Alloy C276 and Alloy 20: A Comparison
Alloy C276 and Alloy 20 are widely used in marine applications. They share many characteristics, but there are also important differences. This article presents a brief comparison of the two metal alloys, with suggested applications for each. Our team of metal sourcing specialists are always happy to advise on the best alloy for your application, so please get in touch if you are unsure.
Alloy C276
Alloy C276 is a low-carbon alloy containing nickel, chromium, and molybdenum, offering excellent resistance to corrosion, pitting, and cracking, even when subjected to severe conditions. It also has outstanding resistance to sulphuric, hydrochloric, phosphoric acids. The chromium content helps resist oxidising agents, such as cupric and ferric chlorides, while the tungsten content contributes to general resistance.
As such, C276 is especially well-suited to harsh environments in the petrochemical, energy production, and pharmaceutical industries, where it is used in environments that contain chloride ions, chlorine dioxide, organic acids, and seawater.
Machining Properties
Alloy C276 is a versatile metal that works well with a range of CNC and manual machining methods. In welding, the alloy offers excellent resistance to carbide precipitation and retains corrosion resistance in heat-affected areas of welded joints.
Applications
Common applications for C276 include flue gas desulphurisation plants, fans, ducts, valves, chimney linings, and housings. The alloy is used in food processing, pharmaceuticals, and chemical processing in reaction chambers, heat exchangers, valves, piping, and pumps.
Supply
We stock Alloy C276 in 19.05mm to 152.4mm diameter bars, with speedy access to other sizes outside of this range.
Alloy 20
Alloy 20 is an austenitic nickel alloy designed to offer high levels of resistance to sulfuric and nitric acids, making it ideal for power generation, pharmaceutical manufacturing, and food processing applications. It provides good resistance to corrosion and chlorine-induced stress cracking and to abrasive and impact damage. Alloy 20 has a maximum operating temperature of 986°F/530°C.
Alloy 20 has similar properties to Grade 316 Stainless Steel. It is sometimes used as a substitute for stainless in chloride-rich environments – as Alloy 20 offers better resistance to chloride-induced corrosion cracking than 316.
Machining Properties
Alloy 20 is easier and cheaper to fabricate than Alloy C276. Machining speeds and feed rates are comparable, but the niobium content in Alloy 20 improves the alloy’s weldability compared to Alloy C276.
Applications
Alloy 20 is used to manufacture production plant for pharmaceuticals, food, explosives, chemical processing, and petroleum refinement. It is particularly useful in heat exchangers, process piping, mixing tanks, and metal cleaning, due to its exceptional heat resistance.
Supply
We supply round bar Alloy 20 in diameters from 25.4mm to 127mm, in annealed condition to meet ASTM B472.
Premium Steel Alloys From Broder Metals Group
At Broder Metals Group, we stock a wide range of metal alloys, with next day despatch to UK mainland businesses. Our alloys are sourced from UK, US, or European origin with full certification. We can arrange additional testing as required. Please get in touch today for a quote or more information.
