When it comes to choosing the right flanges for your industrial applications, it’s essential to use materials that can withstand corrosion, high temperatures, and pressure.
Many industries opt for high-performance alloys like Hastelloy C276 and Hastelloy C22 for their flange requirements. These alloys are particularly suitable for corrosive environments like chemical processing plants, offshore drilling rigs, and power generation facilities. However, the question remains, what’s the difference between the two alloys, and which one is better? In this blog post, we’ll take a closer look at the properties of Hastelloy C276 flanges versus Hastelloy C22 flanges.
What is Hastelloy C276 Flanges and Hastelloy C22 Flanges?
Hastelloy C276 flanges and Hastelloy C22 flanges are both alloys made with nickel, molybdenum, chromium, and iron. Compared to Hastelloy C22, Hastelloy C276 has higher corrosion resistance in a wide range of exceptionally aggressive media, such as acids mixed with chlorine compounds, including hypochlorite solutions. It also has better pitting or crevice corrosion resistance in reducing, neutral and oxidizing environments than its sister alloy. Furthermore, it is more suitable for applications that involve temperatures up to 1500°F (816°C). In conclusion, the primary differences between the two alloys are their increased levels of chloride stress-corrosion cracking performance and temperature resistance in Hastelloy C276 compared to those found in the other alloy.
Difference Between Hastelloy C276 Flanges vs Hastelloy C22 Flanges
Chemical Composition
Hastelloy C276 and C22 alloys are crafted from a combination of nickel, molybdenum, and chromium. However, they differ regarding the amounts of each component. C276 has a higher nickel concentration, while C22 has more chromium. The nickel in C276 imparts greater corrosion resistance in oxidizing media. Meanwhile, the higher amount of chromium in C22 makes it more resistant to reducing environments like chloride ions or sulfuric acid.
Corrosion Resistance
Hastelloy C276 and C22 flanges are known for their excellent resistance to pitting, crevice corrosion, and stress corrosion cracking. However, both alloys exhibit different levels of corrosion resistance depending on the environment. C276 is more effective against oxidizing media, whereas C22 is better at resisting acidic solutions containing reducing agents like chlorine and sulfuric acid.
Hastelloy C276 and Hastelloy C22 are two of the most popular alloys used for flanges due to their excellent corrosion-resistant properties. Specifically, Hastelloy C276 has superior resistance to pitting corrosion, stress-corrosion cracking and oxidizing conditions compared to other nickel-molybdenum-based alloys such as Hastelloy C22. The alloy exhibits exceptional resistance against chloride-containing environments and acetic, formic, phosphoric and sulphuric acids, even at high concentrations or elevated temperatures.
Mechanical Properties
Hastelloy C276 and C22 possess high strength and toughness properties, but C276 has a slightly higher yield strength. Additionally, C22 is known for its improved fabrication and welding characteristics, making it easier to manufacture complex shapes. Hastelloy C276 and Hastelloy C22 are both nickel-based alloys, but they differ in their mechanical properties. Hastelloy C276 has higher thermal expansion rates and better corrosion resistance than Hastelloy C22. It is also more resistant to oxidation at elevated temperatures than its counterpart. Furthermore, due to its high molybdenum content, it exhibits increased toughness characteristics such as increased ductile stress-rupture strength and creep rupture strength.
Applications
Hastelloy C276 and C22 flanges are used in various industries, including chemical processing, oil and gas, pulp and paper, wastewater treatment, and power generation. However, C22 is more suitable for applications that require greater resistance to chloride-induced stress corrosion cracking, such as seawater applications. Meanwhile, C276 is ideal for applications that require high corrosion resistance in acidic environments.
Cost
The cost of Hastelloy C276 and C22 flanges are both on the higher end of the price spectrum. However, C22 is generally more expensive than C276 due to its higher chromium content and better resistance to reducing environments. Hastelloy C276 Flanges are more expensive than Hastelloy C22 Flanges. The average cost of a Hastelloy C276 flange is between $20 and $30, while that for a Hastelloy C22 flange is between $10 and $15. The difference in price arises from the fact that Hastelloy C276 offers superior strength, corrosion resistance, and thermal stability compared to its counterpart. This makes it ideal for high-pressure environments such as the power industry, chemical equipment manufacturing, and other demanding industries where safety & performance are paramount.
Conclusion:
In conclusion, both Hastelloy C276 and C22 flanges suit various industrial applications. Selecting the right alloy based on the specific environment and corrosion conditions is essential. While C276 offers better resistance to oxidizing media, C22 is more effective in reducing environments. Additionally, C22’s improved fabrication and welding characteristics make it easier to handle in complex shapes. Cost-wise, C22 is slightly more expensive than C276. By considering the alloy’s properties and the operating environment, you can decide which flange material to use for optimal performance, safety, and cost-effectiveness.
