Grade 316 stainless steel sheet offers greater corrosion resistance than its standard grades, due to increased nickel and molybdenum content that enhances resistance against atmospheric and general corrosive environments.
316 is easily fabricated using any standard methods; post-weld annealing should be performed post-weld to reduce stresses. Its resistance to chlorides makes it ideal for marine or polluted environments.
Corrosion Resistance
Stainless steel alloys are widely utilized in environments requiring superior corrosion resistance, such as marine environments and highly acidic environments, underwater equipment, medical instruments, food and pharmaceutical applications, etc. Their high content of chromium provides a natural defense mechanism against rusting and corrosion; further increased by adding molybdenum into 316 grade metal, these alloys are well suited to more extreme environmental conditions.
316 grade stainless steel can be successfully utilized in environments that contain chlorides, such as marine environments. It resists pitting and crevice corrosion better than many other grades while performing admirably in various acids such as nitric acid and sulfur-containing solutions.
Steel Grade 302 offers excellent corrosion resistance in polluted marine environments and can withstand wide temperature ranges without embrittlement due to its higher nickel content and lower carbon level compared with grades like 304.
Molybdenum’s addition to 316 stainless steel makes it more resistant to various industrial processing chemicals and high-saline environments, including coastal regions where de-icing salts are frequently used. Furthermore, its corrosion resistant qualities stand up well when subjected to 20% phosphoric acid boiling or other organic acids.
As with other austenitic grades of stainless steel, grade 316 metal stands up well against corrosion caused by chlorine; its high molybdenum content gives it exceptional resistance against pitting and crevice corrosion, with solutions up to 2000ppm chloride being handled easily; plus it exhibits excellent seawater corrosion resistance as well as in acetic acid vapour environments.
These features make 316 grade sheet and plate an excellent choice for chemical processing applications, building exteriors, or anywhere where salt spray or other aggressive environments may exist.
As with other stainless steels, 316 grades can be readily welded using conventional techniques. However, higher carbon levels in 316L may prove useful when corrosion in welds or heat-affected zones is a concern, since welding these grades helps avoid sensitization caused by welding lower carbon grades of stainless steel.
Strength
316 is an austenitic stainless steel alloy with superior strength and corrosion resistance, ideal for marine, chemical, paper textile and food service applications. Compared to 304, however, 316 contains more molybdenum which helps improve pitting-type corrosion resistance as well as intergranular attack resistance and creep strength improvements.
This grade of steel is an ideal material for fabrication, due to its excellent ductility. This makes it easy to form by welding or cold working and machine with more power required than carbon steels; solution annealing after machining may be required to preserve strength and corrosion resistance properties, although GTAW/TIG, MMA / stick welding techniques don’t need preheating or postheating before use.
As with other austenitic grades, 316 can be cold rolled to achieve superior forming characteristics and make an ideal material choice for thin sheets and strips. Furthermore, hot rolling provides higher strengths needed for thicker plates or structural parts.
Cold rolled steel has lower tensile strength than its hot-rolled equivalent, yet is easier to work and offers greater corrosion resistance than its counterparts. As such, cold-rolled steel makes an excellent material choice for manufacturing household appliances and kitchen utensils, due to its ability to withstand repeated exposure to acids and alkalis found in food processing and coastal buildings.
When choosing the appropriate stainless steel alloy for your application, it’s crucial that you understand its different forms and grades available – particularly SS304 and SS316, two popular choices used today. Selecting the appropriate grade ensures optimal results from your project – Cut2Size Metals is here to assist with finding just the right steel for you – contact us now to explore our inventory or request a quote!
Weldability
316 stainless steel can be easily welded using most fusion welding methods (GTAW / TIG, GMAW / MIG and MMAW/stick). No preheating is required nor temperature regulation of the interpass range is needed; typically using filler metals of similar grade for welding to retain corrosion resistance and strength; its low carbon content helps avoid sensitization (harmful precipitation of carbides in the weld zone).
Titanium and niobium additions can be especially advantageous in applications where welding joints will be exposed to hydrogen chloride, helping stabilize structures and increase corrosion resistance while simultaneously providing sub-zero mechanical properties.
Comparative to carbon steel, 316 is among the easier austenitic grades to forge, bend, upset and cold form; however, due to its increased ductility it requires more power for processing than other materials.
Molybdenum’s addition to 316 increases general corrosion resistance, enhances pitting and crevice corrosion resistance in oxidizing environments, and improves erosion resistance in chloride solutions. Furthermore, this provides increased strength at elevated temperatures.
As with other chromium nickel austenitic grades, 316 is non-hardening; although heat treatments can harden it temporarily, the resultant case will not be as tough as an annealed surface.
316 stands up well against seawater corrosion and makes for an excellent marine application choice. Corrosion occurs when in contact with many common organic acids such as sulfuric, hydrochloric and acetic acids as well as formic acid or alkaline chlorides. 316L offers similar corrosion resistance to its counterpart, yet is better weldable and less susceptible to sensitization due to chromium precipitation. Furthermore, adding titanium increases high temperature stability – this is especially useful in chloride environments. Titanium-clad standard or straight 316 is an increasingly popular variant, due to its superior carbide-forming ability and reduced likelihood of intergranular corrosion at grain boundaries in welded areas. As an additional advantage, high welding temperatures without compromising strength are possible with titanium alloy welding processes.
Finish
Finishes play an essential role in corrosion resistance when working with 316 stainless sheet metal, especially its marine grade counterpart, known as 316L (marine grade stainless steel). As it contains molybdenum-bearing alloys such as molybdenum-bearing alloy 316L offers advanced corrosion resistance compared to other austenitic grades; therefore it’s often chosen in environments that would corrode quickly otherwise. Welders tend to prefer this grade due to its lower carbon content that helps avoid harmful precipitation between 800o F and 1500o F temperatures.
The 316L grade of stainless steel offers excellent creep and tensile strengths at elevated temperatures, as well as superior corrosion resistance against sulfuric acid, hydrochloric acid and chloride solutions as well as various reducing acids including acetic acid, phosphoric acid and nitric acid. Furthermore, it can even withstand certain types of salts such as sodium chloride potassium chloride and lithium bromide without corrosion occurring.
316 stainless steel can come in different finishes to meet specific applications and customer preferences. At Stainless Supply, our #2B finish features mill polishing with a dull, non-reflective appearance; this finish can often be found used in deep drawing applications or auto exhaust components where more decorative or shiny finishes are not necessary; while #4 features smooth, brushed linear appearance which is used widely across commercial and residential stainless steel applications including sinks, kitchen equipment and automotive hardware.
No. 3 and No. 4 finishes can also be produced through mechanical polishing using an emery cloth belt on No. 2B substrates, creating uniform appearances which make them popular choices in numerous industrial and commercial settings.
316 stainless steel can also be provided with architectural and custom finishes such as satin, hairline, brush, mirror and more. This process can be achieved through special temper mill processes, final reduction stands, special pickle processes or combinations thereof; buyers and producers typically agree upon these finishes during a larger purchase contract, which usually details its form, form and amount of finishing.
