Stainless Steel 316H

Products Description

Alloy 316H (UNS S31609) is a high carbon modification of Alloy 316, specifically developed for elevated temperature service. It offers higher strength at elevated temperatures and is commonly used in structural and pressure vessel applications where temperatures exceed 932°F (500°C). The higher carbon content in Alloy 316H contributes to increased tensile and yield strength compared to Alloy 316/316L. Additionally, its austenitic structure provides excellent toughness even at cryogenic temperatures.In terms of corrosion resistance, Alloy 316H is comparable to Alloy 316/316L and superior to Alloy 304/304L in moderately corrosive environments. It is frequently used in process streams containing chlorides or halides. The alloy exhibits resistance to atmospheric corrosion, as well as moderately oxidizing and reducing environments. It is also resistant to corrosion in polluted marine conditions.In the annealed condition, Alloy 316H is non-magnetic. It cannot be hardened by heat treatment, but it can undergo hardening through cold working. The alloy is easily weldable and can be processed using standard shop fabrication practices.

Overall, Alloy 316H is a suitable choice for applications requiring high strength and corrosion resistance at elevated temperatures. Its combination of mechanical properties, corrosion resistance, and fabricability makes it a versatile option for a range of industries and environments.

Corrosion Resistance

Alloy 316H is comparable to Alloy 316/316L and superior to Alloy 304/304L. It will exhibit similar corrosion resistance to Alloy 304/304L in process environments that do not attack the latter. However, there are some exceptions to this general rule.In highly oxidizing acids such as nitric acid, stainless steels containing molybdenum are generally less resistant, including Alloy 316H. Therefore, it may not perform as well as other alloys in such environments.Alloy 316H performs well in sulfur-containing service, making it suitable for applications encountered in the pulp and paper industry. It can be used in high concentrations of sulfur at temperatures up to 120°F (38°C).The alloy also demonstrates good resistance to pitting in phosphoric and acetic acids. It performs well in boiling 20% phosphoric acid. Additionally, Alloy 316H is suitable for use in the food and pharmaceutical process industries, where it can handle hot organic and fatty acids without significant product contamination concerns.Alloy 316H exhibits good resistance to corrosion in fresh water service, even with high levels of chlorides. It also offers excellent resistance to corrosion in marine environments under atmospheric conditions.The higher molybdenum content of Alloy 316H ensures superior pitting resistance compared to Alloy 304/304L, particularly in chloride solutions and oxidizing environments.

Chemical Analysis

Weight % (all values are maximum unless a range is otherwise indicated)

Mechanical Properties

Values at 68oF (20oC) (minimum values, unless specified)