistance around the affected area. However, if the zinc layer of galvanized steel is damaged, it may expose the underlying carbon steel and make it vulnerable. Moreover, due to the fact that galvanized steel is usually immersed in large amounts of zinc and then cut to appropriate sizes, the edges of the cut are exposed, which may rust.

　　Stainless steel is often considered more aesthetically pleasing than galvanized steel, as it typically has a shiny silver color compared to the dark gray pattern of galvanized steel. However, stainless steel is usually more expensive than galvanized steel.

　　Application of Stainless Steel

　　Stainless steel is typically used for applications where corrosion risk is a major concern and is not allowed. The usage areas of stainless steel include:

　　Food processing equipment

　　Pharmaceutical equipment

　　Aerospace Engine Components

　　Kitchen appliances

　　Certain types of fasteners

　　Application of galvanized steel

　　Galvanized steel is used for applications where corrosion is not desired, but a small amount may be allowed and aesthetics are not a major issue. The applications of galvanized steel include:

　　Pipeline engineering

　　Automotive components

　　Certain types of fasteners

　　Structural beam

　　Metal cabinet

　　Railing

　　Sidewalk

　　traffic sign

　　Telegraph Pole