Alloy 316H

A High Carbon Version of 316 Austenitic Stainless Steel making it More Suitable for Elevated Temperature Service.

Available thicknesses for Alloy 316H:

General Properties

Alloy 316H (UNS S31609) is a high carbon modification of Alloy 316 developed for use in elevated temperature service. The alloy has higher strength at elevated temperatures and is used for structural and pressure vessel applications at temperatures above 932°F (500°C). The higher carbon content of 316H also delivers higher tensile and yield strength than 316/316L and its austenitic structure provides excellent toughness down to cryogenic temperatures.

The corrosion resistance of Alloy 316H is comparable to Alloy316/316L and is superior to Alloy 304/304L in moderately corrosive environments. It is often used in process streams containing chlorides or halides. The alloy resists atmospheric corrosion, as well as, moderately oxidizing and reducing environments. It also resists corrosion in polluted marine conditions.

Alloy 316H is non-magnetic in the annealed condition. It cannot be hardened by heat treatment, however the material will harden due to cold working. It can be easily welded and processed by standard shop fabrication practices.

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Chemical Analysis

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

Mean Coefficient of Thermal Expansion

Temperature Range
°F	°C	in/in °F	cm/cm °C
68-212	20-100	8.9 x 10-6	16.0 x 10-6

Mechanical Properties

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

Corrosion Resistance

In most instances the corrosion resistance of Alloy 316H will be comparable to Alloy 316/316 L and will have superior corrosion resistance to Alloy 304/304L. Process environments that do not attack Alloy 304/304L will not attack this grade. One exception, however, is in highly oxidizing acids such as nitric acid where stainless steels containing molybdenum are less resistant. Alloy 316H performs well in sulfur containing service such as that encountered in the pulp and paper industry. The alloy can be used in high concentrations at temperatures up to 120°F (38°C).

Alloy 316H also has good resistance to pitting in phosphoric and acetic acids. It performs well in boiling 20% phosphoric acid. The alloy can also be used in food and pharmaceutical process industries where it is utilized to handle hot organic and fatty acids where product contamination is a concern.

Alloy 316H performs well in fresh water service even with high levels of chlorides. The alloy has excellent resistance to corrosion in marine environments under atmospheric conditions.

The higher molybdenum content of Alloy 316H assures it will have superior pitting resistance to Alloy 304/304L in applications involving chloride solutions particularly in oxidizing environments.

Pitting Corrosion Resistance		Crevice Corrosion Resistance
PRE	CPT	CCT
24	20±2	<0

Pitting Resistance Equivelant (PRE) is calculated using the following formula: PRE = %Cr + 3.3 x %Mo + 16 x %N
Corrosion Pitting Temperature (CPT) as measured in the Avesta Cell (ASTM G 150), in a 1M NaCl solution (35,000 ppm or mg/I chloride ions).
Critical Crevice Corrosion Temperature (CCT) is obtained by laboratory tests according to ASTM G 48 Method F.

NOTE: The information and data in this product data sheet are accurate to the best of our knowledge and belief, but are intended for informational purposes only, and may be revised at any time without notice. Applications suggested for the materials are described only to help readers make their own evaluations and decisions, and are neither guarantees nor to be construed as express or implied warranties of suitability for these or other applications. Stainless Steel, Nickel Alloy and Titanium products are classified as sheet if the thickness of the metals is less than 3/16” (4.7mm). If the thickness of the metal is 3/16” (4.7mm) or more, then it is considered a plate.