Introduction
Hastelloy C276 and Stainless Steel 316 (SS316) are well known anti-corrosive metals. Selecting the correct metal depends on the type of application. No matter if you’re developing equipment for chemical processing, marine, pharmaceutical plants or offshore installations. Selecting the alloy makes a significant difference in performance, safety, maintenance and service life.
This guide compares the characteristics of Hastelloy C276 and SS316 to aid engineers, procurement professionals, and plant designers in selecting the proper material for the application.
What is Hastelloy C276?
Hastelloy C276 is a high-performance nickel-based super alloy for some of the most severe industrial applications. It is trusted for demanding applications for its chemical composition of nickel, molybdenum, chromium, and tungsten which gives an outstanding resistance to oxidizing and reducing chemicals. Hastelloy is extremely resistant to strong chemicals with various organic acids. Hastelloy C276 is also highly resistant to chemical attack and maintains strength at elevated temperatures delivering enhanced resistance to pitting, crevice corrosion and stress corrosion cracking.
What is SS316?
Stainless Steel 316 (SS316) is an austenitic grade with a chemical composition of molybdenum to improve corrosion resistance. This grade of Stainless Steel outperforms various metals in chemical properties. SS316 is a famous grade used in many different industries. Stainless Steel 316 is used in applications such as food processing, pharmaceuticals, marine applications, medical systems and industrial piping.
Difference between Hastelloy C276 and SS316?
| Base Alloy | Nickel-based Superalloy | Austenitic Stainless Steel |
| Major Elements | Nickel, Molybdenum, Chromium, Tungsten | Iron, Chromium, Nickel, Molybdenum |
| Corrosion Resistance | Best against strong chemicals | Better in mild to moderate corrosive environments |
| Chloride Resistance | Exceptional | Good but can get weak to severe chloride exposure |
| Pitting Resistance | Excellent | Very Good |
| Stress in Corrosion Cracking | Outstanding resistance | Moderate resistance |
| Performance in High Temperature | Excellent | Good |
| Resistant to Oxidation | Excellent | Very Good |
| Weldability | Excellent | Excellent |
| Fabrication | More difficult due to higher hardness | Easier to machine and fabricate |
| Service Life | Extremely long in aggressive environments | Long in standard industrial conditions |
| Cost | Significantly higher | More economical |
Chemical Composition Difference
Both metal differ most in the elements they are alloyed with.
Hastelloy C276 consist of more than half nickel with a significant proportion of molybdenum and chromium. This chemical composition makes it resistant to media that quickly corrode normal standard stainless steels. However, the SS316 is based on iron with chromium, nickel and about 2 to 3 percent molybdenum. This alloy is very useful for applications requiring good corrosion resistance, but it cannot be compared to nickel based alloys in highly acidic or oxidizing environments.
Mechanical Strength
Both alloys have very good mechanical properties, but are strong in different operating conditions.
Hastelloy C276 has mechanical stability at high temperatures and under severe chemical attacks. High content of nickel enables it to be resistant to deformation at the same time resistant to corrosion. For regular industrial use, SS316 offers high tensile strength, toughness and ductility. Easy to fabricate, bend, machine and weld, suitable for high volume manufacturing.
Heat Resistance
Metals for high-temperature use should have high strength and corrosion resistance.
Hastelloy C276 is stable even at higher process temperatures typical of chemical reactors, scrubbers and heat recovery systems. SS316 has a similar oxidation resistance but is normally used for moderate temperature applications where chemical exposure is not as severe.
Weldability and Fabrication
Conventional industrial welding processes can be used for both materials.
The lower hardness and greater availability of SS316 make it significantly easier to machine, cut and fabricate. This results in more economical and speedy manufacturing. Due to its work hardening characteristics, Hastelloy C276 needs special tooling and machining practices. Fabrication requires more skill but once fabricated the equipment is extremely durable.
Cost Comparison
Another factor to consider when deciding between these alloys is cost.
SS316 is much less expensive and is available in many different shapes such as valves, fasteners, sheets, pipes and tubes. The higher nickel content, complex manufacturing process and specialized applications make Hastelloy C276 considerably more expensive. But, it is often worth the extra capital cost because of lower maintenance, replacement, and operating costs in corrosive environments and longer operating life.
Which Metal Should You Choose?
The choice depends on your environment where you will select the right metal.
When maximum durability is required, and where the application will need highly corrosive chemicals and elevated temperatures, you must select Hastelloy C276. Even though it will be more expensive but it will deliver outstanding reliability and reduced maintenance costs over time.
Select SS316 when you need reliable resistance to corrosion in food processing, marine, pharmaceutical manufacturing or other industrial service applications. It is the material of choice for many engineering applications due its good properties in terms of performance, ease of fabrication and low cost.
Conclusion
While Hastelloy C276 and Stainless Steel 316 are both high-grade corrosion-resistant materials, they have different applications in industries.
Hastelloy C276 is designed to be used at severe chemical applications where high corrosion resistance and long service life are necessary. However, SS316 is still the industry standard for those applications that demand high corrosion resistance, good hygienic properties and cost-efficient fabrication.
Knowing what conditions the material will be subjected to, what chemicals the material will be exposed to, what temperature the material will be held at, and how much money you can allocate, will help you choose the most cost effective material in the long run. The industry can better optimize equipment life, enhance the equipment’s operation efficiency, and reduce maintenance costs by matching the alloy to the application.
FAQ’s
1. Is Hastelloy C276 more expensive than SS316?
Yes. The high nickel and molybdenum content and outstanding properties under severe operating conditions make Hastelloy C276 much more expensive.
2. Can SS316 be used in chemical processing plants?
Yes, SS316 is used for many chemical processing applications where mild chemicals are used. Hastelloy C276 is generally used with highly aggressive acids, however.
3. Which material is better for marine applications?
In marine applications, where good resistance to seawater is required, SS316 is the best choice. While Hastelloy C276 is a material frequently used in extremely corrosive offshore applications.
From sheets and plates to pipes, tubes, fittings and other industrial products, having the right material is crucial to long-lasting performance and reliability, whether it is Hastelloy C276 or SS316. Our staff will be able to advise you on which alloy is the most appropriate for your application and operating conditions.
Call us today or send an email to export@hansmetalindia.com to send your requirements and get the right Hastelloy C276 or SS316 solution at a competitive price.