High-Alloy Steels
High-alloy steels are very versatile materials with a long history of use in a variety of industries. These steels are valued for their exceptional properties such as strength, toughness, corrosion resistance, and heat resistance. The different elements that comprise high-alloy steels along with their desired properties, allow for the wide range of applications.
The definition of high-alloy steel can be vague since any type of alloy steel with a greater content of alloying elements than a general-purpose steel can be considered high-alloy. Another way to define high-alloy steels is with a general carbon content of less than 0.25%. High-alloy steels typically consist of at least 10% of an alloying element, such as chromium, molybdenum, nickel, and copper. These alloying elements are added in order to achieve a desirable set of properties.
High-alloy steels are classified into martensitic, ferritic, and austenitic grades. Martensitic grade steels contain carbon levels of up to 1.2%, while ferritic and austenitic steels are usually lower in carbon content. Martensitic steels have a high strength to weight ratio and respond well to heat treatment. They are often applied in applications like hand tools, machinery parts, and turbine blades.
Ferritic steels are low-carbon steels with a low yield strength and good oxidation resistance. They are often applied in automotive and piping applications due to their good heat resistance and ability to resist corrosion.
Austenitic steels are non-magnetic stainless steels with a high content of chromium. They are corrosion resistant and have a high toughness. These steels are commonly used in food production and medical instruments, due to their corrosion resistance.
High-alloy steels are also used in nuclear energy applications, nuclear submarines, and aircraft engines. These steels are subject to heavy environmental stress combined with elevated temperatures and need to have a combination of strength and corrosion resistance.
The production of high-alloy steels is more complex than low-alloy steels due to the need to control levels of carbon and alloying elements. Additionally, the alloys must be mixed and poured into a liquid form in order to create the steel. Heat treating is also an important part of the production process and is necessary in order to achieve the desired properties.
High-alloy steels are widely used in a variety of industries due to their combination of strength, corrosion resistance, and heat resistance. With an ever-increasing demand for material with greater performance and durability, high-alloy steels have achieved a secure position as a widely used material.
