Industries that require corrosion‐resistant and durable materials usually face the problem of picking between Hastelloy & stainless steel. Both these alloys have their own particular benefits; however their performance, composition, and cost distinguish them from each other.
This blogpost highlights their properties along with their uses, which will help you pick the best material according to your needs.
What is Hastelloy?
In simple terms, hastelloy is a group of superalloys based on nickel that have excellent heat and corrosion resistance. These alloys usually contain 40% to 70% nickel, as well as notable amounts of chromium & molybdenum. Some grades also contain iron or cobalt. Its popular grades, like C‐22, C‐276, X and B‐2, are manufactured for extreme temperatures or harsh chemical atmospheres.
Also See: What Are Superalloys
What is Stainless Steel?
Basically, stainless steel is an alloy of iron with at least 10.5% chromium, which forms a layer of protection against rust. It also contains nickel. Some of its types also have molybdenum added, to increase corrosion resistance and strength. It has more than 60 available grades – which includes ferritic (409), austenitic (316, 304), duplex & martensitic types. Each grade is intended for a specific use.
Also See: What are Different Types of Stainless Steel
Chemical Composition and Properties
When we analyze their chemical composition & properties, there is a clear difference between Hastelloy and stainless steel.
Hastelloy
Each grade of hastelloy has a distinct composition. For instance, Hastelloy C‐276 consist of following elements:
| Element | Percentage (%) |
|---|---|
| Nickel | 55% to 59% |
| Chromium | 14.5% to 16.5% |
| Molybdenum | 15% to 17% |
| Tungsten | 3% to 4.5% |
| Iron | 4% to 7% |
Hastelloy alloys are excellent in resistance to chlorides, acids and extreme temperatures. They maintain their strength up to 1100°C. These alloys also resist crevice and pitting corrosion.
Stainless Steel
Stainless steel is available in several grades, but all of its types contain at least 10.5% chromium. The grade 316, which is a common type, has the following composition:
| Element | Percentage (%) |
|---|---|
| Iron | Balance |
| Nickel | 10% to 14% |
| Chromium | 16% to 18% |
| Carbon | 0.08 max |
| Molybdenum | 2% to 3% |
Stainless steels are famous for their corrosion resistance. They have high tensile strength which ranges from 500MPa to 700 MPa for grades 316 & 304. They also have excellent ductility.
Performance Comparison of Hastelloy and Stainless Steel
1. High‐Temperature Resistance
Hastelloy:
Hastelloy maintains its stability and strength even at extreme temperatures. Most grades can withstand heat up to 1100°C (2000°F). For this reason, manufacturers select it for heat exchangers, reactors and aerospace components that must withstand extreme heat.
Stainless Steel:
Standard stainless steel performs well at temperatures up to 800°C (1472 F). Some special types – such as 310 stainless steel – can withstand even more elevated temperatures but still not reach the maximum limit of Hastelloy.
2. Corrosion Resistance
Hastelloy:
Hastelloy offers excellent protection against corrosion. Its nickel content, which is usually between 57% to 65%, creates an oxide layer that can repair itself. These properties shield the alloy from harsh settings, such as alkalis, acids and seawater. Despite surface scratches, Hastelloy resists crevice and pitting corrosion. These properties make it great for marine sector and chemical processing.
Stainless Steel:
Stainless steel resists rust due to its chromium oxide coating. However this layer cannot repair itself if scratched. Stainless steel performs well in slightly corrosive environments. In high acidic or chloride settings, it can be susceptible to stress corrosion cracking.
3. Strength and Durability
Hastelloy:
Hastelloy has more hardness & tensile strength in contrast to stainless steel. For example Hastelloy C‐276 has a yield strength of approximately 283 MPa and tensile strength of 690 MPa.
Stainless Steel:
Grades such as 316 & 304 stainless steels have a tensile strength of 505 MPa to 515 MPa and a yield strength of approximately 205 MPa to 215 MPa. These steels are ductile as well as strong. But they do not have the strength of Hastelloy under severe conditions. Some stainless steels may be more susceptible to stress corrosion cracking.
Industrial Uses of Hastelloy
Aerospace Sector
Aerospace engineers use Hastelloy for exhaust systems, turbine blades and cabin heaters. Its ability to preserve high stability and strength at elevated temperatures makes it a dependable material for jet engines and other critical flight parts.
Chemical Processing
Hastelloy is the recommended pick for heat exchangers, reactors and pressure vessels that handle harsh chemicals. Its excellent resistance to oxidizing & reducing environments makes it good for processing hydrochloric acid and sulfuric acid.
Marine Industry
Hastelloy is used for valves, pumps and piping systems in seawater desalination plants and offshore platforms. Its great compatibility with seawater helps avoid corrosion damage, which is common in harsh marine environments.
Industrial Uses of Stainless Steel
Medical Devices
Laboratories and hospitals depend on stainless steel for medical implants, surgical instruments and hospital furniture. This metal withstands sterilization and resists rust very well.
Food and Beverage
Food processing equipment, storage tanks as well as packaging machinery usually use stainless steel. The material’s non‐reactive surface keeps food safe. It also adheres to EFSA & FDA regulations.
Construction
Stainless steel is used in advanced construction projects for decorative and strength purposes. You’ll see it in beams, handrails, cladding and roofing. Its weather resistance and strength help buildings last for a long time, even in harsh settings like industrial or coastal areas.
Cost Assessment
Hastelloy
Hastelloy is considerably more expensive as compared to stainless steel. A common Hastelloy grade “C‐276” generally sells for $15 ‐ $20 per pound. The reason behind this high price is its costly raw materials and complex manufacturing. This is why Hastelloy can be many times more costly than stainless steel of the same shape & size.
Stainless Steel
Stainless steel is available at a very low cost. Common grades like 304 to 316 cost around $2 ‐ $4 per pound. This less price is due to simple ingredients as well as easy manufacturing. For this reason, stainless steel remains the favoured option for industries that require both cost savings and efficiency.
Working with experienced manufacturers like RICHCONN can help you reduce waste and use materials more effectively. In this way you can make premium alloys like Hastelloy more cost‐effective for your intended use.
Machinability and Fabrication
Hastelloy
Machinability:
Machining Hastelloy is difficult due to its rapid hardening during cutting and its high strength. The use of specialized equipment, such as PVD‐coated carbide or standard carbide inserts, is essential. Cutting speeds should be limited to 70 m/min to get a better finish while decreasing tool wear at the same time. Due to these machining hurdles it is necessary to pick a manufacturer with skills & experience in superalloy tooling and modern CNC processes, such as Richconn.
Weldability:
Hastelloy can be welded efficiently but heat must be managed properly. Without proper heat management, cracking & brittleness can arise in the material. TIG welding is the most favoured option for joining Hastelloy.
Stainless Steel
Machinability:
Machining stainless steel is faster and easier than Hastelloy. For martensitic stainless steel, cutting speeds can reach 180 m/min. Most tasks can be performed with commercial-grade carbide tools.
Weldability:
Stainless steels, specially the austenitic types, are easy to weld. There is a low probability of cracking; which is why common TIG or MIG welding approaches are generally preferred.
Also See: MIG vs TIG Welding
Decision‐Making Comparison
| Factor | Hastelloy | Stainless Steel |
|---|---|---|
| High-Temperature Stability | Highly effective up to 1100°C | Moderately effective up to 800°C |
| Strength & Durability | Superior tensile strength | Good, with specific grades offering high strength |
| Corrosion Resistance | Superior in aggressive settings | Good in mild to typical conditions |
| Fabrication Ease | Intermediate to difficult | Easy to intermediate |
| Cost | Significant | Average to low |
To Sum Up
Your decision between Hastelloy & stainless steel should depend on your budget and needs. Hastelloy gives great corrosion resistance and strength in challenging, high‐temperature conditions, but it is more expensive. Conversely stainless steel is easy to machine and is budget‐friendly for general use.
Richconn produces Hastelloy and stainless steel components. Our factory has obtained ISO 9001:2015 certification. We provide rapid prototyping services as well as mass production services. Please contact us if you need custom CNC machining solutions.
Related Questions
Should I pick stainless steel or Hastelloy for food‐grade equipment?
Stainless steel is the common pick for food‐grade equipment. It is easy to clean, corrosion‐resistant, budget‐friendly and has an established track record of safety in food processing.
Is stainless steel, like Hastelloy, good for high‐temperature use?
No, it is not. Hastelloy preserves its strength at temperatures up to 1100°C and is protected from corrosion. While, stainless steel is only dependable up to 800°C and it can become brittle or lose its shape in extremely hot, corrosive conditions.
