What to Look for When Buying Metals & Alloys for High-Temperature Services & Applications
If your business works with alloys in hot environments, choosing the right alloys for a high-temperature service can be confusing. After all, there’s no such thing as uniformity when it comes to working in extreme temperatures.
The alloy you require will depend on the function the metal will serve. Here is a breakdown of some of the world’s most heat resistant metals and alloys as well as other factors to consider before you make a purchase.
What is a Heat Resistant Alloy?
Heat resistant alloys are alloys that perform well at high temperatures, which means they have high creep resistance and strength at high temperatures. The heat resistance levels of these alloys are confirmed by two physical properties, which are the structure of the alloy and the strength of the interatomic bonds within it. The structure required for high treatment alloy is usually achieved by heat treatment.
We would categorise heat resistant alloys into three categories: alloys that are subjected to small amounts of heat stress (seconds to minutes), alloys that are subjected to moderate amounts of heat stress (hours or hundreds of hours), alloys that are subjected to heat stress for long periods of time (thousands of hours). An alloy that is designed to withstand thousands of hours worth of heat will require different.
Heat resistant alloys are classified by their base which could be nickel, iron, titanium, beryllium, and other metals.
Metals & Alloys That Can Withstand High Temperatures
Titanium is a lustrous transition metal which is silver in colour. It possesses low density, high strength and heat resistance. Titanium alloys are resistant to corrosion, chemicals, and heat and can withstand temperatures of 600 degrees plus. It’s also weldable and possesses good fabricability and effectiveness in challenging industrial applications. Common uses of titanium alloys are aeroplanes, missiles and rockets, where heat resistance is vital.
Tungsten is a steel-grey or silver-white metal that possesses high hardness levels, a high melting point and a resistance to air erosion at room temperature. As a refractory metal, it has a high resistance to heat and a high melting point. Tungsten can be used as the base metal for an alloy or a supporting element. Tungsten is commonly used in Combustion liners, turbine exhaust components, aircraft cabin heaters, transition Ducts, industrial furnaces.
3. Stainless Steel
Stainless steel is a metal alloy that contains an iron base, 11% or more chromium as well as other metals like molybdenum and nickel. Stainless steel alloys are known for their resistance to corrosion and heat, which makes them ideal for use in the aerospace, automotive and construction industries as well as specific parts like pressure vessels, steam turbines, boilers and piping systems.
Molybdenum is a refractory metallic element that forms hard, stable carbides which enhance hardenability, strength, toughness, and resistance to wear and corrosion. Molybdenum is most commonly used as a high-temperature metal alloy in steel, cast iron and superalloys in the military and defence industry, semiconductor and speciality machine shops.
Nickel is a naturally occurring silvery-white lustrous metal with a gold tinge. It’s malleable, ductile and has superior strength and corrosion resistance. Nickel is commonly used in stainless steel and other alloys to make them stronger. Nickel alloys are used in gas turbines, power generation, aircraft, speciality engineering and electronics.
Tantalum is a shiny, silvery metal that is soft when pure. It’s virtually resistant to corrosion due to an oxidised film on its surface. Tantalum is particularly useful in high-temperature applications in aircraft engines as well as electronic devices.
Other Factors That Affect An Alloy’s Heat Resistance
Every alloy has properties that make it react differently to other alloys when subjected to prolonged periods of heat.
Therefore, it’s vital that you check the technical data describing the properties of the metal in question before deciding if it’s the alloy for you.
Quite often the temperature is the first, and in some cases, only data point that most people look at when basing their choice of alloy. This is the wrong thing to do.
We have to overstate that you should not choose an alloy on the basis of temperature alone, there are many other things to take into consideration. These include:
- The mechanical properties of the alloy at a specific temperature.
- The alloy’s resistance to oxidation.
- The alloy’s resistance to hot corrosion.
- The metallurgical stability of the material.
Find a Supplier With a Commitment to Quality & Industry Expertise
At NeoNickel we provide the very best speciality metals to companies all over the world. These companies demand high-quality alloys that remain stable, durable and reliable in the face of extreme temperatures.
We have been supplying businesses of all sizes in the aerospace, pharmaceutical, motorsport and thermal processing industries for many years. This experience and expertise allow us to give anyone looking for high-temperature alloys exactly what they need.
Vast Inventory of Heat Resistant Alloys
Our vast inventory includes RA330, which has become the standard material in the steel heat treating industry and combines good oxidation resistance with a high melting point.
Thus, it can tolerate extreme temperatures of up to 1200 degrees C (2200 degrees F). It’s popular because it’s available in the widest range of product forms (sheet, plate up through 4”, threaded bar, nuts, pipe and expanded metal), making it a versatile alloy with many applications in the heat treating and petrochemical industries.
602A is an austenitic heat resistant alloy that displays superior strength in the face of temperatures of up to 1200 degrees C, (2200 degrees F).
In fact, it’s the single strongest and most oxidation resistant wrought alloy currently available for service above 1040 degrees C (1900 degrees F).
The outstanding strength displayed by this alloy has seen its popularity flourish, where it’s used in applications including vacuum furnace fixturing, CVD retorts, rotary calciners and gas-fired radiant tubes.
These are only a few examples of our range of heat resistant alloys that have made NeoNickel one of Europe’s most trusted suppliers of high-quality speciality metals.
Metals that thrive and flourish under the most intense environments. However, this is only the tip of the iceberg. There are many more alloys in our inventory; all with properties suited to different applications at varying temperatures.
If you would like more information on our heat resistant alloys, or you wish to discuss choosing the right alloys for high-temperature service with one of our metallurgists, please contact us and we’ll be happy to help!