Hastelloy, a form of anti-corrosion material, is currently categorized into different series of alloys. These include C series, B series, G series, and D series alloys. This classification helps to group and identify the various types of anti-corrosion Hastelloy based on their composition and properties.
The C series alloys are composed of nickel, chromium, and molybdenum. One of the significant advantages of these alloys is that they have an excellent resistance to both oxidizing and reducing environments. This is because the chromium in the alloy forms a protective layer of oxide, while the molybdenum provides resistance to reducing environments. Among the C series alloys, the C-276 alloy is the most widely used and has been utilized for over 40 years since its invention in the 1960s. Its robustness and versatility have been proven through decades of testing. In summary, C series alloys are a reliable choice for environments that undergo varying levels of oxidation and reduction.
The cost-effective C-22 alloy is renowned for its improved corrosion resistance, making it a popular choice among various industries. Additionally, the C-2000 alloy, as a next-generation product, offers an even wider range of applicability, making it ideal for users seeking to enhance equipment longevity and explore novel processes. Currently, the C series alloys have found extensive usage in several sectors, including the fine chemical industry (TDI, PTA, acetic acid/anhydride, acrylic acid, etc.), environmental engineering industry (FGD, sewage treatment), and plate heat exchanger industry.
B-series alloys, known as nickel-molybdenum alloys, are highly renowned for their exceptional resistance to corrosion in fully reducing environments. However, their vulnerability to oxidizing media, like iron and copper ions, poses a significant challenge. Remarkably, even a mere concentration of 50ppm of iron ions can considerably diminish the corrosion resistance of B-series alloys. Consequently, the application range of these alloys is relatively limited, with a primary focus on the production of acetic acid through oxo synthesis. Additionally, they find applicability in certain sulfuric acid recovery systems. Among the various grades, B-3 is currently the most widely used, while B-2 has gradually phased out of the market due to its inferior processing performance.
The remarkable oxidation resistance of G series alloys is attributed to their nickel-chromium-iron composition, except for the G-35 alloy. These alloys are highly regarded for their ability to withstand oxidation, thanks to a significant chromium content. Moreover, the newly developed G-30 and G-35 alloys exhibit excellent resistance to pitting corrosion. Adding a small amount of copper further enhances their resistance to sulfuric acid and hydrofluoric acid. Consequently, G series alloys find extensive applications in environments characterized by strong oxidizing agents and complex mixtures of acids, such as wet phosphoric acid and pickling lines in steel mills. To summarize, the G series alloys are renowned for their exceptional performance in challenging conditions, owing to their unique composition and resistance properties.