In general, work hardening is the strengthening of a material or polymer by plastic deformation. This strengthening happens because of dislocation movements and dislocation generation inside the crystal structure of the material. As the material is deformed, these dislocations interfere with the motion of grains within the structure, which increases the energy needed for further deformation, effectively making the material harder and stronger.
Work Hardening Steel: Also Known as Strain Hardening or Cold Worked Steel
When it comes to work hardening steel, which is also known as strain hardening steel or cold worked steel, this refers to a type of steel that becomes stronger and tougher through mechanical deformation rather than heat treatment. The process does not rely on external heating but instead builds strength from internal structural changes brought on by applied stress. This mechanical deformation can take place during forming, shaping, or in-service wear.
The Process of Work Hardening Steel
This process involves subjecting the steel to plastic deformation such as bending, rolling, or hammering, which causes its crystal structure to change in a way that increases its hardness and strength. The more the steel is “hit” or “impacted,” the harder it becomes. Some work hardened steel is heat treated to a specific hardness before they are put into service, but their key property is that they continue to harden once exposed to further mechanical stress.
- Initial State – Soft and Ductile: Work hardening steel starts in a relatively soft and ductile state. Its internal crystal structure consists of tiny grains that can slide past one another, allowing for easy plastic deformation without significantly increasing its strength.
- Plastic Deformation – Grains Begin to Shift: When the steel is subjected to mechanical forces, its grains are forced to move and slide against one another. This movement causes dislocations, which are essentially defects in the crystal lattice structure. These dislocations hinder the sliding of grains and require energy to move.
- Resistance to Movement – Dislocations Accumulate: With continued deformation, the number of dislocations increase. They become entangled and piled up, making it more difficult for the grains to slide and for the steel to deform. This is the start of increased resistance to mechanical stress.
- Increased Strength and Hardness – Structural Changes Take Hold: The tangled dislocations act as barriers to deformation, effectively hardening the material. The steel becomes more resistant to bending, denting, gouging, and wear, especially under repeated or heavy impact.
- Strain Hardening – Strength Without Chemical Change: As the process continues, the steel becomes more and more work hardened. This phenomenon is often referred to as strain hardening. The steel’s properties change without altering its chemical composition, which sets it apart from heat treated steels.
What is Hardened Steel Used For?
Work hardened steel is commonly used in various applications, including mining chutes, conveyors, grizzlies, screens, bucket lips, and components requiring both strength and ductility. Moreover, this type of steel is also used for the heading of bolts and cap screws, and for the finishing of cold rolled steel.
What is ENDURA Steel?
ENDURA Steel from Titus Steel is a unique work hardening steel that can handle wear eight times more than mild steel. ENDURA starts off as a relatively low hardness steel but can work harden to a very high hardness steel. It is ideal for situations where material is subjected to heavy impact and abrasion.
Due to the process of heat treatment and quenching in oil rather than water, the microstructure of this steel is very homogeneous and limited when it comes to tearing, shearing, and gouging. It’s helpful to think of ENDURA’s microstructure as a row of pick-up sticks neatly lying next to one another, rather than mixed up in a pile. This orderly structure gives ENDURA superior toughness in extreme conditions.
The TRIP Effect: Transformation Under Stress
INDUSTEEL, a steel producer distributed by Titus Steel, has developed a revolutionary metallurgical phenomenon known as the TRIP (Transformation Induced Plasticity) Effect, which is achieved by the spontaneous rearrangement of metallic atoms under stress.
Think of catching a baseball. If you make your hand stiff to catch the ball, the impact of the ball can cause damage. But if you loosen your hand to catch the ball, the impact of the catch isn’t as severe.
This is how the TRIP Effect of ENDURA Steel works when rocks, gravel, and other abrasive materials crash into the metal, and why it outlasts all the other wear steels.
Frequently Asked Questions
What is the difference between work hardening and heat treatment?
Work hardening strengthens steel through mechanical deformation, while heat treatment changes the steel’s properties by heating and cooling.
Can work hardened steel be welded?
Yes, but with great care. Welding can locally alter the hardened structure, so pre- and post-weld treatments may be required depending on the application.
What industries use work hardened steel?
Industries like mining, construction, and manufacturing use work hardened steel in high-wear parts such as chutes, bucket lips, and screens.
Key Takeaway
Work hardened steel is a game-changer for industries that require materials to withstand constant wear and stress. Its unique ability to become stronger and more durable as it’s deformed makes it the ideal choice for high-performance applications, ultimately improving both the efficiency and longevity of equipment.
Why Choose Titus Steel for Your Work Hardening Steel Needs?
Contact Titus Steel today to learn more about ENDURA Steel. It’s a unique, easy-to-process work hardening steel with a homogeneous microstructure, and the ability to work harden into an extremely strong and tough material.
Whether you’re working in mining, construction, or any high-impact industry, ENDURA provides unmatched performance and durability for the most demanding environments.