When it comes to steel, the mechanical properties of the grade of steel can often mean the difference between a long, efficient life in the most abrasive and wear-intensive applications, and frequent or even catastrophic failure. Understanding these properties is absolutely essential when selecting the best grade of abrasive-resistant steel for your application. Unfortunately, these mechanical properties are very specific, and their exact metallurgical definitions are not widely known outside of metallurgy.
What Properties of Steel Determine Wear and Abrasion-Resistance?
Steel has a number of properties, including: hardness, toughness, tensile strength, yield strength, elongation, fatigue strength, corrosion, plasticity, malleability and creep. The properties that are most important in wear and abrasion-resistant steel are:
HARDNESS is the material’s ability to withstand friction and abrasion. It is worth noting that, while it may mean the same as strength and toughness in colloquial language, this is very different from strength and toughness in the context of metal properties.
TOUGHNESS is difficult to define but generally is the ability to absorb energy without fracturing or rupturing. It is also defined as a material’s resistance to fracture when stressed. It is usually measured in foot lbs. per sq. in or Joules per sq. centimeter. It is important to distinguish this from hardness as a material that severely deforms without breaking, could be considered extremely tough, but not hard.
YEILD strength is a measurement of the force required to start the deformation of the material (i.e. bending or warping).
TENSILE strength is a measurement of the force required to break the material.
ELONGATION (or Ductility) is the “Degree” to which the material can be stretched or compressed before it breaks. It is expressed as a percent of the length being tested and is between the tensile strength and yield strength (i.e. what percent does the material bend before breaking).
What Determines the Key Properties in Wear and Abrasion-Resistant Steel?
These five defining factors in wear and abrasion-resistant steel are dependent on both carbon content and heat treatment. Without enough carbon, the makeup of the steel cannot be changed (as the crystalline structure cannot be broken as it is meant to in the hardening process of wear and abrasion-resistant steels). However, without tempering, the steel structure remains very brittle. Tempering involves heating the steel again to a certain temperature (lower than the critical temperature), and then re-quenching in water, air, or oil to fix the “Temper” at the desired level of toughness and hardness.
These properties are determined by two factors: The chemistry of the metal (i.e. the alloys or elements that are melted or mixed together) and the heat treatment of the steel (or lack thereof).
What’s the ‘Best’ in Wear and Abrasion-Resistant Steel?
There are many types of steel that are suited to many applications. However, if we’re looking at the numbers for wear and abrasion-resistant applications, ENDURA has one the highest tensile, yield and elongations of any wear steels in an “as worked” condition. It also “work hardens” to 15-20% more hardness than other wear steels yet it remains very ductile, will not crack and is easier to machine, bend and weld.
Regardless of the type of steel that best suits your application, always make sure to ask the distributor for a mill certificate for the specific batch (called a Heat) of steel that you are buying. This certificate is based on actual tests performed by the mill at the time of production to determine its Mechanical and Chemical composition.
If you have any questions about the properties of steel, or would like to learn more about ENDURA or any of Titus Steel’s various impact, mold and die, armor plate, pile point, grouser bar, or custom steels, feel free to contact us today.