Known for its versatility and wide range of applications, steel is a strong and durable alloy made up primarily from iron and carbon. In today’s world, abrasion resistant steel is used in everything from construction and infrastructure to car parts and machinery.
Steel has several properties, two of which are hardness and hardenability. Both properties refer to different characteristics of abrasion resistant steel and can be measured in different ways. Let’s explore what each of these properties mean and the key differences between them.
The Hardness of Steel
What does hardness of steel actually mean? It is the measure of steel’s resistance to surface deformation, which includes the gouging, chipping, shearing, and cutting of steel.
Hardness Testing
Hardness is measured using specific examinations such as the Rockwell, Brinell, or Vickers Hardness Tests. Each one of these tests entails the process of pressing a hard indenter into the surface of the abrasion resistant steel and measuring the depth of the indentation.
Factoring in Other Elements
Alloying elements such as carbon, chromium, and manganese can impact the hardness of abrasion resistant steel. For example, carbon can increase hardness by forming hard carbides. Chromium on the other hand can enhance corrosion resistance, and manganese contributes to strength and toughness in steel alloys.
Heat Treatments
The types of heat treatments that are used to induce hardness are quenching and tempering. Quenching involves rapid cooling of steel from a high temperature, which creates a hardened structure by freezing the atoms in place.
Tempering then reduces hardness and increases toughness by reheating the quenched steel to a specific temperature and then cooling is slowly.
Microstructure is important to the hardness of steel because it involves the arrangement and alignment of grains, as well as the different phases the steel undergoes during heat treatment. For example, martensite, a phase formed during quenching, is much harder than ferrite, which is a softer phase.
Applications
Hardness is a key property for applications requiring high resistance to surface wear and abrasion. This includes equipment such as Grizzly decks, ore pockets, chutes, and conveyors, where maintaining structural integrity and longevity under harsh conditions is essential.
The Hardenability of Abrasion Resistant Steel
Hardenability is the ability of steel to harden throughout its thickness when subjected to a heat treatment process. It is the capacity of steel to form martensite throughout its entire cross-section when subjected to the appropriate heat treatment, ensuring uniform hardness and strength.
How Is It Measured?
Hardenability is measured using the “end-quench test,” where a standardized sample is heated to an austenitizing temperature and then quenched at one end with water. Hardness is measured at various distances from the quenched end to determine the depth of hardness penetration.
Factors affecting hardenability include alloying elements, grain size, and the cooling rate during quenching. Slower cooling rates allow the formation of more martensite, a very hard and brittle phase of steel created by rapid cooling.
Applications
Hardenability is important for applications of abrasion resistant steel where consistent hardness is required throughout the thickness, such as automotive gears, railways tracks, and heavy machinery components. Even as the surface hardness wears down, the steel will continue to limit abrasion and maintain durability due to its hardenability.
The Key Difference between Hardness and Hardenability in Steel
When it comes to steel, hardness measures the surface resistance to deformation, while hardenability refers to the steel’s ability to be hardened throughout its depth.
Find Out How Titus Steel’s ENDURA and ENDURA Dual Can Enhance Your Project
ENDURA and ENDURA Dual with titanium carbides both “work harden” with impact. They start at relatively low hardness, making them easier to machine and bend, but with each impact, they become progressively harder.
Additionally, they are the only abrasion resistant steels that are oil quenched instead of water quenched, allowing for slow cooling during the heat treatment process. This results in a uniform microstructure that resists gouging and tearing.
For a steel that is easier to process yet becomes the hardest abrasion resistant steel available upon impact, choose ENDURA and ENDURA Dual.
Contact Titus Steel today to receive a customized quote or to learn more about our products.