AISI 321 Alloy
AISI 321 is an austenitic chromium-nickel stainless steel containing titanium. This stainless steel alloy is designed to offer excellent high-temperature performance and remarkable corrosion resistance in environments with elevated temperatures and/or lower pH values. Due to its titanium content, AISI 321 is more corrosion-resistant and harder than standard types of stainless steel. Furthermore, AISI 321 offers good creep fatigue strength and thermal stability at elevated temperatures (up to 700°C). As a result, this alloy is extensively used in the production of a variety of materials and products, including chemical, automotive and petrochemical process equipment, pressure vessels and components exposed to corrosive environments and high-temperature gases.
The composition of AISI 321 stainless steel consists of iron (Fe) (89%), chromium (Cr) (18%), nickel (Ni) (10%) and titanium (Ti) (0%). During the manufacturing process, an additional amount of titanium is added to the alloy in order to reduce its Ni content and stabilize its structure. The presence of titanium helps reduce the risk of carbide precipitation. As a result, for applications in which carbide precipitation is an issue, AISI 321 is a preferred choice.
The melting point of AISI 321 is approximately 1450°C. This alloy is usually produced in the forms of bars, sheets, plates and tubes. In terms of its mechanical properties, AISI 321 possesses good tensile strength and excellent cold workability.
This stainless steel alloy is easy to weld. When welding, it is recommended to use the same type of filler metal as the base metal. This should be combined with proper preheating, interpass temperatures and post-weld heat treatment. Failure to do so may result in cracking and excessive dilution of the weld pool.
In terms of its applications, AISI 321 is suitable for use in a wide range of industries, including chemical, automotive, petrochemical and food processing. It is also used in the manufacture of an extensive variety of components, such as piping, valves, pressure vessels and columns.
Due to its superior resistance to corrosion, AISI 321 is suitable for use in environments with elevated levels of chlorine, sulfuric or hydrochloric acid. This alloy is also suitable for use in applications which involve contact with food or beverages.
To summarize, AISI 321 is a versatile austenitic chromium-nickel stainless steel containing titanium. This alloy offers excellent corrosion resistance and high-temperature performance, making it suitable for a range of applications in various industries.
