Alloys vs. Superalloys (HPAs High Performance Alloys) 

Alloys are metallic substances composed of two or more elements, as either a compound or a solution.  The most common metal alloys in industrial applications are carbon steel and brass, an alloy of copper and zinc.  However, special alloys are typically referred to as Superalloys or High Performance Alloys, which are made to withstand high temperatures, high stresses, and often highly oxidizing atmospheres with a resistance to corrosion or oxidation.  Superalloys are nickel based with several key characteristics, including excellent mechanical strength, resistance to thermal creep deformation, and good surface stability.  The development of superalloys has primarily been driven by the aerospace and power industries.  Widely used superalloys are Hastelloy®, Inconel®, Invar ®, and Monel ®. 

Specialty alloys range from common Stainless Steels to Super Duplex Stainless Steels. 

Alloy 316/316L Stainless Steel

Though there are a variety of grades of stainless steel, such as 301, 302, 303, 304, 309, 316/316L and 321.  We will focus on alloy 316/316L because of its wide use in specialty applications.  Alloy 316/316L stainless steel is an austenitic molybdenum-bearing stainless steel containing nickel.

Superalloys, or high performance alloys, provide exceptional mechanical strength and creep resistance at high temperatures, corrosion and oxidation resistance and reliable surface stability.  Superalloys are used extensively in the oil and gas industry, chemical and petrochemical processing, power plants and many other harsh environment applications.  They include a number of special combinations of alloys to make up materials from Monel® to Hastelloy®.

Specialty Alloys – Composition &  Applications

All alloy steels are made from carbon steel and other alloying materials, including aluminum, chromium, copper, manganese, nickel, silicon or titanium.  These metals are combined with carbon steel to create specific properties that allow for increased hardness, strength and/or corrosion resistance.