SUS304 Stainless Steel Microstructure
SUS304 is a stainless steel alloy that is widely used in multiple industrial and commercial applications due to its superior corrosion, heat and wear resistance. In this report, the microstructure of SUS304 stainless steel is discussed in detail.
The microstructure of SUS304 consists mainly of austenite, a hard and ductile crystalline structure. Austenite is a ferrite-containing alloy composed of iron, chrome and nickel. It is the most popular stainless steel alloy because of its excellent mechanical, physical and corrosion resistance characteristics.
The austenite portion of SUS304 is composed of chromium, nickel and iron and is typically comprised of equiaxed grains of approximately 0.2 μm in size. The presence of these grains gives the alloy an excellent level of hardness and ductility, and also results in improved corrosion resistance. The grain boundaries between the grains contain small amounts of carbides and other inclusions, as well as a low interstitial content that further improves the mechanical properties of the alloy.
The microstructure of SUS304 also contains a small amount of ferrite and martensite. Ferrite is a form of iron alloy that contains a significant amount of chromium. Ferrite is relatively soft and poorly resistant to corrosion, and hence is not suitable for use in an SUS304 grade alloy. The martensite structure is a combination of martensite and cementite, both of which are harder than ferrite and are resistant to thermal cycling, making them ideal for use in industrial and automotive parts.
The microstructure of SUS304 is unique due to its inclusion of bainite, a hard and highly corrosion resistant microstructure. Bainite has a fine grain size, which enables it to provide excellent wear resistance and surface finish. A portion of bainite is also present in the outer surface, which serves to provide improved resistance to corrosion and abrasion.
In conclusion, SUS304 is an excellent alloy, which is highly valued for its outstanding corrosion, heat and wear resistance characteristics. Its microstructure is composed mainly of austenite, which provides the alloy with excellent mechanical properties and corrosion resistance, while small amounts of ferrite and martensite are also present to enhance the ability of the alloy to withstand thermal cycling and wear. Finally, small amounts of bainite are also present on the surface, which further improves the corrosion resistance and wear resistance of the alloy.
